296 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Sandy woods, southeastern United States and Cuba (La Grifa la Catolina, 

 Wright 3884). Originally described from South Carolina. 



12. Syntherisma argillacea sp. nov. 



A cespitose perennial ; culms ascending, slender, branching from the lower 

 nodes, glabrous, 15 to 60 cm. tall, the nodes sparsely pilose; leaves mostly 

 clustered toward the base, olivaceous, the sheaths and upper surface of the 

 blades scabrous, usually rather densely papillose-pilose (sometimes scabrous 

 only), the lower surface of the blades sparsely so; ligule membranaceous, about 

 0.5 mm. long ; blades flat, ascending, 3 to 8 cm. long, 3 to 4 mm. wide, tapering 

 from base to apex; panicle long-exserted, of 1 to 6 (usually 3 or 4) ascending 

 racemes, the common axis 0.5 to 4 cm. long, scabrous on the angles, short- 

 villous in the axils ; racemes 1 to 8 cm. long, the slender wingless zigzag rachis 

 scabrous on the angles; spikelets in pairs (rarely in 3's) on slender scabrous 

 pedicels, 2 mm. long (or the hairs slightly exceeding 2 mm.), 0.8 mm. wide; 

 first glume an obscure hyaline rudiment or wanting ; second glume about three- 

 fourths the length of the sterile lemma, the margins and internerves of both 

 (except the middle pair of the lemma) densely clothed with thick glistening 

 hairs, some as much as 1 mm. long, exceeding the spikelet as a brushlike tip; 

 fruit dark brown, 1.7 to l.S mm. long, 0.7 mm. wide, fusiform, the hyaline 

 lemma margins meeting over the upper half of the palea. 



Type in the U. S. National Herbarium, no. 732423, collected on shaded rocks 

 along a trail, Monte Alegrillo, near Maricao, Porto Rico, at an altitude of 800 

 meters, October 20, 1913, by Agnes Chase (no. 6221). 



Probably most nearly related to Spntherisma leucocoma and 8. panicea, 

 from both of which it differs in the short, flat blades. The long hairs of the 

 smaller spikelets are thicker and stiffer than in the spikelets of S. leucocoma 

 and longer than in those of S. panicea. 



Clay soil, Cuba (Herradura, Tracy 9104; near Minas, Ledn 4785; Guana- 

 bacoa, Ledn 4715; Manacas, Leon 5843), and Porto Rico (Maricao, Chase 6221; 

 Monte Mesa, Chase 6271, 6277). Ha^ti & L^ — 



29. THRASYA H. B. K. 



Inflorescence a single terminal spikelike raceme, the rachis with mem- 

 branaceous wings, partially embracing the row of spikelets; spikelets appar- 

 ently subsessile and solitary in a single row, but actually in pairs, the spikelets 

 of each pair back to back, the pedicel of the primary spikelet adnate to the 

 midnerve of the rachis ; first glume minute, often hyaline ; second glume shorter 

 than the spikelet; sterile lemma subindurate, thinner down the middle, at 

 maturity splitting to the base, the margins of the split rolling inward, the 

 sterile palea nearly as long as its lemma, the margins firm, inclosing a staminate 

 flower or empty ; fruit cartilaginous-indurate, commonly with stiff hairs at the 

 summit. 



Rachis ciliate with stiff hairs ; blades pilose, at least on the margin. 



1. T. paspaloides. 

 Rachis not ciliate ; blades glabrous or nearly so . 2. T. robusta. 



1. Thrasya paspaloides H. B. K. Nov. Gen. & Sp. 1 : 121. pi. 39. 1816. 



Panicum thrasya Trin. Mem. Acad. St. Petersb. VI. Sci. Nat. 3 Z : 228. 1834. 



A slender, erect, densely tufted perennial, 25 to 50 cm. tall, at length branch- 

 ing from the upper nodes, with narrow flat pilose blades and long-exserted 

 arcuate racemes 3 to 5 cm. long, the spikelets stiffly ciliate. In referring the 



