GRAMlNE-fi. (grass FAMILY.) 579 



waste grounds, Florida to North Carolina. July - Sept Q) — Culms l°-2° 

 long. Involucre purplish. 



2. C. tribuloides, L. Involucres whitish, 10-15 in a spike, wedge-shaped 

 at the basf, arnKil above with stout compressed broadly subulate erect or spread- 

 ing s[)iiies ; bristles none ; spikclcts mostly by pairs. — Sands along the coast, 

 Florida, and northward. July - Oct. ® — Culms prostrate, 1° - 2° long. Leaves 

 linear. Spikes l'-2' long. 



52. STENOTAPHRUM, Trin. 



A creeping and branching grass, with the awiilcss spikclcts sunk in excavations 

 of the continuous flattened rachis. Spikclcts by pairs, one pedicellcd and imper- 

 fect, the otlier sessile, and with the structure of raiiicuni. 



1. S. Americanum, Schrank. (Rottboellia dimidiata, Ell) — Damp 

 sandy places along the coast, Florida to South Carolina. June -Sept. y. — 

 Smooth throughout. Culms flattened, creeping, the branches nearly opposite ; 

 flowering culms erect, 6'- 12' high. Leaves 2' -6' long, linear, obtuse, flat or 

 folded, contracted at the base. Spikes lateral and terminal, pcduncled, 2' - 5' 

 long. Sterile spikclet neutral or rudimentary. Fertile spikelet sessile; the up- 

 per glume 7-nervcd, 3 times the length of the lower one. Palca of the sterile 

 flower coriaceous, like those of the perfect one. 



53. ROTTBCELLIA, Brown. 



Erect perennial mostly tall grasses, with flat or channelled leaves and spiked 

 inflorescence. Spikes nearly terete, jointed. Spikclcts awnless, borne by pairs at 

 the base of each joint ; one imperfect, on a coriaceous and closely apprcsscd ped- 

 icel ; the other sessile, embedded in an excavation of the joint, 2-flowered. Glumes 

 2, the exterior one flat, coriaceous, with a hinge-like depression at the base, the 

 interior boat-shaped, membranaceous. Palea; hyaline, 1 - 2 in the staminatc or 

 neutral lower flower, and 2 in the upper and perfect flower. Stamens 3. Styles 

 2. Grain compressed, free. — Spikes solitary on lateral and terminal peduncles 

 or branches. 



1. R. rugosa, Nutt. Culms compressed ; peduncles or branches clustered, 

 short, included in the sheaths of the elongated upper leaves ; spikes spreading, 

 slightly compressed ; sessile spikclet shorter than the joint; lower glume lance- 

 olate, transversely rugose ; sterile flower neutral. — Pine-barren swamps and 

 ponds, Florida to Xorth Carolina. Sept. — Culms 2° -4° high. Spikes green, 

 l|'-2' long, 1" in diameter. 



2. R. COrrugata, Baldw. ? Culm stout, compressed ; peduncles mostly 

 single, elongated; s])ikes slightly compressed, erect; spikclcts longer than the 

 joint; lower glnmc longitudinally grooved and somewhat reticulated, ovate; 

 sterile flower staminatc. — Low pine barrens, Georgia and Florida, near the 

 coast. Sept. and Oct. — Culm 2° -4° high. Spikes 4'-C' long, 2" in diam- 

 eter, purplish. 



3. R. cylindrica. Culmslender, terete; leaves narrowly linear; peduncles 

 single, elongated ; spikes slender, terete, mostly curved ; sjiikclets as long as 



