134 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Fig. 129.— P. costaricense. 

 From type specimen. 



76. Panicum costaricense Hack. 



Panicum costaricense Hack. Oesterr. Bot. Zeitschr. 51:428.1901. "Costarica: 

 Inter Buenos Aires et Terraba (Pittier 3636); in silva prope Terraba (3673), in vir- 

 gultis ad Rio Ceibo (4860)." The first specimen cited, which is taken as the type, is 

 in the Brussels Herbarium, and was examined by Hackel, but is not in his own herba- 

 rium. The two other specimens are in Hackel 's herbarium. 



DESCRIPTION. 



Plants apparently annual; culms slender, erect, 0.5 to 1 meter high, sparingly 

 branched, striate, glabrous or minutely pubescent; sheaths much shorter than the 

 elongated internodes, papillose-pilose to glabrate, ciliate at 

 least toward the summit; ligules membranaceous, ciliate, 

 about 0.5 mm. long; blades 5 to 10 cm. long, 6 to 12 mm. 

 wide, narrowed toward the base, long-acuminate, very sparsely 

 pilose on both surfaces or glabrate; panicles ovoid in outline, 

 10 to 15 cm. long, about two-thirds as wide, loosely flowered, 

 the slender, flexuous branches ascending or spreading, bear- 

 ing delicate branchlets throughout, the scattered spikelets 

 on capillary, flexuous pedicels; spikelets 2.4 mm. long, 0.7 

 mm. wide, elliptic, acute, rather strongly nerved; first glume 

 nearly half the length of the spikelet, acute, hirsute toward 

 the margin ; second glume and sterile lemma sub qual, pointed 

 beyond the fruit, hirsute toward the margin and with very minute papillae bordering 

 the nerves; fruit 1.7 mm. long, 0.6 mm. wide, elliptic, smooth and shining, the 

 margins of the lemma near the base each bowed out into a little angle, giving a 

 somewhat auricled appearance. 



The somewhat auricled base of the fruit in this species suggests an approach to 

 species of Ichnanthus. 



DISTRIBUTION. 



Forests, Costa Rica. 



Costa Rica: Buenos Aires, Pittier 3661, Tonduz 4860; Cordoncillal, Pittier 3640; 

 Boruca, Pittier 4626; Terraba, Tonduz 3673. 

 Panicum expansum Fourn., ft the type specimen of which, Liebmann's no. 426 from 

 Huitamalco, Mexico, in the Copenhagen Herbarium, was examined at Halle, is appar- 

 ently closely related to P. costaricense. The fruit has the same auricled or angled base, 

 but the spikelets are slightly larger and glabrous, and the blades are glabrous. Lieb- 

 mann's no. 427 in the same herbarium is the only other specimen of this species we 

 have seen. For the satisfactory placing of this species more material is needed. 



77. Panicum parvifolium Lam. 



Panicum parvifolium Lam. Tabl. Encycl. 1: 173. 1791. The only specimen men- 

 tioned is "Ex Amer. merid. Communic. D. Richard." The type, in the Lamarck 

 Herbarium, labeled, "ill. gen. ex D. Richard," is a single slender culm. 



Panicum brasiliense Spreng. Syst. Veg. 1: 321. 1825. u Brasil. (P. ascendens W. 

 herb.)" In the Willdenow Herbarium is a specimen of P. parvifolium labeled, 

 "Panicum adscendens. Brasil. Hoffmansegg," which is evidently the specimen 

 referred to by Sprengel, and is the type of P. brasiliense. 



Panicum ascendens Willd.; Spreng. Syst. Veg. 1: 321. 1825. This is given as a 

 synonym of P. brasiliense of which it is a typonym. 



Panicum adscendens Hoffmgg.; Ind. Kew. 2:410. 1894. This is listed with the 

 reference "ex Schult. Mant. 2: 592," but this is evidently an error, since the Mantissa 



«Mex. PI. 2: 26. 1886. 



