BiDENS. COMPOSITE. 353 



Walt. Car. p. 215. C. perfoliata, Wait. I. c? Helianthus laevis, Linn.! 

 spec. 2. p. 906 {pi. Gronov. .'), not of ed. 2. 



a. achenia 2-awned, sometimes with two other rudimentary awns; rays 

 about twice the length of the inner invohicre. — B. chrysanthemoides, Michx. ! 

 I. c. (wholly?) ; Ell. sk. 2. p. 430 ; DC. ! j^rodr. 5. yj. 595. 



ji. achenia 2-awned ; rays 2-3 times the length of the inner (colored) in- 

 volucre ; exterior involucre not ciliate ; leaves remotely serrulate, scarcely 

 acute. 



y. achenia 3-4-awned ; rays 2-4 times the length of the inner involucre. 

 — B. chrysanthemoides, Bigel.! fl. Bost. ed. 2. p. 294 ; Darlingt. ! fl. Cest. 

 p. 485. B. quadriaristata, DC. ! I. c. 



6. achenia 4-awned ; rays scarcely longer than the inner involucre, often 

 exceeded by the exterior. 



Swamps, and margin of shallow pools, Canada ! and nearly throughout 

 the United States ! (/3. Western Louisiana, Dr. iTaZe/) Aug.-Nov. — ®? 

 Stem 6-30 inches high, branching, rarely a little scabrous or hairy at the 

 summit. Leaves 3-6 inches long, serrate with even acute or mucronulate 

 teeth, often minutely ciliate-scabrous towards the base. Rays golden yellowy 

 usually large (about an inch long) and very showy. Chaff spatulate-linear, 

 scarious, about 3-nerved, colored (yellow or purplish) at the summit. — Beg- 

 gar-Ticks. — The number of awns seems to be constant in each individual, 

 but certainly does not furnish specific distinctions. A specimen sent by the 

 elder Richard to Willdenovv (probably collected by Michaux), presents 

 4-awned achenia. Our var. 6. is a mere state of var. y., and nearly ap- 

 proaches B. cernua. 



5. B. Beckii (Torr.) : glabrous; stem elongated, simple or sparingly 

 branched; leaves chieflv submersed, sessile, many times dissected into ca- 

 pillary segments; the emersed ones few, lanceolate, slightly connate, sharply 

 serrate or incised ; heads solitary on short terminal peduncles; scales of the 

 exterior involucre usually 5, oval or oblong, obtuse, shorter than the interior 

 and somewhat resembling them, several times shorter than the oblong rays ; 

 achenia (immature) narrowly oblong, flattened, perfectly glabrous, 4- (some- 

 times 6-) awned ; the awns approximate in pairs, densely hispid above, gla- 

 brous near the base. — Torr.! in Spreng. neu. entd. 2. p. 135, Sf syst. 3. p. 

 455; Beck. ! bot. p. 207 ; DC! prodr.'b. p. 595. 



In lakes and ponds, and slow-flowing streams, near Schenectady ! and in 

 several localities throughout the western part of the State of New York ! 

 Massachusetts and Vermont, Mr. Oakes ! Near Montreal, Mr. Goldie. 

 Aug.-Sept. — Plant with the habit and submersed foliage of Ranunculus 

 aquatilis, except that the leaves are opposite ; the lowest emersed leaves often 

 1-2-pinnatifid. Scales of the inner involucre oblong-lanceolate, yellowish, 

 with brown stripes. Rays golden yellow, 8-10 lines long. Anthers pale. 

 Branches of the style terminated by a densely hairy rather acutely conical 

 appendage. Awns usually unequal ; the longer nearly twice the length of 

 the half-grown achenium. 



§ 2. Achenia linear-tetragonal, attenuate or rostrate, glabrous or upiwardly 

 hairy. — Psilocarp^a, DC. (Kerneria, Mcench.) 



6. B. leucantha (Willd.) : stem glabrous, somewhat 4-angled ; leaves 

 nearly glabrous, petioled, pinnately 3-5-, the upper ones 3-divided ; the divi- 

 sions ovate or ovate-lanceolate, acute, sharply and closely sen-ate, sometimes 

 confluent; heads (small) paniculate-corymbose, pedicellate; scales of the 

 involucre nearly equal, united at the base; the exterior narrower and ciliate, 

 obtuse ; the interior lanceolate, acute, somewhat scarious and colored, rather 

 shorter than the disk ; rays small, white ; achenia somewhat quadrangular, 



VOL. II. — 45 



