784 Obdeb 156.— GRAMINfLE. 



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 ; lvs. flat, 8 to 

 12' by 6" to 1', on 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. afi<fu t both or twain, Kapnos, 

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

 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 lvs., 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 1$-' 

 long, the radical ones 2A'', 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 panis, 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 $ , 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 numerous, racemed in large panicles. (*) 



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



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



a Panicle not capillary, <lense-flowered No. 8 



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



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



b Panicle open. — Glume 3-veined. The 2 pales equal No. 5 



— Glume 5 to 7-veined, — longer than abortive flower Nos. 6, 7 



— shorter than abortive flower No. 8 



* 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. 11 — IS 



** 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 flower white, (dd) 



dd Spikelets less than \" long, roundish or oval ; glume 5-veined.. .Nos. 15, 10 



dd Spikelets 1 to \\" long, oval ; glumo 9-veined Nos. 17, 18 



O Leaves broad, conspicuously veined, 5 to 20" wide, (e) 



e Abortive flower usually staminate with S stamens Nos. 18, 19 



e Abortive flower neutral, never with stamens, (f ) 



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



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



§ Spikelets barely acute, in short (1'), dense, secund, alternate spikes. Southern Nos. 23, 24 



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

 hairy, broad-linear, acuminate, 4 — 6' long; slieaths 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 rl. of 1 palea. — (D Fields and roadsides, TJ. 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. autumnale Bosc. Culm very slender, assurgent, 30 to 20f high; lvs. gla- 

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

 fuse, bearded in the axils, with long, strict, roughish, capillary, 1-flowered branches; 



