MANUAL OF THE GRASSES OF THE WEST INDIES Buy 
floret is often longer and the lemma less convex than when fertile, 
the spikelets on the same panicle thus having a somewhat diverse 
appearance. 
Florets appressed-pubescent. 
iPiadessoveue-claspinige - Ui) TCs eee Bd 1. I. POLYGONOIDES. 
Blades tiimeay, oo oie eke Lae = Gein ee AS 2. I. LEERSIOIDES. 
Florets glabrous, or the palea minutely hispidulous. 
Panicle contracted, spikelike, not more than 3 cm long, the branches appressed 
or the lower sometimes ascending; plants low and spreading__3. IJ. PYGMABA. 
Panicle open, the branches spreading or ascending. 
Blades about 3 mm wide, thick, rigid, pungent, with conspicuously thickened 
POTTS Der] Oude ses AMER le Jae RA GR Se NaI cha cll Sa ial 4, I]. RIGIDIFOLIA. 
Blades mostly 5 to 20 mm wide, firm but not pungent nor with thickened 
midrib. 
Plants trailing; blades rarely more than 5 cm long______-__ 5. I. RIGENS. 
Plants clambering; blades mostly more than 5 cm long. 
Glumes pubescent; blades firm, not more than 12 cm long and 1 cm 
SWwaGleod Fryar Ate unt pe! Chee id hearty) wasn Ao te)» 6. I. ANGUSTIFOLIA. 
Glumes glabrous (rarely obscurely pubescent at the tips); blades 
mostly more than 15 cm long and 1.5 cm wide. 
Spikelets aggregate toward the ends of the branches and branchlets. 
. I. ARUNDINACEA. 
Spikelets not aggregate; panicle loosely flowered____8. I. DISPERMA. 
1. Isachne polygonoides (Lam.) Doell, in Mart., Fl. Bras. 27: 273. 
ISAT 
Panicum polygonoides Lam., Encycl. 4: 742. 1798. Cayenne. 
Apparently annual; flowering shoots 20 to 30 cm tall, erect from a 
long creeping, freely branching culm, rooting at the nodes, the whole 
plant often a meter in length, the erect shoots finally bearing fascicled 
branchlets; sheaths hispid; blades spreading, lanceolate-ovate, very 
scabrous; panicles included at base, about 5 cm long and as broad, 
loosely many-flowered. 
This is distinguished from all others of the West Indies by the 
ovate clasping blades and by the dissimilarity of the two florets. 
Moist ground, often in water, British Honduras and Guatemala to 
Trinidad and Brazil; Cuba, Hispaniola. 
Cusa: Isla de Pinos, Ekman 11702. 
Dominican ReEpusiic: Cotuy, Abbott 748. Jarabaco, Ekman H 
14139. Villa Altagracia, Ekman H 11222. Sanchez, Ekman H 
14718. Tomas, Ekman H 13020. 
Trinipap: Piarco Savanna, Britton and Hazen 704; Hitchcock 
10362 (Amer. Gr. Nat. Herb. 598). 
In the Florence Herbarium there is a specimen of this species said 
to be collected by LeDru in Puerto Rico. No other specimen from 
that island has been seen. 
2. Isachne leersioides Griseb., Mem. Amer. Acad. (n. s.) 8: 533. 
1862. Cuba, Wright 755. 
Culms slender, branched, trailing, glabrous, striate, 1 to 2 m long; 
sheaths on the main culms much shorter than the elongate internodes, 
overlapping on the flowering branches, appressed papillose-hispid or 
nearly glabrous; ligule a very short membrane, ciliate with stiff hairs 
about 1 mm long; blades linear, ascending, rather firm, 5 to 15 cm 
long, 0.5 to 4 mm wide, long-acuminate, cartilaginous-margined, 
scabrous or hispidulous on both surfaces; panicles terminating the 
branches, ovoid or oblong, 5 to 15 cm long, as much as 7 cm wide, 
the branches mostly single, rather stiffly ascending or spreading, 
