COMPOSITE. 191 



equal ; the outer series often large and leafy. Receptacle flat- 

 tish, chaffy. Achenia obcompressed, not winged, crowned with 

 2 — 5 retrorsely pilose rigid awns. 



1. B. cernuaLinn.: smooth; leaves undivided, lanceolate, toothed, the 

 upper somev^hat connate ; heads discoid or radiate, on slender peduncles, 

 usually nodding ; outer involucre longer than the head ; achenia 4-awned, 

 retrorsely ciliate on the margin. 



Near ponds and ditches. Can. to Penn. W. to Oregon. Aug., Sept. (T)- — 

 Stem 1 — 2 feet high. Heads usually discoid, but sometimes more or less radiate ; 

 rays, when present, yellow. This plant is sometimes not more than 6 or 8 inches 

 high, with very small erect flowers, when it constitutes the variety minima. 



Swamp Beggar-ticks. 



2. H. chrysanthevwides Mich. : stem smooth ; leaves undivided, oblong- 

 lanceolate, tapering at each end, connate at base, dentate-serrate ; heads 

 radiate, somewhat nodding ; rays elliptic, longer than the involucre ; ache- 

 nia with 2 — 4 retrorsely scabrous awns. 



Wet places. Can. and throughout the U. S. Aug., Sept. (!)• — Stem 1 — 2 

 feet high, erect or declined at base, branching. Heads rather large, solitary at 

 the end of the branches, erect or somewhat nodding ; rays 8 — 10, bright yellow. 



Large-fiowered Bur-marigold. 



3. B . frondosa Linn. : stem smooth or a little hairy; lower leaves quinate 

 pinnate, upper 3-parted ; the lobes lanceolate, serrate ; heads discoid, pedicel- 

 late, erect ; outer scales of the involucre much longer than the head, ciliate 

 at the base ; achenia 2-awned, somewhat ciliate on the margin. 



Woods and fields. Can. and throughout the U. S. July — Sept.' (T). — Stem 

 2 — 5 feet high, striate, often purple, branched. Heads rather small, on long axil • 

 lary branches or peduncles ; rays none ; disk flowers yellowish. 



Leafy Bur-marigold, 



4. B. connata Muhl. : smooth ; lower leaves often ternate, with the 

 lateral lobes decurrent into a petiole and slightly connate ; upper undivided, 

 oblong-lanceolate, serrate, attenuate at each end ; heads discoid, on short 

 peduncles ; scales of the outer involucre longer than the disk ; achenia 2 — 3- 

 awned. B. tripartita Big. 



Wet grounds. Can. to Geor. W. to Miss. July— Sept. Q.—Stem 1—3 feet 

 high, branched, often purple. Leaves sometimes all undivided. Heads middle- 

 sized, rather erect ; rays none ; disk greenish-yellow. Connate Bur-marigold. 



5. B. bipinnata Linn. : smooth ; stem erect, 4-angled ; leaves petioled, 

 bi-pinnate, the segments lanceolate or oblong-ovate : heads on slender pe- 

 duncles, with 2 — 4 small rays ; outer scales of the involucre speading. about 

 as long as the disk ; achenia linear, 3 — 4-awned. 



Near cultivated grounds. Conn, to Flor. W. to Ark. July — Sept. (I) — Stem 

 2 — 4 feet high, branched. Heads small, oblong, on long terminal and axillary 

 peduncles; rays 3 — 4, small, yellow, obovate ; disA yellow. A troublesome 

 weed, probably introduced from the South. Spanish Needles. 



6. B. Beckii Torr. : stem simple or sparingly branched ; leaves mostly 

 submerged, divided into numerous capillary segments ; the emersed ones 

 few, lanceolate, coarsely serrate or pinnatifidly laciniate ; heads solitary, 

 erect, radiate, terminal ; rays longer than the involucre ; achenia narrow- 

 oblong, 4 — 6-a*?ned. 



