umbellifer^e. (parsley family.) 105 



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



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

 oles with cross partitions. 



20. ARCHEMORA, DC. 



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

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

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

 white flowers. Involucre few-leaved or none. Involucel 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, Ell.) — 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. (Xeurophyllum longi- 

 folium, Torr. Sf 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. Vittoe shorter than the 

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

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

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

 ginal flowers commonly larger and radiant. 



I. H. lanatum, Michx. Villous; leaves very large, ternate; leaflets 

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

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



22. CHJEROPHYLLUM, L. 



Calyx-teeth obsolete. Fruit 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 vittre. — Herbs, with compound finely dissected leaves, 

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



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

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

 scs-ile, of 2-3 long rays; involucel 4 - 5-leaved, few-flowered; fruit oblong, 

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

 lina, and northward. April and May. (£ 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 Apalachicola River, Florida, 

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



