162 PMBELLIFER^. (PARSLET FAMILY.) 



9. DISCOPLEURA, DC. 



Calyx-teeth subulate, persistent. Fruit ovate ; the carpels strongly 3-ribbed 

 on the back, and witli two lateral ribs united with a thick corky margin. Inter- 

 vals with single vittai. — Smooth annuals, growing in marshes. Leaves pin- 

 natcly dissected, with the filiform divisions often whorled. Involucre and invo- 

 luccl conspicuous. Flowers white. 



1. D. capillacea, DC. Umbels .3-lO-rayed; leaves of the involucre 

 mostly 3-5-ckf:; fruit ovate. (Arnmi capillaccum, ^ficll.r.) — Brackisli marsh- 

 es, Florida to Mississippi, and northward. June and July. — Stem l°-2° high, 

 much branciicd. Earliest leaves simple, or simply pinnate. 



2. D. COStata. Stem tall, branching above ; leaves of the involucre 10 - 

 12, many-parted ; fruit ovate, deeply sulcate. ( Ammi costatum, Ell.) — Swamps 

 of the Ogcechec River, Georgia. October and November. — Stem 4° - .5° high. 

 Fruit larger than in No. 1. 



3. D. Nuttallii, DC. Umbels many-rayed ; leaves of the involucre 5-6, 

 entire ; fruit globose. — Tampa Bay, Florida, and westward. — Stem 2° - 6° 

 high. 



10. HELOSCIADIUM, Koeh. 



Calyx-teeth .'5, or obsolete. Fruit ovate or oblong, flattened on the sides, the 

 carpels equally 5-ribbed. Intervals with single vitta;. Flowers white. 



1 . H. nodiflorum, Koch. Stems prostrate or creeping ; leaves pinnate ; 

 leaflets ovate-lanceolate, serrate ; umbels short-pcdunclcd, opposite the leaves ; 

 involucre 1 - 2-leaved or none; involucel 5-6-lcaved. (Slum nodiflorum, Z/.) 

 — Ditches, &c. around Charleston. Introduced. April - June. — Stems 2® 

 long. 



11. SIUM, L. 



Calyx -teeth small or obsolete. Fruit ovate or globular, flattened at the sides ; 

 the carpels with 5 equal corky ribs. Intervals usually with several vitta;. — 

 Marsh or aquatic perennial hcrl)s. Leaves pinnate; the immersed ones dissected 

 into numerous capillary divisions. Involucre several-leaved. Flowers white. 



1. S. lineare, Michx. Leaflets varying from linear to oblong, finely and 

 sharjily serrate ; calyx-teeth minute ; fruit globular, strongly ribbed. — Along 

 streams, commonly iu water, Florida to Mississippi, and northward. July. — 

 Stem 2° high. 



12. BUPLEURUM, Toum. 



Calyx-tccth obsolete. Fruit flattened at the sides, or twin, ovate-oblong. 

 Carpels 5-ribl)ed, the inten'als with or without vitta;. — Smooth herbs, with en- 

 tire simple leaves, and yellow flowers. 



1. B. rotundifolium, L. Loaves ovate, poifoliatc ; umbel .'i-rayed ; in- 

 volucre none ; leaves of the involucel 5, ovate, mucronato. — Fields, North Caro- 

 lina. — Introduced. 



