Ordee 155.— CTPERACE^. 743 



2 D. latifolia Baldw. Culm tereteish, stout, 9' to 2f high ; Ivs. iroadly linear, . 

 very long, overtopping the culm ; invol. 8 to 10-leaved, whitish, iecoming dull red I 

 at the base ; aoh. roundish in outline (except the tubercle), roughened, dull, the 

 tubercle broad, conical at top, base 2-horned, decurrent on the edges of tha aoh. 

 with its horns. — Ponds in pine barrens, N. Car. to Pla. 



14. RHYNCHOS'PORA, Vahl. (Gr. pvvxoi;, a beak, oiropd, seed; 

 from the character.) Flowers ^ or 3 5^?, few in each spikelet; 

 glumes loosely imbricated, the lowest small and empty ; perigynium of 

 6 to 12 bristles ; stamens 3 to 12 ; style bifid ; achenium lens-shaped 

 or subglobous, crowned with a tubercle, the distinct, bulbous base of 

 the style. 2C St. leafy, 3-sided. Inflor. terminal and axillary. SetsB 

 hispid (under a strong magnifier). 



§ Setaj densely plumous. Acheninm eubglobons-ovold (terete) Nes. 1, 2 



§ Setie naked, denticulate or hispid. Achenium more or less flattened. (*) 



• Achenium transversely vugous. Betse upwardly bearded, (a) 



a Setffl shorter than the aobeniinn Nos. 8 — 5 



a SetiD equaling or exceeding the achenium. (b) 



b Spikes in drooping panicles. Achenium oblong No, fl 



b Spikes In erect or spreading panicles. Achenium roundish Nos. 7 — 9 



b Spikes corymbous or fasciculate. — Achenium orbicular Nos. 10, 11 



— Acbeniuui oval Nos. 12, IS 



* Achenium smooth and even, (c) 



C Culm and leaves very slender, filiform or setaceous, (d) 



d 8et£B 6 to 10, retrorsely hispid (under a strong magnifier) Nos. 14 — IG 



d SettB 6, upwardly hispid Nos. 17 — 19 



C Calm wiry, firm. Leaves linear, (e) 



e Stamens 8 or 12. Betas 10 or 12 Nos. 20, 21 



e Stamens 3. Setm 6,— retrorsely hispid, hmger than the ach. . .Nos. 22, 23 



— upwardly hispid,- — shorter than the ach. . Nos. 24, 25 



— long as the achenium No. 26 



1 R. plumosa Ell. Culm rigid, wiry, 8' to 2f high ; Ivs. rigid, involute, seta- 

 ceous above, half as long as the culm ; spikes lanoe-ovato, chestnut red, in a ter- 

 minal fascicle, rarely a smaller axillary fascicle below on an exserted peduncle ; 

 glumes broad-ovate, acute ; bristle (setce) 6, densely plumous, as long as the globu- 

 lar-ovoid, rugous achenium ; tubercle short. — Dry pine barrens, N. Car. to Pla 



/3. SEMiPLDMdSA. Setse feathery half way up, naked and denticulate above. — 

 Near N. Orleans (Ingalls. R. semiplumosa Gray., Monog., Ehyn., p. 213). 



2 R. oligdntha Gray. Culm filiform, 8 to 12' high, with one or two filiform- 

 setaceous Ivs. about the same height ; spikes 2 to 6, pedicellate, rarely solitary, 

 lance-ovate, fuscous-red, lateral near the summit of the culm ; glumes ovate, rau- 

 cronate ; setae 6, as long as the ach. and short tubercle, plumous below, hispid 

 above. — N. Car. to Pla., in sandy bogs. 



3 R. cymosa Nutt. CuVm 1 to 2f high, triangular, angles acute ; radical Ivs. linear, 

 shorter than the stem, cauline rising above the stem ; corymbs 3 to 4, the terminal 

 largest ; spikelets ovoid, in close fascicles of about 5 ; glumes broad-ovate, dark 

 brown ; bristles 6, f as long as, the broad ovate, transversely ruguous achenium ; 

 tubercle depressed, much shorter than the achenium. — N. J. to La. Jl,, Aug. 



4 R. Torrey^na Gray. Culm 2f high, teretish, slender, cEespitou.s, striate ; Ivs. 

 setaceous, the radical 6 to 10" long, cauline much shorter ; corymbs few-flowered, 

 the lateral, if any, on capillary peduncles ; spikes ovoid, pedicellate or sessile ; 

 glumes ovate, mucronate, brown ; bristles 6, scarcely half as long as the oblong- 

 ohovate achenium ; tubercle short, nearly as broad at base as the achenium. — ^N. 

 J. JL, Aug. (Holton.) 



5 R. rarifldra EIL Culms tufted, 6 to 16' high, filiform, with much shorter, seta- 

 ceous leaves ; spikes lanceolate, fuscous, near 2" long, pedicellate, few in 2 or 3 

 loose, simple, corymbous panicles terminal and lateral ; bracts capillary ; glumes 

 ovate, acute ; setse about 6, nearly as long as the strongly rugous, roundish obo- 

 vate achenium ; tubercle very short. — S. Car. to Pla. and La,, in bogs. Has the 

 aspect of a Trichelostylis. 



6 R. inexpdnsa Vahl. Culm slender, teretish, rather rigid, 1 8' to 3f high ; Iva 

 narrowly linear, flat, smooth, half as long as the culm ; spikes lanceolate, fusooua, 

 about 3" long, 3 to 5-flowered, forming several axillary and terminal, rather long. 



