l^l*^] Goodspeed^Brandt: Notes on Trillium 5 



affected by variation in illumination that height, general habit and, 

 as can be seen, the presence or absence of a slight petiole, are not 

 to be taken as reliable criteria for species differentiated. 



T. ovatum is thoroughly described by Jepson,- and only a few 

 points are worthy of special mention. In color of flower this species 

 is characteristically a chalky white and the lack of variation in color 

 is striking in connection with the extreme variability of T. sessile 

 var. giganteum in this character. After anthesis and while fading 

 the petals become distinctly pigmented to such an extent in many 

 cases that the petals may become deep rose-red as they Avither. 

 Herbarium specimens of this and other white-flowered species seem 

 to show a considerable variation as to the presence or absence of this 

 pigmented condition. According to our preliminary observations on 

 this matter, it appears that a plant collected before pollination or 

 fertilization may not exhibit the pigmented condition when dried, 

 but that when collected after pollination or fertilization the color will 

 appear on drying even though not apparent when collected. 



Turning now to T. sessile var. giganteum, there seems to be no 

 doubt that this Californian plant represents at least a very distinct 

 modification of the eastern T. sessile. The difference in size between 

 the eastern and western forms is very striking and it may ultimately 

 seem desirable to accept the western form as a distinct species under 

 the name T. giganteum (H. & A.) Heller. T. sessile var. giganteum 

 is, again, fully described by Jepson,^ but a number of points, 

 especially with reference to its variability in certain characters, are 

 worthy of note. Characteristic individuals of the Californian variety 

 of T. sessile just coming into full flower are shown in plate 1, figure 

 1, and in plate 3, figure 6, a vigorous and characteristic plant fully 

 in flower. The very considerable size of all characters may be seen 

 by reference to plates 1 to 3. As noted below, we have undertaken 

 a rather extensive statistical study of the size relations of vegetative 

 and floral characters and it is hoped that measurements of the 

 eastern T. sessile can also be obtained. Since our data are not 

 entirely complete and we do not know the exact limits of variation 

 of corresponding characters peculiar to eastern species, it seems best 

 to discuss only in very general fashion the variation in size of the 

 leaves and flower parts of T. sessile var. giganteum. 



At the start it might be noted that for all characters the limits 



2 Op. cit., p. 108. 



3 Op. cit., p. 109; cf. Garden and Forest, vol. 3, p. 320, 1800. 



