SiuM. UMBELLIFER^. 269 



DC prodr. 1. p. 125 ; Hook. fl. Bor.-Am. 1. p. 262 ; Torr. ^ Gr. fl. N. Am. 1. p. 611. 

 S. tenaifolium, Muhl. cat. p. 30. 



Roots thick, fasciculate. Stem 2-5 feet high, rather rigid, erect. Segments of the leaves 

 m 3 - 5 pairs, 2-4 inches long, mostly linear-lanceolate, but often linear and only 1 - 3 lines 

 wide. Rays of the umbel about 20. Leaflets of the involucre 5-10, sometimes 2-cleft. 

 Calyx-teeth very minute, acute, scarcely projecting beyond the margin of the stylopodium. 

 Petals broadly obcordate, the point small and inflexed. Fruit broadly oval or orbicular, 

 strongly ribbed ; the ribs whitish. Intervals with 1 - 3 vitta;. Commissure with 2-4 vitt^'. 



Swamps ; common. Fl. July - August. Fr. September. Our two species are still in 

 an unsettled state, for want of the, ripe fruit of the former. It is probable that they are not 

 distinct, as the differences in the involucrum and breadth of the leaves, and number of the 

 vitta;, are not constant. Whether they are distinct from the Sium latifolium of Europe, is 

 also uncertain. In my specimens of that species, the calyx-teeth are nearly as short as in 

 ours ; but I have never seen it with the leaves so narrow, and so sharply serrate as in our 

 S. linear e. 



8. CRYPTOT^NIA. DC.mem. Umb. p. 4:2; Endl. gen. AA09. bone-wort. 



[ From the Greek, kryptos, hidden, and tainia, a fillet ; the narrow vitta: being concealed in the carpels.] 

 Margin of the calyx obsolete. Petals obcordate, with a narrow inflexed point. Fruit oblong- 

 elliptical or ovoid, contracted at the sides, crowned with the short stylopodium and straight 

 styles. Carpels with 5 equal filiform obtuse ribs ; the lateral ones nearly marginal. VittE 

 very narrow, one beneath each rib and one in each interval. Seed somewhat teretely 

 convex ; the face slightly concave. Carpophore free, 2-cleft.— Perennial, smooth, erect 

 herbs. Root consisting of fasciculate fibres. Leaves 3-parted ; the segments ovate, entire 

 or 2 - 3-lobed, doubly serrate, with coarse mucronate teeth. Umbels numerous, somewhat 

 panicled. Rays of the umbel and umbellets very unequal. Involucre none. Involucels 

 none. Flowers white. 



1. Cryptot^nia Canadensis, DC. Common Hone-wort. 



Umbels opposite the leaves, and terminal; fruit oblong-elliptical. — DC. prodr. 4. p. 119 • 

 Hook. Jl. Bor.-Am. \.p. 262 ; Beck, hot. p. 144 ; Darlingt. fl. Cest. p. 189 ; Torr. 4- Gr. 

 fl. N. Am. 1. p. 613. Sison Canadense, Linn. sp. I. p. 252 ; Michx. fl. I. p. 168 ; JSi^e/. 

 fl. Boat. p. 114. Sium Canadense, Lam. diet. \. p. 407. Chaerophyllum Canadense, Pers. 

 syn. \.p. 320 ; Pursh,fl. 1. p. 195 ; Ell. sk. I. p. 358. Myrrhis Canadensis, Nutt. gen. 1. 

 p. 192 ; Sj^eng. in Schult. sysl. 0. p. 516 ; Torr. fl. 1. p. 310. Myrrhis Canadensis tri- 

 lobaU, Moris, hist. 9. t. 11. /. 4. 



Stem 1 i - 2 feet high, branched above, often purplish. Leaves very thin, and usually 



