171 



of this ong-standing error naturally excited my interest in this 

 whole group of Tnlluiin, 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 Trillmm 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 varieta, 

 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 are included 

 in the synonymy or varietal ranks under a much distorted nomen- 

 clature, for example, TnlluLm viride Beck appears as a synonym 

 of Trilluwi sessile L., Trilliuin discolor Wray appears as a variety of 

 Trilliiun sessile under the new name Wrayi, Trillium viridescens 

 Nutt. \T. viride Beck) also appears as a variety of the Linnaean 

 species under the new name Niittallii and TrUliuvi lanccolatmn 

 Boykin mss. is set down as a variety of Trillium reciirvatum, which 

 is fortunate enough to have retained specific standing. 



Key to ttie Species. 



Petals'sessile, of one color throughout. 



Sepals oblong or oblong lanceolate ; petals broadly spatulate. 



I. T. discolor. 

 Sepals lanceolate ; petals lanceolate, elliptic or oblanceolate. 



Leaves oval or suborbicular, 4-8 cm. long ; anthers 3-4 times longer than the 



filaments ; styles elongated, nearly straight. 2. T. sessile. 



Leaves ovate-lanceolate to ovate-orbicular, 8-18 cm. long; anthers subses- 

 sile ; styles almost wanting, stigmas recurved. 3. T. Underwoodii. 



Petals clawed, the blade and claw often of different colors. 



Leaves sessile ; blades of the petals linear or linear-oblong. 



Stems rough pubescent at least above; leaves ovate or oblong; sepals 2.5-5 



cm. long ; filaments— ^-J shorter than the anthers. 4. T. viride. 

 Stems smooth; leaves lanceolate or elliptic; sepals 2-2.5 cm. long; fila 

 ments about as long as the anthers. 5. T. lanceolatum. 



Leaves petioled ; blades of the \ etals ovate, elliptic or obovate. 



6. T. recurvatum. 



*Proc. Am. Acad. 14: 213-303. 



