262 UMBELLIFER^. [Slum. 



1. C, Canadensis; umbellis infimis ex foliorum superiorum axillis ortis, fructibus 

 oblongis. De Cand, Prodr, v, 4. p, 118. — Sison Canadense. Linn, Sp, PL p, 363. Mich. 

 Am. V. 1. p. 168. Bigel, Fl. Bost. ed. 2. p. 114. Slum Canad. Lam. — Chseropliyllum 

 Canad. Pers. — Myrrhis Canad. Moris. — Torrey^ Fl. of Un. St. v. 1. p. 310. — Conopo- 

 dium Canad. Koch. 



H.\B. Canada. Lake Huron and Quebec. Dr. Todd. Mrs. Percival. — It is chiefly confined to the 

 more southern parts of Canada in British North America.* 



10. SIUM. Koch. 



Ccdycis margo 5-dentatus subinde obsoletus. Petala obovata emarginata cum lacinula 

 inflexa, Stylopodium pulvinatum margine depressum. Styli divergenti-reflexi apice 

 capitulati. Fructus a latere compressus vel contractus et subdidymus, stylopodio stylisque 

 coronatus; mericarpia jugis sequalibus filiformibus obtusiusculis, valleculis et commissura 

 multivittatis. Carpophorum bipartitum, cruribus niericarpio adnatis, stylopodio pulvinato 

 margine depresso. Semen subteres. — Herbae plerumque aquaticce. Folia pinnati-secta 

 segmentis ovatis oblongis dentatis aut midtipartitis. Umbell£E terminales multipartitcB ; 

 involucre polyphyllo, rarius submonophyllo. Umbellulee multiJlorcB, involucello polyphyllo. 

 Flores albi. DC. 



1. S. latifolium; radice repente, caule sulcato-angulato, foliis pinnatisectis segmentis 

 lanceolatis acuminatis basi ineequalibus serratis rarius pinnatifidis, involucre polyphyllo, 

 dentibus calycis elongatis. DC. — Linn. Sp. PL /?. 361. Engl. Bot t 204. Bigel. Fl. Bost. 

 ed. 2. p. 111. Torrey, Fl. of Un. St. v. 1. ^. 311. De Cand. Prodr. v. 4. p. 124.^ — (3. foliolis 

 profunde inciso-serratis. 



Hab. Watery places, Saskatchawan. Drummond. /3, Straits of De Fuca, North -West coast of America. 



Dr. Scouler, — I find it scarcely possible to distinguish some narrow-leaved states, of what I consider to be 



this plant, from the following ; and I am here again much disposed to concur with Dr. Torrey in thinking 



they may he only varieties of each other. The present seems to me identical with the Europaean S, lati- 

 folium. 



2, S, lineare; caule angulato sulcato, foliis pinnatisectis segmentis 4-5-jugis lineari- 

 lanceolatis acute et tenuiter hinc inde serratis, involucro oligophyllo lineari. DC. — Mich. 

 Am. v.l. p. 167. Pursh, Fl. Am. v. I. p. 194. Torrey, Fl. of Un. St. v. I. p. S12. De 

 Cand. Prodr. v. 4. p. 125. 



Hab. Watery places. Lake Huron. Dr. Todd. Canada, to the mountains and the Saskatchawan. 

 Drummond, Moist and overflowed grounds of the Columbia. Dr. Scouler. Douglas. — The young sub- 

 merged leaves of this plant are deeply multifid or tripinnate, with very narrow linear-subulate segments. 



• This appears, like many other Canadian plants, to be not unfrequent about BcstoD, U. S. The nature of this 



work only admits of my mentioning, under the respective species of plants, the names of those persons who have 

 favoured me with them from the British Possessions. But I am unwilling to wait till the introductory pages of this 

 work go to press, without expressing my acknowledgments to my valued friends, Dr. Boott of London, and B. D. 

 Greene, Esii. of Boston, U. S. A., for the valuable assistance rendered me in the numerous and beautifully preserved 

 plants they have sent me from the New England States, which, as may be expected from the vicinity of the two 

 countries, are intimately connected with those of Upper Canada : whilst those from the "White Mountains, sent me 

 by the same gentlemen, are almost identical with many from the Rocky Mountains, and from the Arctic regions. 



