458 TRANS. OF THE ACAD. OF SCIENCE. 



single, two-flowered heads; fruit and seed are unknown. I 

 take it for a depauperate water form of our species, while 

 Hooker, Fl. Bor. Am. 2, 191, unites it with J. uh'yinosus, 

 which with him is what I have taken for J. alpima ; but 

 that is also a 6-androus species. The botanists of Canada 

 and of our northern border ought to find it again and clear 

 up these doubts. 



I have already (p. 426) spoken of the great morphological 

 importance of this plant, which connects the single-flowered 

 with the head-flowered species, and proves, as certainly might 

 have been expected beforehand, that no absolute difference 

 exists between them ; that the flowers in all of them are 

 really lateral ; that in the former only one flower is formed, 

 while in the others a series of them, from two to an indefinite 

 number, are developed in centripetal order. In our species a 

 second flower is more commonly not present, and its place is 

 occupied by a bud, which often, and especially later in the 

 season, grows to a leafy excrescence (whence the name vivi- 

 fyarus); sometimes even the first flower is replaced by a leaf- 

 bud, and in rare instances a leaf-bud makes its appearance 

 between two flowers as a third axillary organ. I have 

 never seen more than two flowers, nor more than one leaf- 

 bud in a head. Botanists who have the opportunity ought 

 to investigate the variations in the inflorescence of this plant 

 according to locality, season, or other circumstances. 



33. J. articulatus, Linn.; that form of the Linnean spe- 

 cies which was distinguished by Ehrhart as J. lampocarjyus, 

 and which is common in northern Europe, has a very limited 

 range in North America. All the specimens I have seen 

 came from the New England States (Boston, Pickering; 

 Amherst, Tuch&rman; and Providence and Nantucket, 01- 

 ney) and from western New York (Penn Yan, Sarticell); to 

 these La Harpe adds Newfoundland. — Stems densely cespi- 

 tose from a creeping root-stalk, with us usually erect and 

 about one foot high ; panicle short, dense-flowered, spreading, 

 brown ; sepals mostly equal, lanceolate acute and mucronate, 

 or inner ones slightly longer and sometimes obtusish ; stamens 

 about two-thirds the length of the sepals, and anthers as long 

 as filaments; ovary acuminate, terminating in a style about 

 half its length; capsule longer than the sepals, acute, or even 

 rostrate, at least in all the American specimens seen by me, 

 and imperfectly three-celled, the placental not meeting in the 

 centre. Seeds obovate, obtuse at the upper, acute at the 

 lower, end, and at both strongly apiculate ; 0.3 line or a little 

 less long, and about half as much in diameter; reticulate, 

 with areae finely cross-lineolate ; 7 or 8 ribs visible. 



34. J. acinus, Villars, Delph. 2, 233 ex Koch Syn. Germ. 

 730; J. fusco-ater, Schreb. ex Kunth En. 3, 326, J. ajfinis, 



