784 OEDEK 156. GRAMINE^E. 



pale of a second (abortive) flower, the upper ,pale and the lower glumo 

 being obsolete.) Inflor. an open panicle. 



M. effusum L. Culm upright, simple, smooth, 3 to 6 or 8f high ; Ivs. flat, 8 to 

 12' by 6"' to 1', oa smooth, striate sheaths; branches of the panicle clustered, 

 spreading, remote ; spikelets ovate, few and scattered, acute, about 1" long. In 

 woods, Penn. to Can. and Wis. Plant pale green. Summer. 



17. AMPHICAR'PUM, Kunth. (Gr. cpfo, both or twain, KapTroc, 

 fruit.) Spikelets (apparently) 1-flowered and perfect as in Millium, br.t, 

 of 2 kinds, terminal, deciduous and sterile, the radical fertile ; glumes 

 2, lanceolate, acute, awnless, as long as the 2 coriaceous pales ; stamens 

 3 ; stigmas 2, plumous, purple. 2|! Caespitous, erect, strict, with erect, 

 lance-linear Ivs., the terminal fls. in a strict, contracted, slender panicle, 

 the radical fls. are each solitary, on a slender ped., and subterranean. 



A. Purshii Kunth. Pine barrens, N". Jer. (Long-a-coming, Jackson). Culm 2f 

 high, glabrous. Lvs. 2 to 3' by 2 to 3", hairy, as well as the sheaths, the upper 

 sheath long and without a leaf. Pan. on a long, exserted ped. Spikelets lij'' 

 long, the radical ones 2'', veiny, the glumo clasping the longer, neutral, single 

 pale. Aug. (Millium Amphicarpon Ph.) 



18. PAN'ICUM, L. PANIC GRASS. (Lat. panicula, the mode of 

 flowering, or pa-nis, bread, which some species afford.) Glumes 2, un- 

 equal, awnless, the lower much smaller ; flowers 2, dissimilar, the lower 

 abortive or sterile, with 1 or 2 pales, the upper pale membranous ; the 

 upper i with the pales cartilaginous, polished, equal, concave, awnless, 

 coating the caryopsis ; stamens 3 ; stigmas plumous, purple. Differs 

 from Paspalum in the presence of the lower (true) glume. Panicles 

 simple or compound. 



Spikelets acute or pointed, very mimerons, Tscemed in large panicles. (*) 



* Abortive flower neutral, consisting of a sinjrle palea. (a) 



a Panicle capillary, with the spikelets solitary Nos. 1, 2 



a Panicle not capillary, dense-flowered No. S 



* Abortive flower neutral, consisting of 2 palea) (pales), (b) 



b Panicle contracted, eylindric. Upper glume gibbous No. 4 



b Panicle open. Gluuie 8-veined. The 2 pales equal No. 5 



Gluuie 5 to T-veined, longer than abortive flower Nos. 6, 7 



shorter than abortive flower , No. S 



* Abortive flower staminate, with 2 pales. Tall, very smooth Nos. 9,10 



Spikelets obtuse or barely acute, solitary, pedicellate, not numerous. (**) 



** Abortive flower (neutral) consisting of a single pale Nos. 1113 



** Abortive flower of 2 pales, the upper small and scarious. (c) 

 C Leaves narrow, obscurely veined, 1 to 5" wide, (d) 



d Spikelets densely fringed with silky hairs ; fertile flower colored No. 14 



d Spikelets glabrous or sparsely pilous ; fertile flo-wer white, (dd) 



dd Spikelets less than 1" long, roundish or oval : glume 5-veined.. .Nos. 15, 16 



dd Spikelets 1 to' 1}" long, oval; glume 9-veinea Ns. 17, 18 



C Leaves broad, conspicuously veined, 5 to 20 // wide, (e) 



e Abortive flower usually staminate with 3 stamens r Nas. 18, 19 



e Abortive flower eutraJ T never with stamens, (f ) 



f Plant very downy, with soft, dense, velvety hairs No. 20 



f Plant smoothbh or pilous-ciliate, branched or simple Nos. 21, 22 



Spikelets barely acute, in short (I'), dense, secund, alternate spikes. Southern,.... Nos. 23, 24 



1 P. capillare. Culm nearly - simple, assurgent and thick at base, 1 2f; Ivs. 

 hairy, broad-linear, acuminate, 4 6' long ; sheaths covered with bristly hairs ; pan. 

 large, pyramidal, capillary, loose, expanding; spikelets small (" long), often pur- 

 ple, oblong-ovate, purple, lanceolate, acuminate, smooth, on long, hispid peduncles; 

 abortive fl. of 1 palea. (D Fields and roadsides, U. S. and Can. Aug. Pani- 

 cles often If or more long, with a very light, airy appearance. In poor or shady 

 soils it is much reduced. 



2 P. autumn&le Bosc. Culm very slender, assurgent, 10to20f high; fcs. gla- 

 brous, lance-linear, at length convolute. 2 to 3' long; sheaths glabrous; pan. dif- 

 fuse, bearded in the axils, with long, strict, roughish, capillary, \-flowered branches j 



