GRAMINEJE. (GRASS FAMILY.) 579 
waste grounds, Florida to North Carolina. July- mess (0 — Culms 19-29 
long. Involucre purplish. 
2. C. tribuloides, L. Involucres whitish, 10- 15 in a spike, wedge-shaped 
at the base, armed above with stout compressed broadly subulate erect or spread- 
ing spines; bristles none; spikelets mostly by pairs. — Sands along the coast, 
Florida, and northward. July- Oct. @—Culms prostrate, 19 — 2? long. Leaves. 
linear. Spikes 1'— 2' long. : 
52. STENOTAPHRUM, Trin. 
A creeping and branching grass, with the awnless spikelets sunk in excavations 
of the continuous flattened rachis. Spikelets by pairs, one pedicelled and imper- 
fect, the other sessile, and with the structure of Panicum. 
1. S. Americanum, Schrank. (Rottbellia dimidiata, Ell.) — Damp 
sandy places along the coast, Florida to South Carolina. June- Sept. | — 
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, peduncled, 2'- 5/ 
long. Sterile spikelet neutral or rudimentary. Fertile spikelet sessile; the up- 
per glume 7-nerved, 3 times the length of the lower one. pus of m sterile 
lover egit ile EU HN M QU MER um rad 
53. ROTTBŒLLIA, decus. 
Erect seid mostly tall grasses, with flat or channelled leaves and spiked 
inflorescence. Spikes nearly terete, jointed. Spikelets awnless, borne by pairs at 
the base of each joint; one imperfect, on a coriaceous and closely appressed 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. Pales hyaline, 1-2 in the staminate 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 spikelet shorter than the joint; lower glume lance- 
olate, transversely rugose; sterile flower neutral. — Pine-barren swamps- and 
ponds, Florida to North Carolina. Sept. — Culms 20—40 ‘high. Spikes green, 
1j! - 2/ long, 1" in diameter. 
2. R. corrugata, Baldw.? Culm sto, ood: peduncles mostly 
single, elongated; spikes slightly compressed, erect; spikelets longer than the 
joint; lower glume longitudinally grooved and somewhat reticulated, ovate ; 
sterile flower staminate.— Low pine barrens, Georgia and Florida, near the 
coast. E n r- 49 ga d fasce 4!— 6 long, 2” in diam- 
