398 ORDER Lxvni. COMPOSITE. 



Genus LXIL— HELE'NIUM. L. 



(Named from Helen, the celebrated Grecian.) 



Involucre gamosepalous, many-parted ; florets of the ray pis- 

 tillate, of the disk perfect. Pappus chaffy, 5-awned. Recepta- 

 cle globose, naked. 



1. II. altlmna'le, (L.) Stem erect, branching toward the summit, 

 glabrous, winged by the decurrent leaves. Leaves sessile, alternate, 

 lanceolate, doubly serrate, glabrous. Flowers in small con-mbs ; invo- 

 lucre 8-parted, with subulate segments, longer than the disk ; ray flo- 

 rets about 10, 3-toothed at the summit. Seed angular, larger at the 

 summit; scales of the pappus lacerate, mucronate. — Yellow. %. Oct. 

 — Nov. In wet soils. 2 — 3 feet. 



2. H. paviflo'rum, (Nutt.) Stem branched, glabrous, slightly angu- 

 lar. Leaves lanceolate, sub-serrulate ; scales of the involucre filiform ; 

 rays 5-toothed ; pappus awned. Heads solitary or in pairs. — Geo. 



3. H. tenuifo'lium, (Nutt.) Stem much branched. Leaves crowded, 

 narrow, linear, entire. — Mis-. 



4. H. quadridenta'tum, (Lab.) Stem erect, pubescent, slightly wing- 

 ed by the decurrent leaves. Leaves narrow-lanceolate, entire, pubes- 

 cent. Floicers solitary and terminal ; ray florets obovate, 3 — i-toothed. 

 Seeds hispid ; pappus consisting of 6 mucronate scales; receptacle ob- 

 long. — Yellow. If. Sept. — Oct, Swampy lands. 2 — 3 feet. 



Genus LXIIL— LEPTOPO'DA. Nutt. 

 (From leptos, slender, and pous, foot or support, from its slender stem.) 



Involucre many-leaved, in double series ; ray florets neutral, 

 dilated at the summit, 3-cleft ; those of the disk perfect. Re- 

 ceptacle convex, naked. Seed cylindrical. Pappus membrana- 

 ceous, 8 — 12-leaved. 



1. L. Hele'xium, (Nutt.) (L. decurrens, Mac.) Stem glabrous, sim- 

 ple, striate, solid. Leaves decurrent, somewhat denticulate. Flowers 

 solitary, terminal ; involucre with the interior leaves subulate, pubes- 

 cent at the summit ; ray florets somewhat pubescent. Seed glabrous ; 

 pappus awned, fimbriate. — Yellow. If. March — April. Middle Geo. 

 1—2 feet. 



2. L. inci'sa, (T. <fe G.) Stem glabrous. Leaves lanceolate, obtuse, 

 sessile, not decurrent, pinnatifid or incised ; rays in 2 or 3 series. Ache- 

 ttia glabrous, striate. — Geo. 



3. L. fimbria'ta, (T. & G.) Stem glabrous. Leaves lanceolate-acute, 

 usually decurrent; radical ones oblauceolate ; scales of the pappus 

 deeply fimbriate. — Florida. 1 — 2 feet. 



4. L. PDBBk'ula, (Mac.) Stem simple, viscidly pubescent, striate, fist- 

 ular. Radical leaves obovate or Linear-lanceolate, slightly serrate ; 

 eauline leaves alternate, linear-lanceolate, glabrous, notched, and tooth- 

 ed. Flowers terminal, solitary ; involucre with the outer leaves subu- 

 late, pubescent, longer than the interior; rav florets numerous. Seeds 

 hairy; pappus fimbriate, — Yellow, if. April — May. In damp soils. 

 Car. and Geo. 2 — 3 feet. 



