HITCHCOCK—MEXICAN GRASSES. 921 
60 to 70 cm. high, glabrous, the lower nodes and especially those of the young shoots 
spreading-villous, the upper nodes glabrous or nearly so, the internodes rather con- 
spicuously yellow; sheaths shorter than the internodes, retrorsely villous toward the 
base; ligule about 2 mm. long, extending down the sheath as a scarious margin; 
blades ascending or the lower spreading, flat, 3 to 6 cm. long, about 2 mm. wide (the 
uppermost sometimes reduced to a mere tip), more or less scabrous on both surfaces, 
the lower sometimes sparsely pilose; inflorescence finally long-exserted, consisting 
of 2 to 4 slender ascending racemes 6 to 11 cm. long, usually naked at the base, the 
rachises very slender, triangular, scabrous on the angles; spikelets in pairs (or the 
upper and lower solitary), one short-pediceled, the other on a slender pedicel about 
as long as the lower spikelet, the pairs subdistant; spikelets 3 mm. long, about 1 
mm. wide, acuminate; first glume subhyaline, less than 0.5 mm. long; second glume 
and sterile lemma glabrous, 7-nerved, exceeding the fruit, the glume slightly longer 
than the lemma; fruit 2.5 mm. long, bluish lead color except the rather broad white 
hyaline margin. 
Type in the U. 8. National Herbarium, no. 691225, collected ‘‘on the bank of a 
large pond, 1,800 meters altitude, Orozco, Jalisco, Mexico, September 29, 1910,” by 
A. 8. Hitchcock (no. 7376). 
The only other specimen seen is from the same locality, growing ‘‘in and near the 
water,’ Hitchcock 7372. 
Syntherisma distans differs from S. aequiglumis (Hack. & Arech.) Hitchc. in its more 
stoloniferous habit, much scantier foliage, fewer, longer, and more slender racemes, 
and the glabrous, less acuminate, more distant spikelets. Notwithstanding its being 
nearly glabrous, it is probably more nearly related to S. velutina than to the S. san- 
guinalis group to which S. aequiglumis belongs. 
5. Syntherisma digitata (Swartz) Hitchc. Contr. U. 8. Nat. Herb. 12: 142. 1908. 
Milium digitatum Swartz, Prodr. Veg. Ind. Occ. 24. 1788. 
Digitaria setosa Desv.; Hamilt. Prodr. Fl, Ind. Occ. 6. 1825. 
Type locality, ‘““Jamaica.’’ 
RANGE: Tropics and subtropics of the western hemisphere. 
HERBARIUM SPECIMENS FROM MEXICO: 
Tamautieas: Tampico, Palmer 145 in 1910; low brushy land, Hitchcock 5780. 
Couma: Jala, along railway, Hitchcock 7009, Caldras, along railway, Hitchcock 
7017. Alzada, upland prairie, Hitchcock 7069. Colima, Orcutt 4541. 
Veracruz: Veracruz, sandy prairie, Hitchcock 6566. 
GueERrRERO: Balsas, gravel along railway, Hitchcock 6778, 6809. 
Cutapas: Ocuilapa, table-land, Nelson 3049. 
6. Syntherisma sanguinalis (L.) Dulac, Fl. Haut. Pyr. 77. 1867. CRAB GRASS. 
Panicum sanguinale L. Sp. Pl. 57. 1753. 
Type locality, ‘‘Habitat in America, Europa australi.”’ 
Rance: Temperate and warmer regions of the world. 
HERBARIUM SPECIMENS FROM MEXICO: 
LowER CALIFORNIA: San José del Cabo, Brandegee 17, 29, 41. Santa Agueda, 
Palmer 222 in 1890. Sierra de San Francisquito, Brandegee 26. 
Sonora: Guaymas, Palmer 48, 269, and 695 in 1887; weed in park, IMitcheock 3570, 
Hermosillo, cultivated soil, Hitchcock 3588. Yaqui River, Palmer 3 in 1869. 
Alamos, Palmer 685 in 1890. Sierra de Alamos, Rose, Standley & Russell 
12983. 
CHIHUAHUA: Southwestern Chihuahua, Palmer 110f in 1885. Sanchez, along 
railway, Hitchcock 7695. 
StwaLoa: Imala, in dense patches along river banks, Palmer 1757 and 1764 in 1891. 
Topolobampo, Palmer 234 in 1897, Rose, Standley & Russell 13277. Mazatlan, 
dry hill, Rose, Standley & Russell 13675; old field: Rose, Standley & Russell 
