Plant Families with Sole Members

Aristotle

As far back as Aristotle* and perhaps beyond, the scientifically-inclined nerds of ancient days would cubbyhole plants and animals as a means to better understand them. In botany, more recently, plant families such as Rosaceae, Pinaceae and Leitneriaceae all end in aceae, and that is the Latin feminine plural of aceus meaning "relating to, belonging to, having the nature of, or resembling." As with potātoes-potătoes, tomātoes-tomătoes, the pronunciation of aceae varies, and not wanting to humor anyone I use the suffix in written communication but it is not in my verbal diction.

*I recommend The Lagoon – How Aristotle Invented Science by Armand Marie Leroi.

Leitneria floridana

Leitneria floridana ("corkwood") is the sole member of Leitneriaceae*, a deciduous shrub or small tree found in the southeastern USA. The common name is because its extremely light wood is less dense than that of cork. It was named in honor of the German natural scientist E.F. Leitner (1812-1838) who botanized in Florida until his early demise (at age 25) in a skirmish with Seminole warriors.

*Recent genetic research suggests it could belong in the Simaroubaceae family in the Order of Sapindales (soapberries); i.e. it would be botanically related to the maples.

Asimina triloba

Being related is relative according to my uncle. For example the genus Asimina is the sole member of Annonaceae, and that would suggest that there's really not much else like it. By contrast it shouldn't surprise you that two members – out of many – in the Rosaceae family, Malus and Crataegus, are quite similar. It doesn't take a botanist to know that because even a child can see the fruits, flowers and trunks look alike. Asimina triloba is native to eastern North America and the common name "paw paw" is probably derived from Spanish papaya. With a sweet custard-tasting fruit it was a favorite dessert of George Washington, and Thomas Jefferson planted it at Monticello, his home in Virginia. Before you gobble too many you should know that Asimina contains the neurotoxic chemical annonacin – hence the family name Annonaceae – which has been linked to palsy (PSP) and Parkinsonism.

Itea virginica 'Little Henry'

Itea virginica 'Little Henry'

The genus Itea is also a sole member in its family, Iteacea, and it is a genus of deciduous and evergreen shrubs mainly from eastern Asia. One exception is I. virginica from America, a small deciduous shrub which produces long banana-shaped racemes of fragrant flowers in summer. I see a section of the dwarf 'Little Henry' at the neighbor's bankrupt nursery, and I have to admit that I'd like one for my garden. His should have been shipped this past spring but they still remain, and I don't know – maybe his price is too high. In their root-bound state they are already starting to color deep red-purple. The origin of the name itea is from Greek for "willow," and I guess the flowers on the neighbor's plants do resemble those of a willow (Salix).

Helwingia chinensis 'Big Leaf Form (male)'

Helwingia male and female forms

Helwingia chinensis 'Variegated'

Another interesting family with a sole genus – Helwingia – is Helwingiaceae. We grow H. chinensis, and though the flowers are unimpressive, they do grow epiphyllously (if that is a word), in other words they sit atop the mid-vein of the leaves. More than anything it is a curiosity and I like to point it out to visitors. "Plants can be weird, eh?" I grow two cultivars of the evergreen, 'Big Leaf Form (male)' and 'Narrow Leaf Form (female)', though I'm not certain if these are official cultivar names. They originated from a Dan Hinkley 1996 expedition to Sichuan, China. I keep my bushes in a greenhouse in winter as they have not proven hardy outdoors. I have seen a variegated form in Japan but I'm not certain if the variegation is stable, or even if this selection is in America yet, but I would buy one if I could find it. The genus was named for Georg Helwing (1666-1748), a Lutheran pastor and botanist, but I doubt if he ever saw the plant.

Ilex crenata 'Dwarf Pagoda'

Ilex aquifolium 'Night Glow'

Ilex serrata 'Koshobai'

You might suspect that the Aquifoliaceae family's name was coined for water-like or glossy foliage...that Mahonia aquifolium refers to its wet-looking or shiny foliage. But wrong. The aqui in these cases refer to the barbs on the leaves...that somewhat resemble the beak of an eagle. I have laid this out in previous blogs, and though an interesting subject I won't go into it again. In any case, it is surprising to me that the Ilex genus is the only member of Aquifoliaceae. Ilex – the "Hollies" – is a huge genus of about 400 species of evergreen and deciduous trees and shrubs and we grow a number of them. Ilex crenata 'Dwarf Pagoda' is a wonderful evergreen (dark green) plant that won't outgrow its place in the garden. Ilex aquifolium 'Night Glow' never fails to amaze me for its luminosity, especially in winter. Ilex serrata 'Koshobai' (Japanese for "peppercorn") is a deciduous bush with the tiniest of red berries...borne in profusion, a perfect little potted treat for the Holiday dining table. Ilex – the Latin name first recorded in the 1500's – is the name for the "Holm oak," Quercus ilex, an evergreen from southern Europe that has foliage resembling that of the holly.

Corokia cotoneaster

The only member of the Argyrophyllaceae family is the Corokia genus. There are three species of Corokia, all from New Zealand, but I don't care for two of them. C. cotoneaster, however, is a fascinating shrub or small tree and we've been growing it for about 35 years. It is commonly called the "wire-netting bush" due to contorted branches and tiny silver leaves. Small yellow flowers appear in spring and orange fruits follow in autumn, but it is the curious branching that gives year-round appeal. The genus name is derived from Maori korokio while the family name refers to a group of plants with silver foliage.

Aristolochia durior

Aristolochia gigantea

 

Meerschaum Pipe

John Bartram

At some point the specific name of Aristolochia durior, in the Aristolochiaceae family, was changed to A. macrophylla. I'm not sure what prompted the change but now I have an added task to relabel my vine. It is a vigorous species that was introduced in 1763 from eastern North America by the early American botanist, horticulturist and explorer John Bartram.* The flowers are fun tubular things with a crook that give rise to the common name of "Dutchman's pipe." The family and genus name is derived from Greek aristos for "best" and locheia for "childbirth" or "childbed" due to its ancient use in childbirth.

Franklinia alatamaha 'Wintonbury'

*Linnaeus called him "the greatest natural botanist in the world." Bartram discovered and introduced a number of American plants including Kalmia, Magnolia, Rhododendrons and a wonderful flowering tree later named Franklinia alatamaha.

Cercidiphyllum japonicum 'Red Fox'

Cercidiphyllum japonicum 'Morioka Weeping' at Gossler Farms Nursery

I guess there is nothing else botanically similar to Cercidiphyllum, except that in appearance there are many trees with round leaves (Cercis, Disanthus etc.). But Cercidiphyllum, or "Katsura tree," is unique to the Cercidiphyllaceae family. We grow a number of forms such as 'Red Fox' ('Rot Fuchs'), an upright with red-purple foliage and 'Morioka Weeping', a large-growing tree with pendulous branches. The latter might have an invalid name due to the combination of a Japanese name with an English name. 'Morioka Weeping' originated at  the Ryugen Temple in Morioka city, and according to Hillier in the Hillier Manual of Trees and Shrubs, the original tree is respected as a natural monument, and that, "Incredibly, this tree itself originated as a sucker in 1824 from the stump of a previous large tree." I wonder about that, that maybe a new seedling germinated on or near the previous dead tree. Anyway it's a good story and I would love to visit the temple. The next best thing is to travel to Springfield, Oregon and see the large specimen at Gossler Farms Nursery.

Ginkgo biloba

Ginkgo biloba fossil

No one even remotely involved with plants would suppose the Ginkgoaceae family to contain anything other than Ginkgo, and besides the Ginkgo is a monotypic genus as well. According to Hillier, "G. biloba is the sole survivor of an ancient family whose ancestors occurred in many parts of the world (incl. the British Isles) about 190 million years ago." I have a wonderful fossil from the Paleocene* Period, found in Morton County, North Dakota. I am a huge fan of Ginkgo and have grown cultivars my entire career. When my daughter H. was two-years-old we were walking hand-in-hand down a Portland, Oregon street. She spotted a single golden leaf on the sidewalk and announced, "Ginkgo biloba," then looked up at the tree's canopy. When my older children heard the story they were worried that perhaps I was brainwashing the poor child.

*The name Paleocene comes from ancient Greek for palaios for "old" and kainos for "new," referring to the fauna that arose then.

Ginkgo biloba

Engelbert Kaempfer

Conifer authors include Ginkgo in their conifer books, and Rushforth in Conifers suggests that, "Ginkgo has survived until modern times in two remote areas in China, one on the border between Zhejiang and Anhui provinces in the east and the other further west in Guizhou." Earlier in my career my understanding was that Ginkgo was extinct in the wild, so I'm happy to learn of its wild survival. It was Linnaeus who bestowed the name upon the genus. It is known in Japan as ginkyo or "silver apricot," and it was the German physician and naturalist Engelbert Kaempfer (1651-1716) who visited Japan in 1691 and brought seeds back to Europe.

Sciadopitys verticillata

As with Ginkgo there is really nothing like a Sciadopitys, and you can't place it in the Pinaceae family even though it is commonly called the "Umbrella pine." Sciadopitys verticillata is a monotypic genus, the only member of the Sciadopityaceae family, and it is known as koyamaki in Japanese. The botanic name is derived from Greek sciado meaning "shadow"* and pitys meaning "pine," and of course the specific name verticillata refers to the needle whorls. Its native range is southeastern Japan at mid elevations with high rainfall and humidity, and so it is absolutely thrilled to grow in our greenhouses where it defies its reputation to be slow-growing. I invite you to look closely at a Sciadopitys because the needles that conduct photosynthesis are not technically the leaves; rather the true leaves are small scale-like growths that hug the branches. We grow a number of cultivars which I have featured over the years in the Flora Wonder Blog so I won't go into them now. Suffice to say that the straight species used to be in high demand twenty or thirty years ago, but not so much any more. My customers will pounce on any named cultivar, however, so you could say that the gardening elite has become more discerning.

*Another derivation is the Greek "skias" or "skiados" for "umbel." A few plantsmen pronounce Sciadopitys as "skee-a-dopitis" while most say "sigh-a-dopitis," and I include myself in the latter.

Euptelea pleiosperma

I grow a tree, Euptelea pleiosperma, but I have never once uttered its name. I bought 20 from a seedling grower who advertised that it was a root weevil magnet, that if you placed one in the middle of each greenhouse all of the weevils would reside near it, and then you would only have to spray one small area. I took the bait and put one in each greenhouse, but after a full season not a single leaf had been notched. It turns out that the Epilobium weed was much more of a magnet, for a couple of houses showed evidence that root weevils had munched on the weed. Anyway it took a few years before I was able to sell 18 of the trees, and then I planted the final two in the arboretum. Euptelea is no one's favorite tree and most would describe the genus as a BIO tree (Botanical Interest Only). In any case, it is the sole member of the Eupteleaceae family, and I guess you would pronounce its name as yoop tel ea. The generic name is derived from Greek eu for "well" or "handsome" and ptelea for the appearance of the fruits resembling the "elm." It comes from the eastern Himalaya and western China, and though it was introduced over 100 years ago, I challenge you to find even one in an American landscape or public park. BIO indeed.

Daphniphyllum himalaense ssp. macropodum

Daphniphyllum himalaense ssp. macropodum

Karl Ludwig von Blume

Daphniphyllum looks like an evergreen cross between Salix magnifica ("Wilson's willow") and Rhododendron decorum, but it's distinct enough to be the only member of the Daphniphyllaceae family. Despite its name,* it doesn't even look like any Daphne that I know. The specific name used to be macropodum, then we were told that it's himalaense subsp. macropodum – which is a lot to fit onto a label – but now Hillier is content with just macropodum. It is said to thrive in half shade (Hillier) but at Flora Farm I have a number of them growing happily in full sun, and remember we reached 106 degrees F this past summer. I grow three distinct variegated forms of Daphniphyllum, and all three originated in Japan. Nevertheless the nomenclature is murky and I wish an expert would help me to straighten it out...in other words, what are their names in Japanese? One came to me as simply 'Variegated', but that can't be right.

*The generic name was coined by Karl Ludwig von Blume (1796-1862), a German Dutch botanist.

Paulownia fargesii

Paulownia fortunei 'Fast Blue'

I've never grown a Paulownia, the sole member of Paulowniaceae, and all of the photos above were taken at other botanic gardens. It was first described by Siebold (originally as Pavlovnia) and honors Anna Paulowna, queen consort of The Netherlands, and is commonly called the "princess tree" for that reason. The genus comes from eastern Asia and it is a common roadside tree in China.* In Japan P. tomentosa is known as kiri and my wife plays a koto instrument made out of Paulownia.

*If happy, it can grow up to 20' in one year when young.

One of the best parts of the Hillier Manual of Trees and Shrubs (2014) is the glossary at the book's end. Also botanical names are described which Hillier calls "fascinating and rewarding." Another section is Genera Included by Family, and that's the part that inspired this blog, though I'm fully aware that contentious botanists in other publications do not always agree with Hillier.

To be sure some plant families contain genera that I have never heard of before, and it was a little bit of fun to look them up. For example Bupleurum in the Apiaceae family, Aextoxicom in the Aextoxicaceae family, Gelsemium in the Gelsemiaceae family and many others. Carpodetus is in the Rousseaceae family, and according to Hillier: "A small genus of 11 species of evergreen trees found in New Zealand and New Guinea." C. serratus is the "Marble leaf. A graceful, evergreen shrub or tree to 10 m with small, yellow  mottled dark green leaves and small, white flowers, in cymose panicles in summer." Of course I had to look up the meaning of cymose, and I discover that it's "Having flowers in cymes." A cyme is "An inflorescence where the terminal flower opens first, particularly referring to flat-topped inflorescences."

One can go on-and-on about plants, and my wife wonders why I come to bed late. I regret, however, that by tomorrow I will have forgotten all about Carpodetus and most of the others.