4 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Panicum alsinoides Griseb. Fl. Brit. W. Ind. 550. 1864. " Hab. Jamaica!, 

 March; St. Kitts ! ; Trinidad ! Pel." The description applies to Ichnanthus ten- 

 uis, but the specimen (sterile) in the Gray Herbarium collected in Jamaica by 

 March is Oplismenus setarius. Ichnanthus tenuis is not known from Jamaica. 

 The specimen of P. alsinoides in the Grisebach Herbarium from St. Kitts is 

 also sterile and is probably not Ichnanthus tenuis. 



Ichnanthus alsinoides Munro ; Hemsl. Biol. Centr. Amer. Bot. 3: 500. 1885. 

 Based on Panicum alsinoides Griseb. 



Ichnanthus tenuis Hitchc. & Chase, Contr. U. S. Nat. Herb. 18: 334. 1917. 

 Based on Oplismenus tenuis Presl. 



DESCRIPTION. 



Apparently annual ; culms slender, spreading or creeping, rooting at the 

 nodes, much branched, the fertile shoots ascending, 10 to 20 cm. high, glabrous 

 or puberulent mostly in lines, purplish ; sheaths shorter than the internodes, 

 papillose-hispid with weak hairs ; blades lanceolate, 2 to 5 cm. long, 4 to 10 mm. 

 wide, sessile, rounded or slightly cordate at base, acute or acuminate, thin, 

 glabrous or puberulent, often sparsely hispid, the margins scabrous : panicles 

 terminal and axillary, 2 to 4 cm. long, or the axillary ones smaller, mostly on 

 long slender peduncles, the few branches rather weakly spreading, as much as 

 2 cm. long, the axes slender, angled, scaberulous, and sometimes puberulent, 

 often villous or with a few long hairs at the base of the branches; spikelets 

 narrowly lanceolate, 3 mm. long, acuminate, hispid, the pedicels slender, un- 

 equal, the shorter one of the pair 1 mm. long or less, the other twice or thrice 

 as long ; first glume broad and clasping at base, nearly as long as the spikelet, 

 attenuate into a slender point, glabrous or scaberulous ; second glume and sterile 

 lemma nearly equal, acuminate, the former attenuate-pointed, prominently 

 nerved, sparsely hispid along the lateral nerves, the sterile palea small and 

 narrow ; fertile lemma 1.5 to 2 mm. long, dorsally compressed, oblong, rounded 

 at the apex, the margins flat, widely separated, the scar about 0.3 mm. long, 

 extending downward into a wing decurrent on the short stipe. 



DISTRIBUTION. 



Damp shady places, Guatemala to northern South America. 

 Guatemala: Cubilquitz, Tiirckheim 8799 (abnormal). Coban, Tiirckheim 908 



( abnormal ) . 

 Costa Rica : Alajuela, Jime'nes 164, 165, 701, 705. Boruca, Tonduz 3363, 4460. 



Buenos Aires, Tonduz 3647. Piedro del Convento, Pittier 3654. Rio 



General, Pittier 3359, 3363. 

 Panama: Gatfin, Hitchcock 9186. Culebra, Pittier 2119; Amer. Or. Xat. Herb. 



581; Hitchcock 9166. Chagres, Fendler 373 (abnormal). El Boquete, 



Hitchcock 8274 (abnormal). Cerro Vaca, Pittier 5366, 5370. Balboa, 



Hitchcock S000 (abnormal). Bohio, Hitchcock 8394 (abnormal). Anc6n, 



Killip 4029. 

 Trinidad: Maraval, Broadioay 4912, 4913. Arima, Hitchcock 10313. Port of 



Spain, Hitchcock 10052, 10199. St. Joseph, Amer. Gr. Nat. Herb. 5S0. 

 Colombia : Santa Marta, Smith 2129, 2135, 2572. 

 Venezuela: Tovar, Fendler 2532, 2544 (abnormal). 



Explanation op Plate 2.- — Ichnanthus tenuis. Specimen from Rfo Grande, Panama, 

 Pittier 2119 (U. S. Nat. Herb. no. 975195) ; also a branch with proliferous spikelets, 

 collected between Bohio and Frijoles, Panama, Hitchcock 8394 (U. S. Nat. Herb. no. 

 940903). Both natural size. 



