Genus 74. 



GRASS FAMILY. 



2 35 



i. Erioneuron pilosum (Buckley) Nash. Sharp-scaled Erioneuron. Fig. 564. 



Uralepis pilosa Buckley, Proc. Phila. Acad. Nat. Sci. 1862 : 04. 



1863. 

 Sieglingia pilosa Nash, in Britt. & Br. 111. Fl. 3 : 504. 1898. 

 Erioneuron pilosum Nash, in Small, Fl. SE. U. S. 144. 1903. 



Culms tufted, 2i'-i2' tall, smooth and glabrous, the 

 sterile shoots 4' tall or less. Sheaths smooth, a tuft of 

 hairs on each side at the apex, much shorter than the 

 internodes; ligule a ring of short hairs; blades strict or 

 curved, thick, linear, obtuse, i-nerved, the margins white, 

 serrulate, i¥ long or less, less than 1" wide, folded, at 

 least when dry, pubescent with long hairs, especially be- 

 neath; panicle almost racemose, long-exserted, i'-ii' 

 long; spikelets 3-10, crowded, 8-12-flowered ; empty scales 

 acuminate, I-nerved; flowering scales 3"— 3J" long, acumi- 

 nate, 3-nerved, the midnerve generally excurrent in a short 

 point, all the nerves (the lateral at the top and bottom, 

 the midnerve below the middle), the callus, and the base 

 pilose. 



Dry soil, Kansas to Nevada and Mexico. April-Sept. 



75. TRIPLASIS Beauv. Agrost. 81. 1812. 



Grasses with narrow, flat or involute leaf-blades and contracted or open panicles. Spike- 

 lets shortly pedicelled, 2-6-flowered, the glabrous rachilla articulated between the flowers, 

 the internodes very long. Scales 4-8, membranous, the lower 2 empty, keeled, the flowering 

 scales dorsally rounded at the base, 3-nervedj the lateral nerves pilose, deeply 2-lobed at the 

 apex, long-awned between the lobes, the callus long and subulate, pubescent on the outer 

 surface; palet 2-keeled, the keels long-ciliate. Stamens 3. Styles short, distinct. Stigmas 

 plumose. Grain free, enclosed in the scale. [Greek, referring to the 3 divisions of the 

 flowering scales.] 



Species 3, natives of the eastern and southern parts of North America. Type species : Triplasis 

 americana Beauv. 



i. Triplasis purpurea (Walt.) Chapm. Sand-grass. Fig. 565. 



Aira purpurea Walt. Fl. Car. 78. 1788. 

 Tricuspis purpurea A. Gray, Man. 589. 1848. 

 Triplasis purpurea Chapm. Fl. S. U. S. 560. i860. 

 Sieglingia purpurea Kuntze, Rev. Gen. PI. 789. 1891. 



Culms i c -3° tall, erect, prostrate or decumbent, 

 smooth and glabrous or the nodes pubescent. Sheaths 

 shorter than the internodes, rough; ligule a ring of 

 short hairs; blades l'-2¥ long, 1" wide or less, rigid, 

 scabrous, sometimes sparsely ciliate; panicle i'-3' in 

 length, the branches rigid, finally widely spreading, the 

 lower i'-ll' long; spikelets 2-5-flowered, 2l"-$" long, 

 the joints of the rachilla half as long as the flowering 

 scale; lower scales glabrous; flowering scales oblong, 

 2-lobed at the apex, the lobes erose-truncate, the nerves 

 strongly ciliate, the middle one excurrent as a short 

 point; palets long-ciliate on the upper part of the keel. 



In sand, especially on sea beaches, Maine to Texas, and 

 along the Great Lakes. Also from Illinois and Nebraska 

 to Texas. Plant acid. Aug.-Sept. 



76. REDFIELDIA Vasey, Bull. Torr. Club 14: 133. 1887. 



A tall perennial grass, with long narrow leaf-blades and an ample panicle. Spikelets 

 1-3-flowered, the flowers all perfect. Empty scales 2, about equal, shorter than the spikelet, 

 i-nerved; flowering scales membranous, 3-nerved, with a ring of hairs at the base. Palet 

 2-nerved, shorter than the scale. Stamens 3. Styles long, distinct. Stigmas short, plumose. 

 Grain oblong, free. [In honor - of John H. Redfield, 1815-1895, American naturalist.] 



A monotypic genus of the western United States. Type species : Graphephorum flexuosum Thurb. 



