Wildflowers from East and West by RICHARD E. WEAVER, JR. Soon after plant explorers started bringing their specimens out of Japan, it became obvious to plant geographers and other botanists that the flora of that country was similar in many ways to the flora of eastern North America, and to a lesser extent, that of western North America as well. Asa Gray, Professor of Natural History at Harvard, was one of the first to draw the attention of the scientific community to this phenomenon, and he enumerated a list of about ninety genera of plants that occurred in two of these three areas and nowhere else on earth. As the rich flora of China became known, a similar relationship became obvious. The reasons for the similarity of the flora of such widely separated geographic areas appears to have begun during the Tertiary era of geologic time (starting more or less seventy million years ago), when the climate of the earth was much different from today, and a rich forest of quite uniform composition covered much of the Northern Hemisphere. As climate changed and glaciation occurred, and as the continents became separated, much of this forest disappeared. Relicts remained primarily in eastern North America, Pacific North America, and eastern Asia, where the climate remained relatively stable. But the relict floras were then widely separated, and the plants of each geographic area evolved separately, resulting in similar but not identical floras. As a result, although certain genera may be common to two of the three areas, the representative species are often slightly different. In some cases, evolution proceeded a bit further, and the related plants are now classified in different genera. In other cases, a group became extinct in all but one of the areas. Several years ago, I began to gather a collection of plants repre- sentative of this ancient Arcto-Tertiary forest, as it is commonly known. Following is an account of my experiences in growing some of these as well as descriptions of others I hope to grow someday. I have included plants from only a few selected families; all are her- baceous rather than woody. I shall call them wildflowers, a term that I find useful, although many other people consider it nebulous, misleading or unscientific. First of all I offer a word of warning, or perhaps a tantalization. Many of the Asiatic plants are rare in cultivation in this country so they are difficult to obtain unless one is willing to import them from 169 170 abroad. A plant import permit may be obtained by writing for an application at the following address: Permit Unit USDA APHIS, PPQ Room 638 Federal Building Hyattsville, Md. 20782 At the end of this article I have included a list of nurseries, together with a few of their specialties, where I have been able to find some of these very fine plants. Second, I offer a short general description of the growing condi- tions under which I have been working. Many people might con- sider wildflowers difficult to grow in anything other than a "woodsy" situation. My gardens have been in the City of Boston, in anything but such a setting. The first was in a small backyard, under the high shade of a White Ash and in the additional shade of the house for the entire afternoon. The whole yard had previously been a sand- lot, so large amounts of organic matter were dug in. Most plants, particularly orchids, did well, although frequent watering was neces- sary, particularly in the early spring before the ash leafed out. I recently moved my garden to a new location, most of it under the low shade of an old apple tree. The soil had previously supported a lawn, and it was quite heavy. I dug in a half-ton of sand and a good bit of organic matter. Again, the garden appears to be very success- ful, and it does not require a great deal of supplementary watering. A smaller part of my new garden is at the edge of a clump of hem- locks. The soil is light, humusy, and a bit dry. My only problem there has been the unidirectional sunlight, which causes the taller plants to "stretch." The Arum Family (Araceae) is a large group of plants that has reached its greatest diversity in tropical regions. Many members of the family, for example Philodendron, Dieffenbachia and Anthurium, are among the most commonly grown foliage plants in our homes; others are familiar wildflowers in temperate regions. Arisaema Plants of the Arum Family are easy to recognize because of their distinctive type of inflorescence. The individual flowers are small and inconspicuous, but they are arranged on a fleshy spike technic- ally termed a spadix. This structure is surrounded or even covered by a modified and commonly colorful leaf known as a spathe. The familiar Jack-in-the-pulpit (Arisaema) will serve as an illustrative example. The "jack" is the spadix and the "pulpit" is the spathe. This genus of about one hundred fifty species is most diversified in temperate and subtropical Asia, but a few species are native to eastern North America. Most authorities have considered our common Jack- 171 in-the-pulpit to be a single species, Arisaema triphyllum, variable in the shape, size, and color of the spathe. Now many botanists divide these plants into several species, restricting A. triphyllum to include only those plants with the spathe usually dark inside and not fur- rowed (without longitudinal ridges) on the outside, and with the hood horizontal rather than arched. At any rate, these are curiously attractive plants with their distinc- tive inflorescences followed by clusters of brilliant scarlet berries and their bold, three-parted leaves. The large, fleshy tuber from which they grow has given rise to an alternative common name, Indian Tur- nip. Although the tuber is edible, it and all other parts of the plant contain crystals of calcium oxalate which, unless they are destroyed by repeated boilings, are excruciatingly irritating to the delicate linings of our digestive tract. Closely related but quite different in appearance and much less common, the Green Dragon, Arisaema dracontium, is native to rich woods through much of the eastern United States and adjacent Canada The leaves are rather curiously constructed, with five to fifteen leaflets of greatly varying size. The inflorescence is even more curious with its elongated spadix, the shorter flower-bearing portion tightly enclosed by the slender spathe. Most of the forty or so Japanese species are generally similar to Arisaema triphyllum, although the spathes are variously colored, and the leaves often have more than three leaflets. Others, however, are bizarrely different. Arisaema thunbergii and its closest relatives are almost lurid in appearance. The spathe of A. urashima, one of these species I have grown, is large and dark reddish-purple streaked white, with a white blotch on the inside of the hood. The spadix is dark red- purple and greatly elongate, projecting as much as a foot from the spathe. The solitary leaf has a stout, purple-blotched stalk; the blade itself is divided into two parts, the axis of each strongly curved with the leaflets arranged only on the outer edge. Arisaema sikokianum, on the other hand, is delicately beautiful. It is a small plant, less than a foot tall, and the inflorescence is well developed before the leaves expand. The spathe has a narrow, dark purple tube and an erect hood that is purple streaked with white. The spadix is pure white and the tip is expanded into a ball-shaped structure. The leaves have three to five leaflets, each one with a central, paler blotch. None of the Asiatic species is generally available in this country. Many of the Japanese species should be hardy even here in New England with some protection in the winter, although I say this from their distribution in the wild rather than from experience since even the two species that I have been able to procure have yet to pass the test of a single winter outdoors. The Himalayan species, including some of the most wonderful of all, are probably tender. 172 Arisaema triphyllum is of the easiest culture and it may even be- come weedy. It is not fussy about soil, and it will flower well in moderate shade to nearly full sun. Arisaema dracontium prefers moister conditions with more shade, and so, I suspect, do the Asiatic species. - Symplocarpus and Lysichiton The plants commonly called Skunk Cabbage are included in two different genera: Symplocarpus, with two or three species in eastern North America and eastern Asia, and Lysichiton, with two species in western North America and eastern Asia. They are similar plants with their thick spadices, colored spathes, and very large basal leaves appearing with or after the inflorescences. All are plants of moist to mucky soil, and they require the same for successful cultivation. Symplocarpus foetidus is the common Skunk Cabbage of the eastern United States. Its fleshy, reddish-purple spathes variously streaked and flecked with yellow-green usually poke out of the still frozen soil before the end of February in the Northeast. Their odor when crushed, and the large leaves that follow them by about a month, are the source of the plants’ common name. The Japanese S. renifolius is so similar that it is often classified as a variety of our plant. The other Japanese species, S. nipponicus, differs in the shape of the leaves and in the fact that the leaves appear with the inflorescences. Neither of the Japanese plants is in cultivation to my knowledge.