THE SESSILE-FLOWERED TRILLIA OF THE STATES.
In the spring of 1896, Professor Underwood and the writer in dependently became interested in a species of Trillium native in the southern Atlantic and the Gulf Professor Underwood collected his material in Alabama, while I received specimens col lected in western North Carolina, by my friend Mr. A. M. Huger.
The plant in question, judging both from descriptions and specimens preserved in our larger herbaria, has without exception been included in Trillium sessile. As I shall show, this is an error, and was committed by Linnaeus himself and both general bot anists, and monographers of this group have apparently followed his disposition of the plants to the present time.
Without doubt the original Tilllium sessile of Linnaeus was a composite species, for after his description, " Trillium flora ses sile erecto," he quotes descriptions from the three authors, Grono vius, Plukenet and Catesby, as follows: " Paris foliis ternatis, flore sessile erect°. Gron. virg. 44. Solanum virginianum triphyllum, flore tripetalo atropurpureo in foliorum sinu, absque pediculo, sessile. Pluk. alm. 352. t. i i I. f. 6. Solanum triphyllum, flore hexapetalo: tribus petalis purpureis, caeteris viridibus reflexis. Catesb. car. I. p. 5o. t. 50." The habitat given is " Virginia, Carolina." The first of these three descriptions throws little or no light on the subject, but the second and third quotations each refer to a plate. A comparison of these two plates indicates a great discrepancy, the figure of Plukenet representing a small plant with oval leaves, while the Catesby drawing illustrates a large robust plant with ovate-lanceolate leaves. If only these two plates had to be considered, there would be no doubt not only as to there being two distinct species involved, but we should have no trouble in deciding to which plant the name 7;illiurn sessile must be applied. The first quoted description being wholly indefinite, left this important question in doubt. In order to settle this point definitely, Dr. Britton sent specimens of both the small and large plants to Mr. Edmund G. Baker, at the British Museum, and I can not do better than print his reply : 1t We have the Gronovian plant and also a plant in the Plukenet Herbarium, written up by Plukenet, but not the one apparently the figure was done from, as you will see from the tracing I enclose. The Gronovian and Plukenet plants are fairly similar and more like no. 2 (the small plant with oval
leaves) than the much larger no. t (the large plant with ovate lanceolate leaves). Neither of the specimens are particularly good ones, but I have tried to make tracings of them, such as they are, these will show the outline of the leaf if they do nothing else. You may like to have exact measurements of the Plukenet plant : Leaves broadly oval, 2 in. long, breadth in., sepals in., petals _k in. I/ Thus we see that the first and second quoted descriptions in the Species Plantarum are represented by specimens which agree with each other in all essential particulars, while the third quota tion is founded wholly on a plate, which represents a species totally distinct from that on which the first and second descriptions were founded. Therefore the name Trillium sessile must be associated with the small oval-leaved plant, and the large plant must receive a name, which will appear in the appended synopsis. The solution of this ong-standing error naturally excited my interest in this whole group of and a study of the different species leads me to print the following key and specific descriptions which, I hope, will lead to a better understanding of these interesting plants.
As far as I can see, this group of Trillium has always been very unfairly treated ; most authors seem to have taken it for granted that the number of species was very limited and that that number could not be naturally increased. If an author did put his con victions in print, described a new species, pointed out excellent characters for a species and distributed specimens, that species was almost certain to find itself in synonymy or reduced to varicta, rank of another species at an early date. This state of affairs continued and reached a climax in Dr. Watson's treatment of the group in his revision of the North American Liliaceae,* where only two forms are given specific rank, while the rest arc included in the synonymy or varietal ranks under a much distorted nomen clature, for example, 7) Ilium vzride Beck appears as a synonym of Trillium sessile L., Trillium discolor Wray appears as a variety of Trillium Rustle under the new name Wrayi, Trillium viridescens Nutt. (T virM'e Beck) also appears as a variety of the Linnaean species under the new name Nultallii and Trillium lanccolatunz Boykin mss. is set down as a variety of recurvatum, which is fortunate enough to have retained specific standing.