476 TRANS. OF THE ACAD. OF SCIENCE. 



and the form of the smaller seeds. These seeds are 0.25-0.33 

 line long, 2$ diameters being equal to the length ; appendages 

 about equal to the diameter, so that the whole seed has a 

 length of 0.40-0.60 line; 7-9 ribs visible, connected by deli- 

 cate cross-lines. 



Var. a is readily known by its low stature, rarely over a 

 foot high, erect, dark colored panicle (1-4 inches long and 

 i-lh inches wide) and elongated capsules, and therefore 

 longer fruit-heads; the sepals are usually acute, but in some 

 forms from Pennsylvania and from New Hampshire I have 

 found them obtuse. American botanists have usually taken 

 this form for J. acitminatus, Michx. ; but Michaux's plant 

 is very different and, moreover, comes from South Carolina, 

 while the present variety is, I believe, not found south of 

 Pennsylvania. Prof. Porter gets in the mountains of that 

 State a low foroi with more patulous lighter colored panicles, 

 and more obtuse sepals, Hb. n. 78, which seems to form a 

 transition to the next variety. 



Var. ft stands in habit and stature nearest to var. y, but 

 its small, short heads, obtuse sepals and short capsules dis- 

 tinguish it at once from that and from var. a ; our botanists 

 have sometimes confounded it with J. debilis or with J. arti- 

 culatus, from both of which however the characters enumer- 

 ated readily distinguish it. Stem H-2£ feet high; panicle 4-9 

 inches long and proportionately wide. Mr. C. E. Smith gets 

 a form at Tinnicum, near Philadelphia, which unites this 

 with var. y, having the seeds of this, but the greater number of 

 flowers (10-12), the larger heads, and the pointed sepals, of 

 the other. 



Var. y is a rather rare plant and does not seem to have at- 

 tracted the attention of botanists, though it had been collect- 

 ed especially about Philadelphia and in New Jersey, until 

 Mr. Bebb of Washington and Mr. Smith of Philadelphia stu- 

 died it with a great deal of attention; the shortness of the 

 appendages had induced some to place it away from its close 

 alliances and with or near J. acuminatus, but I cannot enter- 

 tain any doubt but that it is so closely allied to var. 6 that it 

 can barely be kept apart from it, the length of the append- 

 ages being quite variable even in seeds from the same capsule. 

 The whole plant, however, is more delicate, lighter green, the 

 stem weak, and more usually decumbent, the panicle very 

 loose, commonly with long and often horizontally-spreading 

 slender branches; heads pale, 8-15-20-flowered; flowers as 

 large as in the next, 1 J-2 lines long; sepals always subulate and 

 very acute, and often only 1 -nerved ; capsule more commonly 

 acute or acutate, as long or mostly longer than the sepals ; 

 seeds 0.25-0.36 line long, thicker than in the next variety, the 

 length being equal to 2-2* diameters ; seed with appendages 

 0.33-0.50 or very rarely 0-60 line long ; appendages less than 



