NATURAL SCIENCES OF PHILADELPHIA. 91 



Agrostis albicans, s. n. Culmo erecto glabro simplici subgeniculato, 

 2 3 pedali ; foliis planis glabris 4 5-policaribus ; vaginis internodio breviori- 

 bus ; ligulis ovatis lanceolatis acutis aut apice fissis ; panicula interrupta 

 subcoarctata elongata 5 9-policari ; radiis lateralibus confertis insequalibus 

 scabriusculis densifloris ; glumis sequalibus aut parum insequalibus lance- 

 olatis acutis dorsis scabris viridescentibus lateralibus albo-hyalinis ; valvulis 

 hyalinis subacutis gluma | brevioribus callo nudo ; receptaculurn nullum. 



Oregon, Columbia Woods. Nuttall. 



Intervals between brandies of the panicle \ 1 inch long and the branches 

 1 1J inches long; panicle greenish white. 



Muhlenbergia a r e n i c o 1 a, s. n. Radice fibrosa culmo erecto tereti glabro 

 12 18-policari; foliis linearibus convolutis 2 6-policarisbus ; vaginis inter- 

 nodium aaquantibus aut excedentibus striatulis glabris ; ligulis membranaceis 

 linearibus acutis vel laciniatis 4 6 lin. ; paniculis terminalibus diffusis ; 

 radiis capillaribus ramosis ; glumis subaequalibus scabriusculis acutis valvula 

 brevioribus, inferiore breviter aristata ; valvulis sequalibus inferiore breviter 

 aristata. 



Arid places in Western Texas. 



Stem leaves few and also the radical leaves, which are short ; panicle 

 spreading, its lower branches 3 4 inches in length, which have branchlets 

 48 lines long, with 3 6 flowers on pedicels 5 10 lines in length ; pedicels 

 one- flowered ; valves about twice the length of the glumes, with bristles 2 4 

 lines long. 



Muhlenbergia monticola, s. n. Caule ramoso decumbente glabro ; foliis 

 convolutis2 4-policaribus ligula 4 6 lin. tissa vel integerrima ; panicula co- 

 arctata basi inclusa glumis insequalibus acutis valvula brevioribus ; paleis 

 insequalibus scabrosis basi pilosis, inferiore longe aristata. 



Northwestern Texas. 



Stems 1 1J feet long ; lateral branches with small, slightly exserted pani- 

 cles ; awns 3 4 times longer than the ; brownish red valves ; lower 

 valve linear, J shorter than the upper, and gradually elongated into the awn ; 

 some of the pairs of valves are nearly equal in length ; panicles 34 inches 

 long ; upper glume \ shorter than the upper valve ; glumes equal, or the 

 lower J shorter ; keels green and scabrous, sides hyaline. 



Muhlenbergia p a u c i f 1 o r a, s. n. Culmo subdecumbente 12 18-poli- 

 cari ; foliis convolutis apice setaceis glabriusculis ; vaginis internodio parum 

 brevioribus ; ligulis membranaceis linearibus subobtusis ; paniculis 2 3-poli- 

 caribus interruptis paucifioris ; glumis ovatis acutis sequalibus subcarinatis 

 valvula | brevioribus ; valvulis lanceolatis inferiore valde 3-nervia et longe 

 aristata ; spiculis rufescentibus ; carinis et nervis subviridescentibus. 



Hill sides, Western Texas. 



Panicle terminal, with short appressed branchlets of 4 6 flowers, each of a 

 brownish red color ; bristles longer than the flowers. 



Muhlenbergia T e xa n a, s. n. Culmo erecto ad basin decumbente gracile 

 (4 6-policari) tereti ; foliis subsetaceis scabriusculis ; vaginis internodio 

 brevioribus 6 12 lin. longis convolutis ; panicula elongata 4 5-policari 

 lucida patula ; radiis alternatis capillaribus 3 5-floris ; spiculis minutis ovatis 

 acutis ; glumis pilosis sequalibus valvula parum brevioribus ; valvulis lance- 

 olatis acutis subsequalibus, inferiore in aristam flosculo parum breviorem 

 terminata ; caryopsi lineari-ellipsoidea subobtusa glabra palea breviore. 



Northern Texas. Maj T . 



Roots small and fibrous ; culms 12 inches long, scabrous, terminated by 

 the elongated open panicle ; lateral panicles small, scarcely exserted from the 

 sheaths of the lower leaves. 



1862.] ' 



