162 UMBELLIFERJE. (PARSLEY FAMILY.) 



9. DISCOPLEUBA, DC. 



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

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

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

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

 lucel conspicuous. Flowers white. 



1. D. capillacea, DC. Umbels 3-10-rayed; leaves of the involucre 

 mostly 3-5-clcft ; fruit ovate. (Ammi capillaceum, Michx.) Brackish marsh- 

 es, Florida to Mississippi, and northward. June and July. Stem 1 -2 high, 

 much branched. 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 Ogeechee Kiver, 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, Koch. 



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

 carpels equally 5-ribbed. Intervals with single vittse. Flowers white. 



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

 leaflets ovate-lanceolate, sen-ate ; umbqls short-peduncled, opposite the leaves ; 

 involucre 1 - 2-leaved or none; involucel 5-6-leaved. (Sium nodiflorum, L.) 

 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 vittse. 

 Marsh or aquatic perennial herbs. 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 

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

 streams, commonly in water, Florida to Mississippi, and northward. July. 

 Stem 2 high. 



12. BUPLEURUM, Tourn. 



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

 Carpels 5-ribbed, the intervals with or without vittse. Smooth herbs, with en- 

 tire simple leaves, and yellow flowers. 



1. B. rotundifolium, L. Leaves ovate, perfoliate ; umbel 5-rayed ; in- 

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

 lina. Introduced. 



