pachypo'da: having a thick stalk from Greek pachys, "thick," and poda, "foot or stalk."

pacif'ica: from the Latin pacificus, meaning "peace-making, peacable," and from a botanic standpoint probably meaning "of the Pacific Ocean or the general Pacific area."

Pack'era: named for botanist John George Packer (1929-2019), specialist on the flora of Alberta and on Arctic and alpine

flora, instructor in the Department of Botany at the University of Alberta 1958-1988, co-author with Cheryl Bradley of Checklist of the rare vascular plants in Alberta (1984), one of the editors of the English edition of Flora of the Russian Arctic (2000), co-author with his wife of Some Common and Interesting Plants of San Miguel de Allende (Mexico). He also revised E.H. Moss's Flora of Alberta (1983), worked to protect Mountain Park in the Canadian Rockies from an open-pit coal mine, and was a contributor and on the editorial committee for Flora of North America. He was born in Reading,

England, and after doing his compulsory national service obtained a BSc and PhD from the University of London. In 1957 he joined the Botany Department at the University of Alberta as professor and Curator of the Vascular Plant Herbarium. He and his family built a log cabin on the sandhills northeast of Edmonton which was burned in the wildfires of 2008. One of his students, John Bain, described him as a "sometimes irascible old school gentleman with a penchant for big cigars [and] a humorous intellectual, generous with his time and knowledge." The genus Packera was published by Áskell Löve and Doris Benta Maria Löve in 1975 and is called ragwort. (Photo credit: Trinity Funeral Home, Edmonton)

pago'da: with the shape of a pagoda. A website of the Illinois State Museum says: "The species name, pagoda refers to the appearance of the leaf when it is viewed with the leaf tip pointed towards the ground. Looking at the leaf from this perspective, the angle of the lobes resembles the overlapping roofs of an oriental pagoda." Rafinesque’s original description of the oak contains this comment: “lobes gradually lessening in size so as to resemble a pagoda.”

palles'cens: becoming pale, fading.

pal'lida/pal'lidum/pal'lidus: ashen, pale, wan, from Latin pallidus, "pale or yellow(ish)."

palma'ta/palma'tum: lobed like a hand.

palm'eri: named for self-taught botanist, professional plant collector and amateur zoologist, archaeologist and ethnologist

Edward Palmer (1829-1911). Born in England, he "emigrated to the United States [in 1849] at the age of eighteen. He developed an interest in natural history collecting under the tutelage of Dr. Jared Kirtland and got his first major opportunity to collect when he was appointed to Captain Page's Water Witch expedition to Paraguay as hospital steward and botanical collector in 1853. After the Paraguay expedition he went to England to visit his mother, got married on March 29, 1856, and came back to the U.S. He studied medicine for a few months in Cleveland; then he lived in Kansas, Colorado, and for a

few months, California, where he worked on the Geological Survey of California, collecting marine invertebrates. During the Civil War, he did medical work in army outposts in the southwest for a while after the war. He managed to make natural history collections while working for the army. The rest of his life was mostly taken up with making archaeological, zoological and botanical collections for a variety of patrons, primarily in the southwestern U.S. and Mexico. He is best known for his botanical collections, which are said to number over 100,000 specimens. He made numerous botanical collecting trips to Mexico from 1878 to 1910. Rogers McVaugh describes Palmer's botanical specimens as "exceptionally well documented for his time," a trait which was obscured by the fact that his field notes were not distributed with his plants." (From a website of the Library of the Gray Herbarium). Palmer was not a professional botanist or biologist. He made a living wandering throughout the western states and Mexico, collecting plant and animal specimens of all kinds that he sold to museums in the United States and England. He also collected specimens in Florida and Baja. Other better known naturalists like Spencer Baird, George Engelmann, John Torrey, and Charles Parry often hired him to collect for them. Funded by the Peabody Museum at Harvard in 1880, he investigated and retrieved objects from burial caves known to be in the region of Coahuila, Mexico. In 1890 while exploring the southernmost coast of Sonora, he was afflicted by spells of "intermittent fever" (which he probably contracted on the coast, for the coastal swamps supported hordes of blood-sucking insects), but he still managed to add 124 specimens to his collection. He was the first to call attention to the boll weevil that ultimately caused $5 billion in damage to the American South's cotton crops 50 years later. He worked for the Department of Agriculture, the Smithsonian Institute and the Army Medical Museum. It has been stated repeatedly that in 1891 he collected plants on and even led an expedition exploring the flora and fauna of California and Death Valley. This expedition in fact was organized and initially led by Dr. C. Hart Merriam and sent out by the U. S. Department of Agriculture under the subsequent leadership of Theodore Sherman Palmer (no apparent relationship) to make a biological survey of the region of Death Valley, California, an expedition on which Frederick Vernon Coville, first Curator of the U.S. National Herbarium, was the botanist. Undoubtedly there was confusion regarding the name Palmer because it appears that Edward Palmer was in Mexico in 1891.  He suffered personal and professional tragedies such as the death of his young bride from yellow fever, and the losses of several of his collections.  After his death his field notes sat neglected on a shelf for more than fifty years.  He did however have two hundred species named for him, and Professor Asa Gray named a genus, Palmerella, in his honor. The genus Malperia was apparently also named for him, according to Umberto Quattrocchi. He was perhaps one of the most productive amateur botanists ever to collect a plant. (Amaranthus palmeri)

Xpalmeria'na: a hybrid oak species with parents Q. falcata and Q. imbricata, named for Ernest Jesse Palmer (1875-1962),

		plant collector, botanical taxonomist and naturalist. He was born in Leicester, England, and moved with his parents to the United States in 1878, where they first lived in Warrensburg, Missouri, and then [in 1891] moved to Webb City, Missouri. A bio by Nancy Wallace Brewer on the Find-a-Grave website says: “Although self-educated in the fields of botany, geology, and archaeology, Mr. Palmer acquired a wide reputation in the natural sciences. In 1913 he was appointed to the staff of the Missouri Botanical Garden in St. Louis, and in 1921 he became a research taxonomic botanist with the Arnold Arboretum

of Harvard University. Mr. Palmer devoted a great deal of his life to studying the flora of his native Missouri. Although specializing primarily in the woody plants, he became a recognized authority of all the state's flora. The Palmer Hawthorn (Crataegus palmeri), a species native to southwestern Missouri, was discovered by Palmer and bears his name. As a member of the George Washington Carver Memorial Committee he marked the nature trail, identifying the flora, and prepared a collection and explanatory booklet for the George Washington Carver Museum at Diamond, Missouri. Mr. Palmer's extensive collection of geological, archaeological and botanical specimens and artifacts is highly valued and includes a number of rare fossils of Missouri now on display at the Smithsonian Institute in Washington, D. C. An unusually fine herbarium containing 20,000 specimens and a large portion of his various collections were willed to the University of Missouri. Through the generosity of Mr. Palmer his letters and papers covering a thirty year period are deposited in the State Historical Society collections. Mr. Palmer published many scientific pamphlets and treatises, and collaborated with other scientists in writing several books. He also published a volume of poetry, Gathering Leaves, Green, Gold, and Sere in 1958. He was a fellow of the American Association for Advancement of Science, a member of the American Society of Plant Taxonomists, the Botanical Society of America, the American Fern Society, the St. Louis Academy of Science, the New England Botanical Club, the Boston Mineral Club, the Missouri Archaeological Society, and the State Historical Society of Missouri.” He had been interested in the natural world from a young age, and the town of Webb City, Missouri, was a lead and zinc mining boom town when the Palmer family moved there. Palmer concentrated his natural history interest on the Carboniferous age marine fossils which were abundant in the mine tailing piles. In 1913 he began collecting professionally for the Missouri Botanical Garden. Charles Sprague Sargent, founding director of the Arnold Arboretum, was the person mainly responsible for directing Palmer’s career to botany. Palmer and Sargent first became aware of each other through the botanist Benjamin Franklin Bush. Bush had started collecting plants for Sargent and the Arnold Arboretum around 1899, after several years of doing the same for the Missouri Botanical Garden. Sargent offered him a formal post at the Arnold Arboretum in 1921 and he moved to Boston. During his career he collected in almost every state of the United States. He was married at the age of 55 to bacteriologist Elizabeth McDougall Palmer and had three children. He retired in 1948 and returned with his wife and their family to Webb City, Missouri where he died. (Photo credit: "Ernest Jesse Palmer and Charles Sprague Sargent: A Serendipitous Relationship" by Theodore Palmer, Arnoldia 75/2, 2017)

paludige'na: marsh-born, having something to do with originating from or growing in marshes or swamps, from Latin paludis, "a marsh," and genitus, "to beget." The species Poa paludigena is called bog or marsh bluegrass.

palus'tris: growing in marshes, from Latin palus, "marsh."

Pan'ax: ginseng. William Stearn provides this: "from Greek panakes, "all healing, a panacea," in allusion to the high value placed on it by the Chinese for aphrodisiacal and medicinal purposes. American ginseng (Panax quinquefolius) is very closely related to the Asiatic ginseng (Panax ginseng) from which the English name derives. The genus Panax was published by Carl Linnaeus in 1753.

pandura'ta: from the Latin pandura, a three-stringed musical instrument supposedly invented by Pan, and forme, indicating shape or resemblance, thus "fiddle-shaped," most likely referring to the leaf shape. Common names for Ipomoea pandurata include man of the earth, wild potato vine, manroot, wild sweet potato, and wild rhubarb.

panic'ea: like millet grain, Panicum.

panico'ides: resembling genus Panicum.

panicula'ta/panicula'tum: the species epithet paniculatum refers to the arrangement of flowers in terminal panicles, and derives from the Latin panicula, "tuft, swelling," and -atus, "having."

Pan'icum: from the classical Latin name panus that was used for foxtail millet (Setaria italica or Panicum italicum), meaning "an ear of millet," also according to Jaeger's Source-Book of Biological Names and Terms a word meaning a swelling, of uncertain application. An additional although not unrelated derivation is that the name Panicum comes from the Latin panis, meaning "bread," perhaps because bread was made from millet, and perhaps the use of the term meaning "swelling" has to do with bread rising as it bakes. The genus Panicum was published by Carl Linnaeus in 1753 and is called panic grass or witch grass.

Papa'ver: the classical Latin name for the poppy, derived from papa, "pap or thick milk," and one source says "in the old times they put the petals, or the juice or the seeds into the food for favouring the sleep of the young children." FNA says that the name Papaver is the "classical Latin name for poppy perhaps from Greek papa (pap), alluding to the thick, sometimes milky sap." The genus Papaver was published in 1753 by Carl Linnaeus and is called poppy.

papyrif'era: paper-bearing, from Latin papȳrus, "paper,"and -fer or -fera, "bearing, from fero, "to bear." Betula papyrifera is called paper birch, Broussonetia papyrifera is called paper mulberry, and Tetrapanax payrifer is called rice-paper plant, and in all three cases the name refers to some quality of the bark being used for some paper or paper-like purpose.

paradox'a: paradoxical, contrary to expectation.

Para'pholis: from the Greek para, "near, beside, near to," and the genus Pholiurus, which derives from pholis or pholidos, "scale, horny scale," thus apparentlly meaning a nearly related genus to genus Pholiurus. Gledhill says it means irregular scales, and another source says "alternatively, from the Greek para, "beside," and pholis, "scale," alluding to the resemblance of the glumes to the scales of a snake. This seems an unlikely derivation, and what is more likely is that it alludes to the collateral glumes. The genus Parapholis was published by Charles Edward Hubbard in 1946.

Parathelyp'teris: for Greek para, "beside, near," and genus Thelypteris. The genus Parathelypteris was originally published in a different genus by Hiroshi Ito but was then moved to Thelyperidaceae by Ren Chang Ching in 1963.

Parietar'ia: derives from the Latin parietarius, "of walls," which descends from Greek paries, "a wall," where the plant likes to grow, as Pliny knew when he described it. The genus Parietaria was published by Carl Linnaeus in 1753 and is called pellitory.

par'keri: named for Charles F. Parker (1820-1883), Curator of the Academy of Natural Sciences of Philadelphia, where he was born. His mother died when he was an infant and his father was able to give him only a modest education, so he apprenticed as a bookbinder which was his father’s profession. He remained in Philadelphis until about the age of 22 when he went to Boston to undertake the same work.  In 1851 he left Boston and moved with his wife to Loeminster where he continued bookbinding and opened a bookstore. The business was not as successful as he had hoped and within a couple of years he left it and moved to Camden, New Jersey, where he remained for the rest of his life. During the early part of his life he did not evince a great interest in natural history, but fortuitously he was a frequent companion of the well-known naturalist Constantine Samuel Rafinesque who was a boarder in the same house, and it may be presumed that this was the impetus that pushed Parker in that direction. Without having had any training or exposure to the subject, he became interested in conchology, and then in butterflies and beetles. He applied for membership in the Entomological Society of Philadelphia and was accepted in 1861. This was the beginning of a new life for him and he soon became enamored of botany. Apparently having been largely unaffected by the events of the 1860s, he joined others in collecting trips and undertook the same on his own with a great zeal. He was elected to the Academy in 1865, and for seven years devoted his efforts to the conchological collection, creating a systematic arrangement and preparing and mounting some 100,000 specimens. This was the greatest volunteer work ever done in the Academy. In 1874 he was elected one of the Curators and was soon induced to accept employment which necessitated partially giving up the bookbinding business. He progressed further and further into botanical fields and made the aquaintance of Coe F. Austin, the noted cryptogamic botanist, with whom he collected numerous examples of the flora of New Jersey. A preliminary catalog was compiled by Nathaniel Lord Britton in which Parker’s name was frequently mentioned, and it was printed under the auspices of the Geological Survey of New Jersey. He soon became the principal authority on the flora of the Pine Barrens. The tremendous amount of work he carried on for the Academy nevertheless took its toll on him, and in 1883 his health rapidly gave way and a paralysis of the brain terminated his life at the age of only 63. He was a born naturalist with a quick eye, good judgement and an excellent memory. Had he been able to avail himself of a proper education while younger, he no doubt would have become one of the leading scientists of his day, and yet the accomplishment he made were the equivalent of many of those far better educated workers in the field. (Information extracted from an obituary notice by Isaac C. Martindale, his friend and colleague for a quarter century,  in the Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 35, 1883.)  

parlin'ii: named for John Crawford Parlin (1863-1948), American educator and botanist born in Maine who discovered and

recognized the uniqueness of the species named for him, Antennaria parlinii. He was born in Paris, Maine, and as a youth lived in Paris and surrounding towns, and was educated in the town schools.  He began teaching in the town of Woodstock and later taught in North Berwick, Albion, Norridgewock, Freedom, Hartford, Rumford and Canton. He also conducted five summer sessions at the Washington State Normal School at Machias, Maine, where one of his subjects was botany. During his teaching career he was President of the Teachers’ Association in Somerset and Waldo Counties and served on the

Executive Board of the Maine Teachers’ Association. He retired in 1920 after 48 years as a teacher and moved to Canton Point, Maine, where he spent many years pursuing his botanical work. In March, 1936, a spring flood swept through his home and destroyed his collection of specimens which had been gathered so assiduously. Some time after that he moed to Buckfield and continued his botanical explorations. His major iinterest was in the study of the flowering plants and ferns of his native state. After discovering a previously undiscovered Antennaria plant led him to more intensive study of that genus. During the latter part of his life he devoted the majority of his time to mosses and lichens. He carried on an extensive correspondence with botanical authorities both in the United States and Europe.  He was a member of the Maine Historical Society, the Portland Society of Natural History, the Stanton Bird Club of Lewiston-Auburn, the Dullivant Moss Society, the New England Botanical Club,and the Josselyn Botanical Society of Maine. The year before his death he received an honorary degree of Master of Science from the University of Maine in recognition of his outstanding work. He died at Canton Point, Maine, at the home of his daughter. He was married for 59 years and had two children. (The majority of this information was extracted from an obituary by Ralph C. Bean in Rhodora, the Journal of the New England Botanical Club. Photo credit Ancestry.com)

Parnas'sia: named for Mt. Parnassus of Greece, of uncertain application, except that Linnaeus liked to use names from Greek and Roman history and mythology. The genus Parnassia was published by Carl Linnaeus in 1753 and is called grass of parnassus or just parnassia.

Parony'chia: from the Greek paronychia, "a whitlow," which is a painful infection of the finger, especially beneath the nail, derived in turn from para, "near," and onyx, "nail." One of the common names for Paronychia is whitlow-wort, an herb thought to be a cure for whitlow. The genus Paronychia was published by Philip Miller in 1754 and is called whitlow-wort or nailwort.

Parthen'ium: one source says this epithet comes from the classical Greek name parthenion for a plant now known as Tanacetum parthenium, but a Missouri Botanical Garden website says that "The genus name Parthenium comes from the Greek [word parthenos] meaning 'virgin,' in reference to the fertile ray florets and infertile disk florets of species in this genus." The genus Parthenium was published in 1753 by Carl Linnaeus and is called wild quinine.

Parthenocis'sus: from the Greek parthenos, "a virgin," and kissos, "ivy," a genus whose common name is woodbine or virginia creeper, Virginia having been named for England's virgin queen Elizabeth I. The genus Parthenocissus was published by Jules Émile Planchon in 1887 and is called virginia-creeper and woodbine.

parviflor'a/parviflor'um/parviflor'us: from the Greek parvus, "small," and flora, "flower," hence "small-flowered."

parvifo'lia: small-leaved.

par'vula: somewhat small.

Pas'palum: from the Greek paspalos for "millet." The genus Paspalum was published Carl Linnaeus by in 1759 and is called paspalum, crowngrass or beadgrass.

Passiflor'a: from the Latin passio, "passion," and flos, "flower," hence passion flower. The name was given because the plant parts seemed to represent aspects of Christ: the corona was the crown of thorns, the five stamens were the five wounds, the three styles three nails, and the ten petal-like parts the ten faithful apostles. The genus Passiflora was published by Carl Linnaeus in 1753 and is called passionflower.

Pastina'ca: uncertain derivation. Wikipedia says "The name may be derived from the Latin word pastino (or pastinare), meaning "to prepare the ground for planting of the vine" (or more simply, "to dig") or the Latin word pastus, meaning "food", liberally translated as "Earth-food." Gledhill says: "Earth-food, from a trench in the ground (formerly for carrot or parsnip), from pastinare, "to dig." Other sources say "From Latin pastinaca ("parsnip, carrot"), from pastinum ("two-pronged fork"); related to pastinare ("to dig up the ground").

patagon'ica: of or from Patagonia, a region in Chile and Argentina.

pat'ens: spreading, from Latin patina, "pan or broad, shallow dish," from the Greek patane, "plate, dish," in turn from the Proto-Indo-European root pete-, "to spread."

Pat'is: an anagram of the closely related Stipa, assigned by Japanese botanist Jisaburo Ohwi (1905-1977) in 1942. The genus goes by the common name ricegrass, a name which has also been used in the genera Oryzopsis, Eriocoma and Achnatherum.

pat'ula/pat'ulum: somewhat spreading.

pauci-: few, from Latin paucus, "few."

pauciflor'a/pauciflor'um/pauciflor'us: few-flowered.

paucifo'lia: with little foliage, literally "few-leaved."

Paulown'ia: named for Anna Pavlovna Romanova (von Holstein Gottorp) (1795-1865), queen consort to King William II

of the Netherlands from 1840 to 1849, and daughter of Tsar Paul I of Russia. The genus was originally spelled Pavlovnia. She was born at Gatchina Palace in St. Petersburg the eight child of the Tsar. Her father became Tsar a year after she was born and was assassinated in 1801. Anna’s brother Alexander became Tsar. She was raised by her mother and spent her early years at the Romanov’s summer residence, Tsarskoye Selo. She was tutored by the Swiss governess Louise de Sybourg and received a broad education, including foreign languages (Russian, German and French) and mathematics. She was

good at handicrafts and painting, and had a good relationship with Alexander, but was closest to her younger brother Nicholas who became Tsar in 1825 upon Alexander’s death. Her hand in marriage was requested first by Napoleon I in 1809 and then by others in French and British royalty before she finally accepted the Prince of Orange, who later became King William II of the Netherlands. During her lifetime she was only rarely involved in political affairs. Her marriage was stormy and she was not popular with the public despite having founded over fifty orphanages and being involved in various charities such as the founding of hospitals. She was a strong Russian patriot throughout her life and maintained frequent contact with her family. It has been said of her that she remained a Russian Grand Duchess more than she ever became Queen of the Netherlands. She had a Russian Orthodox private chapel in her private quarters, and had her own priest and Russian choir boys to serve her. She kept her Orthodox religion and continued to live in accordance with Russian custom (albeit in her case the French influenced Russian aristocratic version) and sometimes appeared in Russian national costume. Her husband died with large debts in 1849 and she left the royal palace, retired from court life and lived a private life. I can find no particular reason why she should have been honored with this botanical name. The genus Paulownia was published by the German botanists Philipp Franz Siebold and  Joseph Gerhard Zuccarini in 1835 and is called princess tree, empress tree or just paulownia.

pauperc'ula: poor, of poor appearance, diminutive of pauper, "providing little."

Paxisti'ma: from the Greek pachys or pachos, "thick, stout," and stigma, "stigma," alluding to the slightly enlarged stigma. The genus Paxistima was published by Constantine Samuel Rafinesque in 1838 and is called mountain-lover.

pectina'cea: comb-like.

pectina'ta/pectina'tum: comb-like, from Greek peko, "to comb."

peda'ta: like a bird's foot, with divisions radiating from a single point.

pedemonta'num: I thought at first that this name referred to the Piedmont region of Virginia, but the taxa Galium pedemontanum is infrequent in the Piedmont. The Latin adjective pedemontanum means "at the foot of the mountains," so this is a more likely derivation.

pedicular'ia: probably the same as pedicularis, from the Latin pediculus meaning "louse," referring to the old English belief that when cattle grazed on these plants, they became infested with lice. The common head and body louse that typically infect human beings is called Pediculus humanus.

Pedicular'is: from the Latin pediculus meaning "louse," referring to the old English belief that when cattle grazed on these plants, they became infested with lice. The common head and body louse that typically infect human beings is called Pediculus humanus. The genus Pedicularis was published by Carl Linnaeus in 1753 and is called wood-bettony or lousewort.

Pediomel'um: from the Greek pedion, "a plain or level country," and melon, apple, thus "plains-apple," a translation of the French vernacular name pomme-de-prairie. The genus Pediomelum was published by Per xel Rydberg in 1919 and is called buckroot or prairie-turnip.

peduncula'ta/peduncula'tum: with a distinct stalk, referring to the prominent flower stems, from the Latin pedunculatus, "peduncle, a flower stem/stalk."

pel'lita: skinned, from the Latin pellis, "skin or hide," thus meaning covered with skin or hide, or having skin or hide.

petaloid'ea: petal-like.

peda'ta/peda'tum: like a bird's foot, with divisions radiating from a single point.

pedatifi'da: same as pedata.

Pellae'a: from the Greek pellaios, "dark," possibly alluding to the stalks of this fern which are generally dark. The genus Pellaea was published by Johann Heinrich Friedrich Link in 1841.

pelocar'pus: Gledhill says "mud-fruit, fruit of the mud," from Greek pelos, "clay, mud." The species Juncus pelocarpus is commonly called brown-fruited rush.

Peltan'dra: from the Greek pelte, "a shield, target," and aner or andros, "stamen, man," hence "hidden or shielded anthers or stamens." The genus Peltandra was published by Constantine Samuel Rafinesque in 1819 and is called arrow-arum.

pelta'ta/pelta'tum: shield-shaped, attached on the lower surface away from and not at the margin.

pen'dula/pen'dulus: hanging, pendulous.

Pennise'tum: from the Latin penna, "feather," and seta, "a bristle," thus literally, "feather-bristled," because some species have plumose or feathery bristles. The genus Pennisetum was published by Louis Claude Marie Richard in 1805 and is called fountain grass or pearl millet.

pennsylva'nica/pensilva'nicus/pensylva'nica/pensylva'nicum: of or from Pennsylvania.

Pen'stemon: the usual derivation for this name published in many sources including Stearn's Dictionary of Plant Names for Gardeners and Flora of North America is from the Greek penta, "five," and stemon, "stamen," for the fifth stamen, referring to the staminode, and alluding to the fact that it has five stamens, but this appears to be not exactly the case. One piece of evidence that this might have been true is that the genus name was spelled at one time, apparently incorrectly by Linnaeus, Pentstemon, which would correspond with the root penta. But John Mitchell's original publication in 1748 had the spelling that we are now familiar with, Penstemon, and a number of people such as Francis Whittier Pennell, Walter Fertig and others have opined that the “pen” in Penstemon comes not from penta ("five") but from the Latin paene meaning “nearly” or “almost”, while stemon comes from the Greek for “thread.” Fertig in an online USDA Forest Service article on Rydberg's penstemon says “Nearly a thread is a reference to the staminode, which is almost a functional stamen." So both derivations have to do with the stamens, and particularly the fifth stamen, but the root words are different. A well-presented summary of how this etymology came to be is provided in Al Schneider's excellent website Wildflowers, Ferns and Trees of Colorado, New Mexico, Arizona and Utah and is presented here with only minor adustments: “From his plant collections in Virginia, the well-known botanist (and cartographer, zoologist and physiologist) Dr. John Mitchell described and named a new species which he placed in a new genus, Penstemon. In 1748 he published the new species and genus. A few years later Linnaeus described this new plant in his famous 1753 Species Plantarum. However, Linnaeus renamed Mitchell's new plant Chelone pentstemon, placing the plant in an already existing genus, changing Mitchell's spelling of Penstemon to pentstemon, and making pentstemon the specific epithet, not the genus. The rules of the modern International Code of Botanical Nomenclature indicate that no plant names or descriptions are valid if they were published before 1753, the date of Linnaeus' Species Plantarum. Mitchell published the genus name Penstemon in 1748, so it is not valid. Since Linnaeus placed the plant Mitchell discovered in the genus Chelone, there is no publication of the genus name Penstemon in Linnaeus' 1753 Species Plantarum. In his 1762 Icones Plantarum (Illustrations of Plants, page 2), Casimir Schmidel published a description of the Penstemon genus [in 1763], and this is the earliest publication of the new genus name. Schmidel is now accepted as the author of the Penstemon genus name. Schmidel did not, however, describe a particular species in this genus. That description was finally written by the renowned British gardener, William Aiton, "Gardener to his Majesty" from 1759 to 1793. In the King's Gardens Aiton grew plants from the seeds of Penstemon plants collected by Mitchell. In his three volume 1789 Catalogue of the Plants Cultivated in the Royal Botanic Garden at Kew,  Aiton described these plants and named the species, Pentstemon laevigata. This species is the accepted type specimen of the genus. The accepted spelling of the name is now Penstemon laevigatus. Most botanical floras indicate that the word Penstemon is derived from the Greek pente, "five," and stemon, "thread.”  It is stated that Penstemons are so named to point out that they have five stamens (thread-like structures) and/or to draw attention to one of the five stamens, the one that is sterile and distinctly different from the others. This derivation would be supported by Linnaeus' spelling of the genus name, Pentstemon.  However, the genus name was not spelled Pentstemon by Mitchell or Schmidel, and it is not now the accepted spelling. A more accurate etymology of the name Penstemon is therefore the one given by the prestigious Intermountain Flora: pen (or paene) is Latin for "nearly," and stemon, for "thread.”   The genus name thus means "nearly a thread", i.e., that there is one structure that is nearly a stamen.” The genus is commonly called beard-tongue or just penstemon.

pentacar'pos: could not find this listed anywhere with a derivation or meaning, but it is presumably from penta, "five," and karpos, "fruit," and the description of Kosteletzkya pentacarpos includes the fact that it is 5-locular so that it probably where the name comes from.

pentago'na: from Greek pente, five, and horos, limit or landmark, alluding to 5-merous flower overlapping bases of the sepal lobes.

pentan'dra: with five stamens, from the Greek pente meaning five and andro meaning stamen.

Penthor'um: Flora of North America says from Greek pente, "five," and horos, "limit or landmark," alluding to the 5-merous flower, but Gledhill says Penthorum means "five-column" and refers to the beaks on the fruit. The genus Penthorum was published by Carl Linnaeus in 1753 and is called ditch stonecrop.

peplo'ides: means "resembling Peplis (now Lythrum) portula" and describes the appearance of the plant when it grows on exposed mud, rather than under water.

pep'lus: pep'lus: this is one that I'm still puzzling over. One source has peplum as a garment worn by women in ancient Greece, which was cloth caught at the shoulders and draped in folds to the waist, and another gives peplis as a name used by Dioscorides as a Mediterranean coastal spurge and peplus as a name he used for the northern equivalent of peplis.

pe'po: Gledhill says "sun-cooked, opening to become edible, fully ripened." Derived from the Latin, literally meaning ‘pumpkin’, from Greek pepōn, "ripe gourd or large melon," from peptein, "to ripen."

per-: one of its Latin meanings is "all over, during or throughout," and another is "well, very much or completely."

peramoe'na: very pleasing, alluding to its very beautiful flowers.

perangusta'tus: angustata means narrow or narrowed, and applying the Latin prefix per which has the intensive meaning of well, very much or completely, we have very or completely narrow.

peregri'na: strange, foreign, exotic, immigrant, wandering or straggling in growth.

peren'nans: same as perennis.

peren'ne/peren'nis: perennial, from Latin perennis, "everlasting," from the Latin suffix per-, "all over, during, throughout," and annus, "annual."

perfolia'ta/perfolia'tum/perfolia'tus: perfoliate, refers to a leaf which has its margins entirely surrounding the stem in such a fashion that the stem seems to pass through the leaf.

Peril'la: Stearn says: "Derivation obscure; probably a diminutive of Latin pera, "bag, wallet, pocket" in allusion to the fruiting calyx." This is echoed by Umberto Quattrocchi who mentions that the Greek pera means "a pouch." But Gledhill says: "Thought to be from a Hindu vernacular name," and the Merriam-Webster Dictionary states: "The name Perilla is known in Latin literature from poems addressed by Ovid to a real or pseudonymous "Perilla," though inscriptional evidence for such a given name in Rome is apparently lacking." The genus Perilla was published by Carl Linnaeus in 1764 and is called perilla or beefsteak plant.

perpus'illa: exceptionally small or weak, from per-, used to make adjectives or verbs that are "very" something, and pusillus, "very little, very small, tiny," or sometimes in a contemptuous sense, "puny, petty, insignificant."

Per'sea: a name used by Theophrastus from the Greek persea for a tree (Cordia myxa) growing in Egypt and Persia. The genus Persea was published by Philip Miller in 1754 and is called bay.

per'sica: of or from Persia.

Persicar'ia: the medieval name of a knotweed, from persica, "peach," alluding to the shape of the leaves. The genus Persicaria was published by Philip Miller in 1754 and is called smartweed, lady's thumb, water-pepper, tearthumb and jumpseed.

persicifo'lia: with leaves like a peach tree (Prunus persica).

petiolar'is: with conspicuous petioles, not sessile.

petiola'ta/petiola'tum: furnished with a leaf stalk, having a petiole, not sessile.

Petrorha'gia: from the Greek petros, "rock," and rhagas, "a chink or break" from rhegnymi, "to break asunder," thus meaning "rock fissure" in reference to the habitat of some species. The genus Petrorhagia was published by Johann Heinrich Friedrich Link in 1831 and is called pink.

pe'xa: having a surface with an apparent nap, combed.

Phace'lia: based on the Greek phakelos, meaning "cluster," and alluding to the densely crowded flower spikes of most species. of the genus. The genus Phacelia is called phacelia or scorpion-weed and was published by Antoine Laurent de Jussieu in 1789.

phaenopy'rum: Gledhill says "with shining grains." The Virginia Tech Dendrology website says this name derives from the Greek phaeno, "visible," and Pyrus, "pear," with uncertain application.

Phalar'is: an ancient Greek name used by Dioscorides for a kind of grass with shiny spikelets, according to Umberto Quattrocchi from phalaros, "having a patch of white, crested," and/or phalos, "shining, bright, white." The genus Phalaris was published by Carl Linnaeus in 1753 and is called canary grass.

Phanopy'rum: from the Greek phanos, "bright, light, a torch," and pyros, "wheat," alluding to the appearance of the grain. The genus Phanopyrum was published by George Valentine Nash in 1903 and is called phanopyrum or savannah panic grass.

Phaseo'lus: from the Greek phaselos, "a little boat or light vessel," referring to its similarity to a bean pod, this name became the Latin phaseolus used for a kind of bean. The genus Phaseolus was published by Carl Linnaeus in 1753 and is called wild bean.

Phegop'teris: from Greek phegos, "beech," and pteris, "fern," this species is called the beech fern. The genus Phegopteris was published in 1852 by Karl Presl.

phel'los: corky, from Greek phellos for "cork."

Phemeran'thus: derived from the Greek words εφήμερος (ephemeros), meaning "living for one day," and ἄνθος (anthos), meaning "flower." The Online Flora of Wisconsin says: "possibly from Greek ephemeron, "a dayfly,” and anthos, "a flower,” alluding to its short blooming time." The genus Phemeranthus was published by Constantine Samuel Rafinesque in 1814. and is called flameflower or rock-pink.

philadel'phica/philadel'phicum/philadel'phicus: of or from Philadelpha. The species Panicum philadelphicum is called Philadelphia panic grass.

Philadel'phus: a Greek-derived name after Ptolemy II Philadelphus (308-246 BC), Macedonian Greek King of Egypt from

about 283 until his death in 246 BC. He was born on the Isle of Kos (Cos), the son of one of Alexander the Great’s generals, Ptolemy I Soter, who founded the Ptolemaic Kingdom, a Hellenistic kingdom based in ancient Egypt and ruled by the Ptolemaic dynasty, which started with his accession after the death of Alexander the Great in 323 BC and ended with the death of Cleopatra and the Roman conquest in 30 BC. His reign was significant in many ways. He promoted the Museum and the great Library of Alexandria, he developed agriculture and commerce, engaged in skillful diplomacy, and made

Alexandria a leading centre of the arts and sciences. Dynastic strife resulted in the banishment of his first wife, Arsinoe I, daughter of King Lysimachus of Thrace, following which he married his sister Arsinoe II, widow of Lysimachus. He was the first Pharoah to marry a full sister, but the tradition became standard for the Ptolemies. He began his reign as co-regent with his father in 285 BC and was sole ruler in 283/282. Although he was successful in prosecuting the so-called First Syrian War against Antiochus I, the Seleucid king who was trying to expand his empire's holdings in Syria and Anatolia, the Second Syrian War against Antiochus II did not go so well, and a substantial naval defeat lessened Ptolemy’s power. The war ended upon the marriage of Antiochus to Ptolemy’s daughter, and both men died in 246, the former possibly poisoned by his previous wife Laodice. The material and literary splendour of the Alexandrian court was at its height under Ptolemy II. Pomp and splendor flourished. He had exotic animals of far off lands sent to Alexandria, and staged a procession in Alexandria in honor of Dionysus led by 24 chariots drawn by elephants and a procession of lions, leopards, panthers, camels, antelopes, wild asses, ostriches, a bear, a giraffe and a rhinoceros. According to scholars, most of the animals were in pairs - as many as eight pairs of ostriches - and although the ordinary chariots were likely led by a single elephant, others which carried a 7-foot-tall golden statue may have been led by four. Ptolemy was very interested in both Greek and Egyptian religion, and and spent large sums erecting temples. Ptolemy undertook a great deal of building work throughout Egypt. He enlarged the shrine of Renenutet at Medinet Madi, built a gate between the temple of Imhotep and the temple of Isis on Philae, made additions to the temples of Elephantine and Thebes, left his mark on the temple of Sobek at Medinet el-Fayyum and built a new main temple at Koptos. He also completed the Great Lighthouse of Alexandria (also known as Pharos) and ordered the construction of a number of cities along the red sea coast (along with numerous temples and canals) which helped to strengthen trade links with the Mediterranean and boost the Egyptian economy. Pliny the Elder also reported that he established trade link with India, probably with the emperor Ashoka as he is mentioned in the Edicts of Ashoka. He reformed both the tax systen and the system of coinage. He deified both his parents and his sister-wife. He was a generous patron of poets, artists and scholars. He also financed the Museum, a research centre where learning included philosophy, literature, mathematics and the natural sciences. Ptolemy reformed the judiciary and promoted royal law above Egyptian and Greek law. He created three distinct courts: the Chrematistai was the royal court and heard cases on an ad hoc basis; the Dikasteria heard cases involving Greek speaking parties; and Laokritai heard cases involving parties who spoke Egyptian and was overseen by Egyptian priests. Informal disputes were still handled outside the courts under Egyptian law with no state interference. Thus while there was a clear aim to centralise control of the legal system, Ptolemy also respected local traditions and much of the reform may in fact have been a codification of the existing situation. He died in Alexandria and was succeeded by his very capable son, Ptolemy III Euergetes. The genus Philadelphus was published by Carl Linnaeus in 1753 and is called mock orange.

philoxero'ides: I can't find anything certain about this epithet, but philos- means "loving, fond of, having an affinity for," and xeroides appears to relate to dryness, so perhaps this means something like "loving dry areas"?

Phle'um: from the Greek phleos, an ancient name for a kind of swamp-growing grass. The genus Phleum was published by Carl Linnaeus in 1753 and is called timothy.

phlogifo'lium: Stearn says "with leaves like Phlox," but Gledhill says "red-leaved." Jaeger's source book explains about the root phlog: from "Greek phlox, genitive form of phlogos, "a flame," hence reddish.

phlomo'ides:resembling genus Phlomis.

Phlox: from the Greek phlox, "flame," ancient name of Lychnis of the Caryophyllaceae. The genus Phlox was published by Carl Linnaeus in 1753 and is called phlox.

phoenicola'sius: with red or purple hairs. from the Latin phoenicus, meaning red. The biennial stems called canes from the perennial root system have red glandular hairs.

Phoraden'dron: from the Greek phor, "a thief," and dendron, "tree," hence "tree thief" because it draws nourishment from its host tree. The genus Phoradendron was published by Thomas Nuttall in 1848 and is called mistletoe.

Phragmi'tes: from the Greek phragma, "a fence or screen, hedge," hence growing in hedges. The genus Phragmites was published by Michel Adanson in 1763 and is called common reed.

Phyllan'thus: from Greek phyllon, "a leaf," and anthos, "a flower," alluding to the apparent production of flowers on leaves (actually plagiotropic branchlets) of some species. The genus Phyllanthus was published by Carl Linnaeus in 1753 and is called leafflower.

Phry'ma: Flora of North America, SEINet, Gledhill and Stearn all draw a blank on this one. The Flora of Wisconsin website says: "name erroneously given by Bauhin as the Latin equivalent of the Greek Phyrama, an inferior grade of the resin of the metops 'tree,' a north African umbellifer. Literally, something mixed and kneaded, dough." The website of the Eloise Butler Wildflower Garden in Minneapolis, which claims to be the oldest public wildflower garden in the United States, simply says: "The genus name Phryma has a contested background derivation but is taken today to refer to the Lopseeds." The genus Phryma was published by Carl Linnaeus in 1753 and is called lopseed.

Phy'la: from the Greek phyle, "tribe," probably from the flowers being tightly clustered in heads. The genus Phyla was published by João de Loureiro in 1790 and it is called frogfruit.

Phyllosta'chys: from the Greek phyllon, "leaf," and stachys, "a spike." The genus Phyllostachys was published by Philipp Franz Siebold and Joseph Gerhard Zuccarini in 1843 and is called bamboo.

Phy'salis: from the Greek physalis, "a bladder or bubble," because of the inflated calyx. The genus Physalis was published by Carl Linnaeus in 1753 and is called ground-cherry.

physalo'des: bladder-like, from the Greek physo, meaning "bladdery," and alluding to the inflated calyx.

Physar'ia: from the Greek phusa or physa, "bellows" because of the inflated pod. The genus Physaria was published by Asa Gray in 1849.

Physocar'pus: from the Greek phusa or physa, "bladder, a pair of bellows" and karpos, "fruit," thus "bladdery fruit." The genus Physocarpus was published by Constantine Samuel Rafinesque in 1836 and is called ninebark.

physorhyn'cha: from Greek phusa or physa, "bladder, a pair of bellows" and rhynchos, "horn, beak, snout." The species Carex physorhyncha is called bellows-beak sedge.

Physoste'gia: literally means "inflated cover," from the Greek physa, "bladder," and stege, "roof covering," alluding to the fruits that are covered by an inflated calyx. The genus Physostegia was published by George Bentham in 1829 and is called obedient-plant or false dragonhead.

Phytolac'ca: from the Greek phyton, "plant," and Latin lacca, "crimson lake," because of the color in the berries. The genus Phytolacca was published by Carl Linnaeus in 1753 and is called pokeweed.