388 Gleason : The pedunculate species of Trillium 



stigmas, the species are distinguished most certainly by the length 

 of the filaments and anthers, supplemented by the color of the 

 petals and ovary, and the length and position of the peduncle. 

 The absolute length of the stamens may be lessened considerably 

 by drying, but in that case the shrinkage is uniform, so that the 

 proportionate lengths of filaments and anthers remain unchanged. 

 The other specific characters, while quite typical of many species, 

 are either subject to considerable variation in nature or are easily 

 altered by pressing. The color of the ovary, for certain forms at 

 least, is quite constant. A very few species, such as 71 undulatum 

 and 7. nivale, may be distinguished by the shape of the leaves, 

 but in general the leaves and stems of all the species are very 

 similar. 



No attempt has been made to provide exhaustive descriptions 

 of the species. In some cases the characters used in the key 

 include all of the typical features ; in other cases a few additional 

 descriptive notes have been added in the text. 



Key to tlie species 



Stigmas sessile, short, stout, tapering from the base to the apex, 



recurved at the tip, their length about half that of the 6- 

 angled or 6-winged ovary. 

 North x\merican species; petals white, pink, or dark purple. 

 Ovary white or with a tinge of pink ; petals white or 



rarely pink ; peduncle nodding or horizontal. 

 Filaments one half as long as the anthers, or shorter. I . T. declinatitm. 



Filaments two thirds as long as the anthers, or 

 longer. 

 Ovary dark-purple or nearly black ; petals white to dark- 

 purple ; peduncle erect or declined, or rarely 

 nodding. 



Filaments 8-12 mm. long, approximately equaling 



the anthers. 

 Filaments 2-6 mm. long, shorter than the anthers 



or very rarely subequal to them. 

 Stamens 15 mm. long or more, much exceed - 



2. T. cernuum. 



3. T. Vaseyi. 



ing the stigmas. 4. 7'. simile. 



Stamens 13 mm. long or less, equaling or 



shorter than the stigmas. 

 Anthers purple, 8-10 mm. long, 2-3 



times as long as the filaments. 5. T. Rugelii. 



Anthers yellow, 5-9 mm. long, 1.2-2 



times as long as the filaments. 6. T. erectum. 



Species of eastern Asia and Japan ; petals white or none. 



