TJMBELLIFER^E. (PARSLEY FAMILY.) 165 



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. AKCHEMORA, 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 temate, with the leaflets linear, entire and 

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

 folium, Torr. fr 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. Boot 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. Vittae 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. 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. CH^ROPHYLLTJM, 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 vittoe. 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 ; fruit oblong, 

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

 lina, and northward. April and May. (l)^>r 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. 



