718 GRAMINEiE impeeata 



PASPALUM 



Sbbobdbb I PANICACE^ E.;Br. Verm. Schr. i, 114. 



Spikdlets one- or two-flowered, when two-flowered the second or 

 terminal ope is perfect and the lower one staminate or neutral. 

 Racbielia articulated below the empty glumes the spikelets falling 

 from the pedicels entire either singly or in groups or witl\ the 

 joints o^ an articulated rachis. 



Trilbe 1 Andropogoneoe. Spikelets in spike-like racemes,^ at 

 each joint of an articulated rachis, one sessile and hermaphrodite, the 

 other pedicellate and either hermaphrodite, staminate,- neutral or ' 

 or reduced to the pedicel only, glumes usually 4, thejirst>2 empty] 

 large^ and muchfirmer in texture [thctnlthelothers; the third usually 

 with a ^taminate flower in its axil; the fourth hyaline vlith a fertile 

 flower in its axil, usually awnkd. Awn usually twisted or geniculate. 



1 IMPEEATA Cyrill pi. Bar. Ic. ii, 26. (1796.) 



Panicle spike-like. Spikelets in pairs on unequal short clavate 

 pedicels or one sessile, both perfect, awnless. Outer empty glumes 

 clothed with long white silky hairs: third and fourth glumes and 

 paletihyaliifte. Stamens 1 or ^. Stigmas 2. i 



I. Bookeri Kupr. CEfvers Vet. Acad. Stockh. 160. Stems 2^4 feet 

 high, aimple, Bmootb, from creeping rootstocks: radical leaves 4-l2'tncheB 

 long, the caDline shorter, decreasing upward : ligule short, ciliate : paniclb 

 nearly cylindrical, erect, 6-12 inches long, sometimes interrupted below: 

 hairs ^ense, straight, about J^ inch long, giving the peculiar leathery ap- 

 pearance^ JJeqked with the yellow or brown anthers and stigmas. Along 

 8treaij(^, eastern Oregon and Nevada to California and Texas. 



Tribe 2 Panicese. Spikelets hermaphrodite, terete or flattened 

 on the.bacK Gluines 2-%, when 4 there is sometimes a staminate 

 flower or palea in the axil of the third. Axis of the inflorescence not 

 articula,ted; the rachella being articulated below the glumes, the 

 spikelets falling off singly from their pedicels. 



5 PASPALUM L. Syst. ed. 10, ii, 855. 



Spikes or racemes either solitary, few and digitate or many and 

 panicled. Spikelets in 2-4 rows upon one side of a flattened or 

 filiforn^ jointlpss rachis, jointed upon their short pediqcils, plano- 

 convex, a\»fn|ess, apparently one-flowered. Glurnes 2, nearly 

 equal, rew-nerved. Flowering glumes roundish or ovate^jcoria- 

 ceous, convex and enclosing the palet. Scales 2. StameQS 3. 

 Ovary Smooth. Grain enclosed in the glume. 



F. djisticham L. Amceh. Acad, v, 391.. - Rootstock widely creeping-, 

 perennial: stems 6-lS inches high, clothed below with the' somewhat 

 crowded sheaths: leaves flat, 2-3 inches long, glaucous, rough above: 

 spikes 2, spreading, cnie' sessile, the other peduncled, 1-1}^ inches long; 

 denseily flowered: spikelets in 2 rows, ovate, acute, 1% lines long;, glbmes 

 3-nerved, more or less pubescent. In moist meadows Oregon to Calif6rnia 

 and the.aoutb^rn Atlantic States : also. in Europe. :. 



3 PANICUM L, Sp. 55. 

 Spikelets 1- or .2-flowered, when 2-flowered the lower one gta. 



