46 



Seliiiiiiii. with whicli gcmis it in verv (.-losoly allied. The chief differences 

 are the more decidedly dorsally flattened fruit, lets prominent (not winged) 

 dorsal and intermediate i-ibs, laterals broadly winged, and thick conical 

 stylopodium, numerous small oil tubes, and concave seed-face of Coniose- 

 lintim. Our species is related to Scliuidti through S. Hookrri, which 

 it vei-y closely resembles. 



1. C. Canadense Torr. & Gray, Fl. i. Oil). One to five 

 feet high, ghxhrous except the somewhat puberulent inflorescence: 

 leaves often very large, with inflated petioles, 2 to 8-pinnate (or 

 the primar}' divisions apparently tevnate in the larger leaves), the 

 ovate acute segments an inch or more long, laciniatel}' lobed : um- 

 bel 10 to 20-rayed; rays about an inch long; pedicels 3 to 4 lines 

 long: fruit 2 to 2^4 lines long, (Fig. 23.) — Selinum Canadense 

 Michx. Fl. i. 1()5. 



Swamps and cold cliffs, from the mouth of the St. Lawrence (Michuux) 

 to Vermont and Minnesota, and extending southward into Illinois, Indiana, 

 and Missouri; also along the highest mountains as far south as North 

 Carolina. FL August to October. The stations reported from the United 

 States are as follows: Y eimont (Tnlly. Pringle), Massachusetts (0«A-e.s), 

 New York (KneAskern, Hoysradt, Dudley), Pennsylvania (Porter), North 

 Carolina {Gray d- Carey), Indiana (Rose), Illinois (Vasey), Missouri 

 (Tracy, Broadhead), Iowa (Arthttr), Minnesota (Garrison), Wisconsin 

 (Lap ham), and Michigan (Wheeler d- Smith); also in the mountains of 

 Colorado, where it is confused with Ligusticum ncopvlorum. Apium 

 bipinp.atum Walter has also been very doubtfully referred to this species, 

 but Walter's plant is altogether uncertain, and his locality is a presumptive 

 evidence against such reference. 



10. TIEDEMANNIA DC. Mem. Umbel 51.— Smooth 

 erect swamp herbs, with 'fascicled tubers, leaves simply pinnate or 

 ternate or reduced to petioles, involucre of few bracts or none, in- 

 volucels of numerous small bractlets or none, and white flowers. 

 — Incl. Archcmora DC. 



Bentham »t Hooker have included both Tiedemannia ar\(S. Archemora 

 under Peueedonum. Their habit and habitat are totally different from our 

 species of Pencedannm, which are low dry ground western forms, with 

 much dissected leaves, and roots never fasciculate-tuberous. The fruit 

 characters are no less distirtguishable, that of T iedemanri ia heingles^ 

 flattened than in Peucedanum, with a thick conical stylopodium, and 

 alwaj's appearing to have 5 filiform dorsal ribs (owing to the prominent 

 inner marginal nerves of the lateral wings). In Peucedanum when the 

 lateral wings are nerved it is always on the commissural sido as in Lepio- 

 tcenia. These characters, which servo so well to separate Tiedemuunia 



