368 ORDER LXVIII. COMPOSITE. 



obovate, slightly serrate; cauline leaves sessile, scattered, oblong-lan- 

 ceolate, the lower ones similar to the radical. Flowers 3 — 5, terminal, 

 central one the largest ; involucre haves in a double series, linear-lan- 

 ceolate ; ray florets linear; disk florets yellowish. Seed compressed, 

 nearly glabrous; receptacle somewhat convex, dotted. — Pale blue. U- 

 March — April. Common. 1 — 2 feet. Robin's Plantain. 



3. E. stiugo'sum, (Muhl.) Stem pubescent, slightly scabrous. Radical 

 leaves linear-lanceolate, denticulate. ; cauline ones long, linear, entire. 

 Flowers in a terminal panicle; involucre with subulate leaves, pubes- 

 cent ; ray florets 2 — 3-cleft at the summit. Seeds hispid ; exterior pap- 

 pus minute scales, interior wanting, or a few pilose rays; disk florets 

 yellow. — White. %. May — Aug. Common in sandy pastures. 2 — 3 

 feet. 



4. E. ambig'uum, (Nutt.) Stem erect, pubescent, somewhat scabrous. 

 Leaves linear, lower ones serrulate. Flowers usually in pairs, axillary 

 and terminal ; involucre hemispherical. — Yellow. U- July — Aug. 

 Middle Geo. 1—2 feet. 



5. E. Philadel'phicum, (L.) Stem pubescent, slightly furrowed. 

 Radical leaves cuneate, obovate, sometimes incisely toothed ; cauline 

 leaves oblong-lanceolate, amplexicaul, entire. Flowers in loose co- 

 rymbs; ray florets capillary, numerous ; involucre many-leaved, with 

 the leaves arranged in two series, subulate. — White or pale purple. If. 

 Feb. — June. Common. 1 — 2 feet. 



6. E. quercifo'lhm, (Lam.) Stem pubescent. Radical leaves lyrate 

 and coarsely toothed ; cauline ones entire. Flowers few, terminal ;. ray 

 florets numerous ; involucre with numerous subulate leaves. — Pale 

 blue or white. % . July — Aug. Middle Car. 8 — 12 inches. 



7. E. Canaden'se, (L.) Stan hispid, paniculately branched. Leaves 

 linear-lanceolate, narrow, ciiiate. Flowers in racemose panicles ; invo- 

 lucre cylindrical, with acute linear leaves; ray florets numerous, short, 

 capillary; disk florets 4-cleft. Seeds somewhat hairy ; pappus simple, 

 pilose. — White. 0. June — Sept. Common. 1 — 8 feet. 



8. E. pusil'lum, (Nutt.) Stem glabrous, slender. Leaves linear-lan- 

 ceolate, entire, with scabrous margins. Flowers in simple panicles, 

 with divaricate brunches; involucre with narrow, acute leaves; ray 

 florets numerous, capillary ; pappus simple. — White. ^. July — Sept. 

 Common. 6 — 8 inches. 



The two preceding species, we think, ought certainly to constitute a distinct genus, 

 and we might add several varieties of these, differing from each other in a greater or 

 less degree. 



Gknls XVIII.— DIPLOPAP'PUS. Cass. (Aster of Ell.) 

 (From diploos, double, and pappus.) 



Heads many-flowered; rays 8 — 12; disk tubular, perfect; 

 scales of the involucre imbricate, subulate, lanceolate. Recepta- 

 cle flat. Pappus double ; interior of scabrous bristles, exterior 

 very short. 



1. 1). LiNAunKo'urs, (Hook.) [Chrysopsii linariifolia, Nutt.) Stem 

 erect, pubescent when young. Leave* numerous, linear, muoronate, 

 scabrous, rigid. Flower* in umbellate corymbs, with one at the ex- 

 tremity of each branch ; iuvolucre imbricate ; scales numerous, linear- 



