2 4 



FIELD COLUMBIAN MUSEUM BOTANY, VOL. III. 



Inflorescence panicled, at first included, exserted when mature, 

 of 10 to many (25-30) racemes; axis 2-10 cm. (sometimes 15-20 cm.) 



long, striate, glabrous below, scabrous 

 toward the summit. Racemes erect, 3-13 

 cm. long; rachis 3-angled, hispidulous on 

 the margins. Spikelets usually in pairs, 

 the lower often abortive or wanting, 

 1.15x6 mm. , lanceolate, acuminate. First 

 glume minute, triangular, hyaline -mar- 

 gined, glabrous; second equal to third, lan- 

 ceolate, acuminate, 5-nerved, densely 

 clothed with long, silky, tawny hairs; third 

 4 mm. (excluding hairs), 5-nerved and 

 silky pubescent like the second; floral 

 glume nearly equal to third, chestnut with 

 white margins, papillo-striate, acuminate; 

 palea equal and of like texture. Grain 

 translucent pinkish cream-white, ellipsoid, 

 .7x1.8 mm.; in, section unequally biconvex. 



Hab. Merida 1865, Schott 94 (Panicum lanatum Rottb. Field 

 Col. Mus. Bot. 1:353); frequent at the port of Silam, 3 feet high, April, 

 1895, Gaumer 675 (Panicum insular e G. F. W. Meyer, Field Col. Mus. 

 Bot. 1 1288), San Anselmo 1917 ; on the rocky plain south of the lagoon 

 near Progreso, Millspaugh PL Utowance 1681 {Panicum insulare (L.) 

 Meyer, Field Col. Mus. Bot. 2:25). 



That this species belongs in the genus Syntherisma rather than 

 in Panicum is shown chiefly by the fruiting glumes which are of the 

 form characteristic of the former, having a floral glume with hyaline 

 margins not inrolled. The lanceolate spikelet and minute first glume 

 are also characteristic of Syntherisma. The long, silky pubescence 

 of second and third glumes and more loosely panicled racemes do not 

 seem important enough to differentiate this species generically from 

 Syntherisma. Trichachne Nees (Agros. Bras. 85, 1829), founded on 

 this and allied forms, is, therefore, considered a synonym of Synther- 

 isma. Neither can this species be placed in Tricholcena as by Grise- 

 bach and others, that genus having a distant first glume and a callus 

 below the spikelet, with indurated second and third glumes and 

 membranaceous fruiting glumes about j^ the length of second and 

 third. 



Syntherisma sanguinale (L.) Dulac. Fl. Hautes-Pyr. 77. 



Panicum sanguinale L. 



Digit aria marginata Link. 



Digitaria fimbriata Link. 



Inflorescence digitate or panicled v finally exserted, sometimes 

 much so, of 2-6 racemes; axis 0-4 cm. long (usually i cm. or less), 

 3-angled, hispidulous on the margins. Racemes erect or ascending, 

 sometimes spreading, 3-13 cm. long; rachis flexuous, broadly winged, 

 hispidulous on the margins. Spikelets in pairs, 1.2 x 3.4 mm., oblong- 

 lanceolate, acute. First glume minute, triangular, glabrous; second 

 Y-i the length of the spikelet, ovate-lanceolate, acute, 3-nerved, margins 



