UMBELLIFERiE. (PARSLET FAMILr.) 165 



1 T. teretifolia, DC. (Sium teretifolium, £//.) — Pine-barren swamps, 

 Florida to North Carolina, and westward. August. — Stem 2° - 4° high. Peti- 

 oles with cross partitions. 



20. ARCHEMORA, DC. 



Calyx 5-toothcd. Fruit oval or obovate, flattened on the back. Carpels with 

 5 slender obtuse ribs, winged on the margins. Intervals with single vittse, and 

 4-6 on the commissure. — Smooth herbs, with pinnately-divided leaves, and 

 white flowers. Involucre few-leaved or none. Iiivolucel many-leaved. 



1. A. rigida, DC. Leaves pinnate ; the leaflets (3-9) varying from lin- 

 ear to oblong, variously toothed or entire. (Sium rigidus, tricuspidatum, and 

 denticulatum, Etl.) — Swamps, Florida to Mississippi, and northward. August 

 and September. — Stem 2° -5° high. 



2. A. ternata, Nutt. Leaves ternate, with the leaflets linear, entire and 

 strongly nerved ; the lowest ones on very long petioles. (Neurophyllum lotlgi- 

 folium, Torr. §■ Gray.) — Low or swampy pine barrens, Florida to North Caro- 

 lina. November. — Stem slender, 2° high. Petioles of the lower leaves 1° or 

 more long. Root bearing tubers. 



21. HERACLEUM, L. 



Calyx-teeth minute. Fruit oval, flat. Carpels with the 2 lateral ribs distant 

 from the 3 dorsal ones, and near the dilated margins. Vittte shorter than the 

 carpels, single in the intervals, and usually 2 on the commissure. — Stout per- 

 ennial herbs, with pinnately or ternately divided or lobed leaves on inflated peti- 

 oles, and white flowers. Involucre few-leaved. Involucel many-leaved. Mar- 

 ginal flowers commonly larger and radiant. 



1 . BE. lanatum, Michx. Villous ; leaves very large, ternate ; leaflets 

 broadly cordate, deeply lobcd, hoary beneath. — Mountains of North Carolina. 

 June. — Stem 4° -8° high, strongly furrowed. 



22. CHJEROPHTLLUM, L. 



Calyx-teeth obsolete. Pruit oblong or linear, tapering at the apex, contracted 

 at-the sides. Carpels deeply furrowed on the commissure, with 5 obtuse equal 

 ribs. Intervals with single vittte. — Herbs, with compound finely dissected leaves, 

 and white flowers. Involucre few-leaved or none. Involucel many-leaved. 



1. C. procumbens, Lam. Stem weak, slightly pubescent; leaves ter- 

 nately divided ; the divisions bipinnatifid, with oblong obtuse lobes ; umbel 

 sessile, of 2 - 3 long rays ; involucel 4 - 5-leaved, few-flowered ; frait oblong, 

 abruptly pointed, finely ribbed. — Shady river-banks, Mississippi to North Caro- 

 lina, and northward. April and May. (l) or @ — Stem 6' - 18' long. 



2. C. Teinturieri, Hook. & Am. More pubescent ; lobes of the leaves 

 narrower and acute ; fruit oblong-linear, more strongly ribbed and tapering at 

 the apex ; otherwise like the last. — Banks of the Apalaehicola River, Florida, 

 and westward. March and April, — Stem erect, 1° high. 



