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VOLUME 17 PART 4

NORTH AMERICAN FLORA

(POALES)

POACEAE (pars)
ALBERT SPEAR HiTcHcock

PUBLISHED BY

THE NEW YORK BOTANICAL GARDEN

Aucust 14, 1931

Part 4, 1931] POACEAE 289

of the glumes, about twice as thick, strongly nerved; first glume nearly as long as the sterile
lemma, acuminate-pointed; second glume exceeding the sterile lemma, both much exceeding
the fruit and at maturity spreading and exposing it, acuminate-pointed, the summit of the
lemma arcuate, the sterile palea obsolete; fruit 2 mm. long, 1 mm. wide, obovate, stipitate,
smooth and shining.

TyYPrE LOCALITY: Savannah, Georgia.
DISTRIBUTION: Georgia to Florida and eastern Texas.
ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost. 17: f. 354; Contr. U. S. Nat. Herb. 15: f. 368.

EXCLUDED SPECIES
Brachiaria ciliatissima (Buckl.) Chase; Hitche. Bull. U. S. Dep. Agr.
Mie 22a LOZOE
Panicum ciliatissimum Buck]. Prel. Rep. Geol. & Agr. Surv. Tex. App. 4. 1866.

Plants perennial, producing long, leafy stolons, with short internodes, rooting at the
swollen nodes, the sheaths mostly longer than the internodes but usually not inclosing them,
the blades short, firm, and divaricately spreading; flowering stems usually sparingly branching,
erect or ascending, 15—40 cm. high, glabrous, the nodes bearded; leaf-sheaths sparsely, or some-
times rather densely, pilose, mostly shorter than the internodes; ligule densely hairy, less than
1 mm. long; blades 3—7 cm. long, 3-5 mm. wide, tapering from near the rounded base to a sharp
point, flat, puberulent or glabrous, usually ciliate along the lower portion of the thick, white
margin; panicles finally long-exserted, 3-6 cm. long, rarely more than 1 cm. wide, the few, erect
branches bearing approximate, short-pedicelled spikelets, placed with the back of the fruit
turned from the rachis, that is, the first glume toward the rachis; spikelets 4 mm. long, about
1.8 mm. wide, pointed; first glume three fourths the length of the spikelet or more, cuneate,
5-nerved, glabrous, or with a few silky hairs at the very base; second glume and sterile lemma
subequal, exceeding the fruit, 5-nerved, the internerves densely silky-pubescent, or in the
lemma sometimes nearly glabrous, the portion from the lateral nerves to the margins densely
clothed with white and glistening silky hairs, the sterile palea about two thirds as long as its
lemma; fruit 3 mm. long, about 1.6 mm. wide, ellipsoid, apiculate, transversely rugose.

TYPE LocaLity: Northern Texas.

DISTRIBUTION: Southwestern Arkansas and Texas.

ILLUSTRATION: Contr. U. S. Nat. Herb. 15: f. 363.

Nore 1: This supposed Panicum represents a third species of the genus Brachiaria, already
arty this work (see pages 160 and 161). It may readily be distinguished by its densely silky

Nore 2: Panicum disciferum Fourn. (Mex. Pl. Gram. 19. 1886) is also a Brachiaria, and
should be included among the synonyms of B. plantaginea (Link) Hitche. (page 160).

ADDITIONAL SPECIES (NOT IN THE KEY)

12a. Panicum didistichum Mez, Notizbl. Bot. Gart. Berlin 7:
63. 1917.
Differing from P. molle in the slightly smaller, more densely pubescent spikelets, more
closely set on the rachis.
Typr Locatity: Grenada, Nicaragua.

DISTRIBUTION: Known only from the type collection (Levy 1124).
87a. Panicum cyanescens Nees, Agrost. Bras. 220. 1829.

Differing from P. parvifolium in having less slender, more erect, firm culms, longer blades
(3-8 em. long), and stiffly ascending panicle-branches, naked below.

TYPE LOCALITY: Brazil.

DisTRiBuTION: British Honduras; Trinidad to Brazil.

DOUBTFUL SPECIES

Panicum ambitiosum Fourn. Mex. Pl. Gram. 30. 1886. ‘Type locality: Mexico. Probably a
species of Ichnanthus.

290 NORTH AMERICAN FLORA [VoLuME 17

Panicum densum Muhl. Descr. Gram. 122. 1817. Type locality: Eastern United States.

Panicum dichotomum spathaceum Wood, Bot. & Flor. ed. 1871. 393. 1871.

Panicum discolor Spreng. Mant. Fl. Hal. 31. 1807. Type locality: Pennsylvania.

Panicum flexuosum Raf. Jour. Bot. Desv. 4: 273. 1814. Type locality: New Jersey.

Panicum gracilescens Desv.; Poir. in Lam. Encye. Suppl. 4: 279. 1816. Type locality:
Carolina.

Panicum Rafinesquianum Schultes, in R. & S. Syst. Veg. Mant. 2: 257. 1824. Based on
P. flexuosum Raf.

Panicum sessilicaule Desv.; Hamilt. Proedr. 11. 1825. Type locality: Carolina?

Panicum speciosum Walt. Fl. Car. 73. 1788. Type locality: South Carolina.

Panicum vilfiforme Wood, Class-Book ed. 1861. 785. 1861. Type locality: Eastern Tennessee.

56. STEINCHISMA Raf.; Steud. Nom. Bot. ed. 2. 2:635. 1841.

See Panicum hians, page 236.

57. ICHNANTHUS Beauv. Agrost. 56. 1812.

Navicularia Bertol. Opusc. Sci. Bologna 3: 408. 1819. Not Navicularia Adans. 1763.

Perennial or rarely annual grasses with erect or creeping stems and flat usually
broad sometimes petioled leaf-blades. Inflorescence an open or contracted panicle, the
panicles terminal and axillary, the spikelets in pairs unequally short-pedicelled along the
stiffly spreading or ascending main branches. Spikelets with keeled glumes so as to appear
somewhat laterally compressed, similar in structure to those of Panicum, the glumes and
sterile lemma usually rather strongly nerved, and commonly ending in an apiculation or
convolute point. First glume usually more than half as long as the spikelet, 3-nerved, the
second glume and sterile lemma about equal, longer than the fruit, 5-nerved, the lemma
inclosing a membranaceous palea and rarely a staminate flower; fertile lemma usually acute or
acutish, indurate, dorsally compressed, usually raised on a short stipe, the margins usually
flat but in our species more or less inrolled, the base bearing on either side membranaceous
appendages adnate to the lemma below, free above, the appendages in most of our species
obsolete and indicated by minute scars or excavations only; palea entirely inclosed in the
margins of the lemma.

Abnormal specimens occur, especially in nos. 3-5, in which the sterile lemmas are greatly
multiplied, forming elongate curved spikelets as much as 2 em. long.

Type species, Ichnanthus panicoides Beauv.

Appendages of fertile lemma reduced to scars.
Leaf-blades petiolate, the petiole 1-15 mm. long; first glume acute, about half
as long as the spikelet.
Spikelets 3 mm. long; culms delicate, spreading, much-branched. 1. I. mayarensis.
Spikelets 3.5-4 mm. long; culms erect, simple or sparingly branched. 2. I. lanceolatus.
Leaf-blades sessile, clasping; first glume acuminate or attenuate-pointed,
mostly more than half as long as the spikelet.

Second glume hispid with slender hairs along the margin; culms delicate,
the leaf-blades mostly not more than 5 cm. long and 1 cm. wide; sterile
palea small and narrow. 3. I. tenuis.

Second glume glabrous or rarely with a very few hairs; plants com-

paratively stout, the leaf-blades mostly more than 1 cm. wide;
sterile palea well-developed, nearly as long as its lemma.
First glume about as long as the spikelet; fertile lemma nearly as long
as the spikelet; leaf-blades ovate-lanceolate to elliptic-lanceolate,
thin. 4. I. nemorosus.
First glume and fertile lemma shorter than the spikelet; leaf-blades
lanceolate to oval,

Leaf-blades lanceolate, 1-2 cm. wide, glabrous. 5. I. pallens.
Leaf-blades oval to ovate lanceolate, 1.5-3.5 cm. wide, often
pubescent beneath. 6. I. axillaris.
Appendages of fertile lemma evident.
Panicle of numerous clustered branches. 7. I. mexicanus.
Panicle of 2—5 racemes. 8. I. Standleyi.

Part 4, 1931] POACEAE 291

1. Ichnanthus mayarensis (Wright) Hitchce. Contr. U. S. Nat.
Herb. 12: 228. 1909.
Panicum mayarense Wright; Sauv. Anal. Acad. Ci. Habana 8: 206. 1871.
Ichnanthus Wrightit Hitchc. Contr. U.S. Nat. Herb. 12: 229. 1909.

Stems slender, wiry, straggling or spreading, rooting at the lower nodes, 20-40 cm. long,
smooth or the lower part minutely pubescent, striate, the nodes several; leaf-sheaths shorter,
often much shorter, than the internodes, striate, smooth or sparsely papillose-hispid on the
surface, puberulent on the margin, especially toward the apex; blades lanceolate to narrowly
elliptic, 2-5 cm. long, 3-6 mm. wide, striate, smooth throughout or scaberulous above, abruptly
narrowed at base into a petiole 1-5 mm. long, or on the sterile shoots as much as 15 mm. long;
panicles 2-8 cm. long, usually long-exserted, the few main branches as much as 3 cm. long,
rather stiffly spreading, the primary and secondary axes glabrous or scaberulous; spikelets
about 3 mm. long, lanceolate, nearly terete, acute, glabrous, the unequal pedicels 0.5-2 mm.
long; first glume 1.5 mm. long, broad and clasping at base, acute; second glume and sterile
lemma equal, 3 mm. long, acuminate, strongly nerved, the sterile palea narrow, about 1 mm.
long; fertile lemma 2 mm. long, acute, only slightly compressed dorsally, the margins inrolled,
nearly or quite meeting, the scars at base about 0.5 mm. long, the stipe obsolete.

TYPE LocALIty: Mayari Abajo, Cuba.

DISTRIBUTION: Eastern Cuba.
Intustration: Contr. U.S. Nat, Herb. 22: pl. J.

2. Ichnanthus lanceolatus Scribn. & Smith, Bull. U. S. Dep. Agr.
Agrost. 4:36. 1897.
Panicum Lindeni Fourn. Mex. Pl. Gram. 29. 1886. Not P. Lindenii Griseb. 1866.

Stems erect or slightly spreading at base, 40-60 cm. high, striate, glabrous or puberulent,
the nodes about 4, glabrous, or puberulent below the sheath-margin; leaf-sheaths shorter than
the internodes, striate, glabrous on the surface or the lowermost villous, the margin villous;
blades lanceolate to ovate-lanceolate, or the lower ovate, 5-7 cm. long, 1-3 cm. wide, the
uppermost reduced, rather firm in texture, glabrous or slightly scaberulous beneath, scabrous
above, narrowed from a rounded or cordate base into a petiole 1-10 mm. long; panicles terminal
and axillary, 5-12 cm. long, the one from the uppermost sheath smaller, the few branches
rather stiffly spreading, as much as 6 cm. long, the axes scaberulous; spikelets about 4 mm.
long, lanceolate, only slightly compressed laterally, glabrous, the pedicels scabrous, unequal,
the shorter of the pair about 1 mm. long, the longer about 3 mm. long; first glume 2 mm. long,
broad and clasping at base, acute; second glume and sterile lemma nearly equal, clasping at
base, acuminate, the sterile palea small and narrow, about 1 mm. long; fertile lemma nearly
3 mm. long, acute, the margins flat and overlapping toward the apex, inrolled and nearly
meeting toward the base, the scar at base very short, extending downward into a minute
wing on the very short stipe.

TyPeE LocaLity: Izamal, Yucatan.

DISTRIBUTION: Yucatan.

ILLustrations: Bull. U. S. Dep. Agr. Agrost. 4: pl. 5; Field Mus. Publ. Bot. 3: 36; Contr.
U.S. Nat. Herb. 22: pl. 6. ;

3. Ichnanthus tenuis (Presl) Hitchc. & Chase, Contr. U. S. Nat.
Herb. 18: 334. 1917.

Oplismenus tenuis Presi, Rel. Haenk. 1: 319. 1830.

Panicum exile Steud. Syn. Gram. 45. 1854.

Panicum alsinoides Griseb. Fl. Brit. W. Ind. 550. 1864.

Ichnanthus alsinoides Munro; Hemsl. Biol. Centr. Am. Bot. 3: 500. 1885.

Apparently annual; stems slender, spreading or creeping, rooting at the nodes, much-
branched, the fertile shoots ascending 10-20 cm. high, glabrous or puberulent, mostly in lines,
purplish; leaf-sheaths shorter than the internodes, papillose-hispid with weak slender hairs;
blades lanceolate, 2-5 cm. long, 4-10 mm. wide, sessile, rounded or slightly cordate at base,
acute or acuminate, thin, glabrous or puberulent, often sparsely hispid, the margins scabrous;
panicles terminal and axillary, 2-4 cm. long, or the axillary smaller, mostly on long slender

292 NORTH AMERICAN FLORA [VOLUME 17

peduncles, the few branches rather weakly spreading, as much as 2 cm. long, the axes slender,
angled, scaberulous and sometimes puberulent, often villous or with a few long hairs at the
base of the branches; spikelets narrowly lanceolate, 3 mm. long, acuminate, hispid, the pedicels
slender, unequal, the shorter of the pair 1 mm. or less, the other twice or thrice as long; first
glume broad and clasping at base, attenuate into a slender point nearly as long as the spikelet,
glabrous, scaberulous; second glume and sterile lemma nearly equal, acuminate, the former
attenuate-pointed, prominently nerved, hispid with slender hairs along the lateral nerves, the
sterile palea small and narrow; fertile lemma 1.5-2 mm. long, dorsally compressed, oblong,
rounded at the apex, the margins flat, widely separated, the scar about 0.3 mm. long, extending
downward into a wing decurrent on the short stipe of the lemma.
Type Locality: Panama.

DISTRIBUTION: Costa Rica to Panama and northern South America.
ItLustRations: Rep. Mo. Bot. Gard. 10: pl. 24; Contr. U. S. Nat. Herb. 22: pl. 2.

4. Ichnanthus nemorosus (Sw.) Ddll, in Mart. Fl. Bras. 27:
289. 1877.

Panicum nemorosum Sw. Prodr. 22. 1788.
Milium nemorosum Moench, Meth. Suppl. 67. 1802.
Echinolaena nemorosa Kunth, Rév. Gram. 1: 54. 1829.

Stems spreading and creeping, rooting at the nodes, much-branched, pubescent or
glabrescent, the nodes pubescent, the fertile shoots decumbent or rising 10-20 em.; leaf-
sheaths shorter than the internodes, pubescent or glabrescent, villous on the margin and collar;
blades ovate-lanceolate to elliptic-lanceolate, 3-7 cm. long, 1-2 cm. wide, clasping at the
usually unsymmetrical base, somewhat abruptly narrowed toward the apex, thin, sparsely
hispid and scaberulous on both surfaces, or glabrescent; panicles terminal and axillary, 1-4 cm.
long, ovate or often narrow, the few branches weakly spreading or appressed, usually not more
than 2 cm. long, the axes angled and scabrous, villous at the base of the branches; spikelets 2.5-3
mm. long, glabrous, the pedicels short, 1-2 mm. or less; first glume a little shorter than the
second and about as long as the sterile lemma, 5-nerved, the lateral nerves contiguous, broad
and somewhat clasping at the base, acuminate or attenuate-pointed at the apex, the keel scaber-
ulous above; second glume and sterile lemma 5-nerved, the lateral nerves distant, the glume
scaberulous on the keels, acuminate or attenuate-pointed, sometimes with a few hairs near the
margin, the lemma smooth on the keel, acute or somewhat rounded at apex; the sterile palea
well-developed, nearly as long as the lemma; fertile lemma lanceolate, 2 mm. long, acutish,
yellow-brown at maturity, the scar at base about 0.3 mm. long, bearing no wing below, the
margins somewhat inrolled, distant.

TYPE LOCALITY: Jamaica.

DISTRIBUTION: Southern Mexico to Panama; Cuba to Trinidad.
InLustRations: Trin. Ic. pl. 21/0; Contr. U. S. Nat. Herb. 22: fl. 3.

5. Ichnanthus pallens (Sw.) Munro; Benth. Fl. Hongk. 414. 1861.

Panicum pallens Sw. Prodr. 23. 1788.
Panicum hemignostum Steud. Syn. Gram. 77. 1854.
Panicum montanum Poit.; Fourn. Mex. Pl. Gram. 30, assynonym. 1886.

Stems much-branched, spreading, creeping at the base, rooting at the nodes, the fertile
culms ascending 30-80 cm. or sometimes more, puberulent; leaf-sheaths usually glabrous on
the surface, villous on the margin; blades lanceolate, often somewhat falcate, 5-10 cm. long,
mostly 1-2 cm. wide, somewhat clasping at the asymmetric narrowed base, somewhat abruptly
narrowed to an acuminate point, the lower surface glabrous or slightly seaberulous, roughened
with irregular cross-veins, sometimes with a few scattered stiff hairs, the upper surface
scaberulous, often with a few stiff hairs at the base and on the basal portion of the margin;
panicles terminal and from several of the upper axils, 5-10 cm. long, rather compact, elliptic,
the main branches ascending, as much as 6 cm. long, usually bearing secondary branches, the
axes angled and scabrous, pubescent at the base of the branches; spikelets 3-3.5 mm. long,
glabrous or rarely with a few stiff hairs; first glume 1.5—2 mm. long, somewhat clasping at base,
attenuate-pointed, scabrous on the keel; second glume longer than the sterile lemma, acuminate

Part 4, 1931] POACEAE 293

but scarcely attenuate-pointed, scabrous on the keel and roughened on the lateral nerves;
sterile lemma similar to the second glume but shorter and less narrowed at the summit, the
palea well-developed, nearly as long as the lemma; fertile lemma oblong, 1.5 mm. long, rounded
at apex, the margins inrolled, distant, the scars at base 0.3 mm. long, narrowly winged at the
side.

TYPE LOCALITY: Jamaica.
DISTRIBUTION: Eastern Mexico and the West Indies to tropical South America.
ILLustRaTions: Trin. Ic. pl. 211, 212A; Contr. U. S. Nat. Herb. 22: pl. 4.

6. Ichnanthus axillaris (Nees) Hitchce. & Chase, Contr. U. S. Nat.
Herb. 18: 334. 1917.

Panicum axillare Nees, Agrost. Bras. 141. 1829.

Stems much-branched, spreading or prostrate, rooting at the nodes, the fertile shoots
ascending 10-20 cm. in open ground, or among shrubs clambering to the height of 1—-1.5 meters,
puberulent or glabrescent; leaf-sheaths villous, at least on the margin; blades oval, ovate, or
ovate-lanceolate, 3-12 cm. long, 1.5—3.5 cm. wide, cordate-clasping at base, acute or acuminate,
rather thick and firm, pubescent or glabrous beneath, scabrous above; panicles terminal and
axillary, similar to those of J. pallens but averaging larger, sometimes as much as 20 cm. long;
spikelets similar to those of J. pallens in arrangement and structure, but usually larger; glumes
often sparsely pilose; sterile lemma containing a well-developed palea and a staminate flower;
fertile lemma 2 mm. long, with a prominent scar at base.

TYPE LOCALITY: Brazil. P
DISTRIBUTION: Hispaniola; Porto Rico; Guatemala to Panama and Brazil.

7. Ichnanthus mexicanus Fourn. Mex. Pl. Gram. 34. 1886.

Stems tall, glabrous; leaf-sheaths densely villous or glabrate; ligule a very short, densely
ciliate membrane; blades (only the upper seen) gradually narrowed from the cordate base to a
slender point, 8-18 cm. long, as much as 2.5 cm. wide near base, pubescent on both surfaces;
panicle 30 cm. long, about 8 cm. wide, rather densely flowered, the branches ascending,
clustered, the longer ones as much as 10 cm. long, spikelet-bearing from base; spikelets single
or in clusters along the scabrous rachis, 4-4.5 mm. long, the pedicels 1-2 mm. long, densely
scabrous-hispidulous; first glume about as long as the spikelet, 3-nerved, pointed, scabrous,
villous along the margins and at the apex; second glume about as long as the fruit, 5-nerved,
scabrous, the long hairs sparse or wanting; sterile lemma similar to the second glume but
weakly 5-nerved, the palea well developed, ciliate on the keels; fertile lemma about 3 mm.
long, the boat-shaped point distinct, the appendages rather firm, ovate-oblong, distinct from
near the base, about 0.5 mm. long.

TYPE LocALity: Trapiche de la Concepcion, Oaxaca.
DISTRIBUTION: Known only from the type locality.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 8.

8. Ichnanthus Standleyi Hitche. Contr. U. S. Nat. Herb. 24:
662. 1930.

Appare1 t y perennial; stems slender, spreading, branching, minutely pubescent; sheaths
rather sparingly pubescent, villous on the margin; ligule very short, densely ciliate; blades
ovate-lanceolate, somewhat acuminate-pointed, sparingly hispid on both surfaces, scabrous on
the margin, 4-6 cm. long, 1-2 cm. wide, often petioled, the petiole slender, as much as 15 mm.
long; inflorescence long-exserted, consisting of 2—5 racemes 1-2 cm. apart and 5-10 mm.
long, finally more or less reflexed; spikelets dark-purple, about 5 mm. long; glumes about as
long as the spikelet, acuminate, sparsely hispidulous, pilose on the margins; sterile lemma
similar to the glumes but less acuminate; fertile lemma white, elliptic, about 3.5 mm. long, the
wings or appendages evident but minute, about 0.5 mm. long.

TYPE LOCALITY: Siguatepeque, Honduras.
DistriBution: Known only from the type locality.

294 NORTH AMERICAN FLORA [VoLUME 17

DOUBTFUL SPECIES

Panicum Schlechtendalii Fourn. Mex. Pl. Gram. 22, 30. 1886. Probably Ichnanthus nemorosus.
Panicum Schlechtendalii monstrosum Fourn. Mex. Pl. Gram. 31. 1886. Based upon a specimen
(Mirador, Galeotti 5689) with abnormal spikelets; probably Ichnanthus pallens.

58. LASIACIS (Griseb.) Hitche.; Hitche. & Chase, Contr. U.S.
Nat. Herb. 15: 16. 1910.
Panicum § Lasiacis Griseb. Fl. Brit. W. Ind. 551. 1864.

Perennial shrubby often climbing grasses with much-branched stems (herbaceous and
simple in L. procerrima), flat often slightly petiolate leaf-blades, and open or somewhat con-
tracted panicles terminating the main stem and primary branches, reduced panicles terminating
the secondary often fascicled branches. Spikelets subglobose, ovoid or ellipsoid, placed
obliquely on their pedicels, the glumes and sterile lemma broad, abruptly apiculate, papery-
chartaceous, shining, often black at maturity, many-nerved, glabrous, or lanose at the apex
only. First glume rarely more than one third the length of the spikelet, somewhat inflated-ven-
tricose. Second glume and sterile lemma subequal, about as long as the fertile lemma, or the
glume slightly shorter, the lemma inclosing a membranaceous palea and sometimes a staminate
flower. Fertile lemma white, bony-indurate, obovoid, obtuse, the margins inrolled inclosing
the edges of the indurate palea, both lemma and palea bearing at the apex in a slight crateriform
excavation a tuft of woolly hairs, the palea concave below, gibbous above, the apex often free
at maturity.

Type species, Panicum divaricatum L.

Stems erect, simple, annual; leaf-blades as much as 40 cm. long and 5 cm. wide,
deeply cordate-clasping. 1. L. procerrima.
Stems much-branched, woody; leaf-blades mostly less than 20 cm. long,
narrowed at base or somewhat cordate.
Main stem prostrate, the fertile shoots prostrate, ascending or erect.
Leaf-blades lanceolate, mostiy less than 5 cm. long; fertile shoots
strongly dorsiventral, mostly prostrate.
Leaf-blades linear-lanceolate, about 10-12 cm. long; fertile shoots
ascending or erect from a decumbent base, not dorsiventral. 3. L. Grisebachii.
Main stem clambering, or much branched and forming a tangled mass.
ligule noticeable, brownish, about 2 mm. long.
Spikelets clustered toward the tips of the slender scabrous branches;
blades elongate, more than 10 times as long as wide, scabrous on
the upper surface. 4. L. oaxacensis.
Spikelets not clustered toward the tips of the branches (somewhat so
in L. Standleyi); blades less than 10 times as long as wide.
Blades glabrous on the upper surface. 5. L. ligulata.
Blades scabrous on the upper surface.
Panicles ovoid, 5-6 cm. long, the branches short, spreading

L. Rugelii.

to

or reflexed. 6. L. scabrior.
Panicles 10-15 cm. long, the branches ascending, naked
below. 7. L. Standleyi.

Ligule inconspicuous, hidden within the mouth of the sheath, rarely as
much as | mm. long.
Stems not high-climbing, decumbent and rooting at base, forming a
tangled mass, with no strong central cane; spikelets clustered
toward the ends of the branches. 8. 1. rhizophora.
Stems high-climbing, forming a strong central cane; spikelets not
clustered toward the ends of the branches.
Teaf-blades glabrous on both surfaces, often more or less scabrous.
(See L. ruscifolia, rarely with glabrous ovate-lanceolate
blades.) NM
Main stem papillose-hispid; lateral flowering branches gla-
brous; panicles smal] and narrow. 9. L. leptostachya.
Main stem (except sometimes the young shoots) smooth.
Leaf-blades narrow, usually 3-4 mm., sometimes 5 mm.
wide, 8-10 cm. long. 10. L. Harrisii.
Tent Dlades more than 5 mm. wide if as much as 10 cm.
ong.
Panicles few-flowered, 5-10 cm. long; branches strongly
zigzag, the branchlets strongly divaricate or reflexed;
blades narrowly lanceolate, firm, mostly less than
1 cm. wide (sometimes wider on vigorous shoots). ll. L. divaricata.
Panicles many-flowered, usually 15-25 cm. or more

Part 4, 1931] POACEAE 295

long on the primary branches; branches straight
or arcuate, not zigzag; blades mostly more than

1.5 cm. wide.

Spikelets globose, about 3 mm. long. 12. L. globosa.
Spikelets lanceolate-ellipsoid, 3.5—5 mm. long.

Spikelets 4.5-5 mm. long, on short stiff ap-
pressed pedicels; blades oblong-ovate or
elliptic-lanceolate. 13.

Spikelets 3.5—4 mm. long, on flexuous spreading
pedicels; blades lanceolate or narrowly-lanceo-
late. 14. L. patentiflora.

Leaf-blades pubescent on one or both surfaces (sometimes
glabrous in L. ruscifolia).
Blades narrowly lanceolate, averaging 8-10 times as long as
wide; panicle large and open; spikelets 4-5 mm. long. 15. L. sorghoidea.
Blades ovate-lanceolate or elliptic, sometimes lanceolate, often
more or less cordate-clasping; panicle often compact or
at least the branches commonly compactly flowered;
spikelets 3-4 mm. long.
Sterile lemma 1. 16. L. ruscifolia.
Sterile lemmas 2. 17. L. anomala.

. Sloanei.

ty

1. Lasiacis procerrima (Hack.) Hitche.; Chase, Proc. Biol. Soc.
Wash. 24: 145. 1911.
Panicum procerrimum Hack. Oesterr. Bot. Zeits. 51: 431. 1901.

Stems succulent, somewhat woody at base but not perennial, erect from a thick woody
rootstock, simple, as much as 4 meters high and 1 cm. thick, glabrous, glaucous; leaf-sheaths
usually overlapping, glabrous or rarely pubescent; ligule inconspicuous; blades narrowly
lanceolate, 15-40 cm. long, 2-5 cm. wide, deeply cordate-clasping, the lobes overlapping,
gradually acuminate at apex, glabrous and glaucous, rarely pubescent, the basal lobes some-
times ciliate; panicles very large, open and much-branched, as much as | meter long, the
branches naked below, finally widely spreading, the lower in whorls, as much as 40 cm. long,
the main axis smooth, the branchlets and pedicels scabrous; spikelets scattered, 3-4 mm.
long, ovoid or elliptic.

Type Loca.ity: On the river Tiliri near La Verbena and Alajuelita, Costa Rica.

DISTRIBUTION: Central Mexico to Panama and northern South America.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 10.

2. Lasiacis Rugelii (Griseb.) Hitche. Bot. Gaz. 51: 302. 1911.

Panicum Rugelii Griseb. Cat. Pl. Cub. 233. 1866.

Stems much-branched, prostrate, the main ones slender, mostly about 2 mm., sometimes
2.5 mm. thick, appressed-hispidulous, the sterile shoots prostrate, the leaves strongly distichous
and dorsiventral, approximate, the fertile shoots sometimes ascending toward the end; leaf-
sheaths overlapping, hispidulous, villous on the margin and around the summit; ligule incon-
spicuous; blades lanceolate or oblong-lanceolate, 2-5 cm. long, 4-12 mm. wide, hispidulous or
puberulent on both surfaces; panicles small and few-flowered, usually not more than 5 cm.
long, the few branches spreading, the axes pubescent, scabrous on the angles; spikelets 5
mm. long.

Type LocaLity: Matanzas, Cuba.
DIstRIBUTION: Western Cuba; Haiti; Yucatan; San Luis Potosi.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 11.

3. Lasiacis Grisebachii (Nash) Hitche. Bot. Gaz. 51: 302. 1911.
Panicum Grisebachii Nash, Bull. Torrey Club 35: 301. 1908.

Stems much-branched, glabrous, the main ones creeping and rooting at the nodes, as
much as 2 mm. in diameter, the fertile shoots erect or ascending, 20-40 cm. high; leaf-sheaths
hispidulous especially on the margin, or the surface glabrescent; ligule inconspicuous; blades
narrowly lanceolate, 6-12 cm. long, 5-10 mm. wide, puberulent beneath, glabrous above,
scabrous on the margin; panicles ovate, mostly 5-6 cm. sometimes 10 cm. long, the few branches
rather stiffly ascending, few-flowered; spikelets 4 mm. long, similar to those of L. divaricata.

Tyre Locality: Madruga, Cuba.

Distrripution: Western Cuba; Vera Cruz to Honduras,
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 12.

296 NORTH AMERICAN FLORA [VOLUME 17

4. Lasiacis oaxacensis (Steud.) Hitche.; Chase, Proc. Biol. Soc.
Wash. 24: 145. 1911.

Panicum oaxacense Steud. Syn. Gram. 73. 1854.

Plants straggling and branching but not high-climbing nor with a strong central cane;
stems decumbent and geniculate at base, rooting at the lower nodes, the ascending branches
1-2 meters long, glabrous; leaf-sheaths glabrous or rarely appressed-pubescent, the margin
villous; ligule prominent, 2-5 mm. long, brownish; blades narrowly lanceolate, 10-25 cm. long,
1-2 em. wide, abruptly narrowed at base, long-tapering at apex, scabrous on both surfaces;
panicles open, as much as 30 cm. long and nearly as wide, the slender scabrous branches and
branchlets ascending below, drooping above, naked below, the spikelets clustered toward the
tips, no smaller secondary panicles present; spikelets 4 mm. long, elliptic, often purple.

TYPE LOCALITY: Oaxaca.

DISTRIBUTION: Western Jamaica; Hispaniola; southern Mexico to Panama and Ecuador.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: pl. 13.

5. Lasiacis ligulata Hitche. & Chase, Contr. U. S. Nat. Herb. 18:
337. 1917.
Panicum divaricatum puberulum Griseb. Fl. Brit. W. Ind. 551. 1864.

Clambering to a height of 5-10 meters, the robust glabrous central cane as much as | cm.
in diameter, the wide-spreading main branches and the arcuate secondary ones not in fascicles,
not zigzag; sheaths ciliate on the overlapping margin, otherwise glabrous; ligule membra-
naceous-ciliate, brown, 1—2 mm. long; blades flat, firm, 6-12 cm. long, 0.8—1.5 cm. wide, lanceo-
late, acuminate, narrowed to the base, glabrous on the upper surface, puberulent or glabrous
beneath, the margins scabrous; panicles terminating the numerous branches, exserted or
partly included, oval in outline, rather open, 5-10 cm. long, usually half to three fourths as
wide, the branches few, spreading, finally reflexed, branching or flowering from near the base,
usually bearing 5-10 short-pedicelled spikelets; spikelets about 4 mm. long, obovoid and
purplish-black at maturity, the glumes and sterile lemma as well as the fruit with a lanate
tuft at the tip.

TYPE LOCALITY: Port of Spain, Trinidad.
DISTRIBUTION: Porto Rico to Ecuador and Brazil.
ILLUSTRATIONS: Kunth, Rév. Gram. pl. 29; Contr. U.S. Nat. Herb. 22: pl. 14.

6. Lasiacis scabrior Hitche. Proc. Biol. Soc. Wash. 40: 85. 1927.

Stems climbing or straggling, woody, as much as 3 meters tall, pubescent or glabrescent;
leaf-sheaths more or less hispidulous, densely villous on the margin; ligule prominent, brown,
mostly 3-5 mm. long; blades rather firm, elliptic-lanceolate, mostly 8-12 cm. long and 11.5
em. wide, harshly scabrous on the upper surface, puberulent beneath; panicles not much
exserted, ovoid, rather densely flowered, mostly 5-6 cm. long, sometimes as much as 10 em.,
the branches spreading, or the lower finally reflexed, the axis and branches pubescent; spikelets
ovoid, pale, about 4 mm. long.

TYPE LocaLity: Cubilquitz, Guatemala.
DISTRIBUTION: Nicaragua to Panama.

7. Lasiacis Standleyi Hitche. Proc. Biol. Soc. Wash. 40: 86. 1927.

Stems branching and straggling, mostly 1-2 meters tall, rooting at the nodes with slender
branching stilt-roots; leaf-sheaths glabrous or hispidulous; ligule prominent, brown, 3-5 mm.
or even 8 mm. long; blades narrowly elliptic-lanceolate, 10-15 cm. long, 1—2.5 em. or rarely
3 cm. wide, somewhat falcate, scabrous on the upper surface, minutely pubescent beneath;
panicles 10-15 cm. long, the few branches stiffly ascending, the spikelets somewhat clustered
toward the ends of the scabrous branches and branchlets; spikelets ovoid-globular, pale or
finally dark, about 4 mm. long.

TYPE LocaLity: La Tejona, Costa Rica.
DISTRIBUTION: Costa Rica.

Part 4, 1931] POACEAE 297

8. Lasiacis rhizophora (Fourn.) Hitche.; Chase, Proc. Biol. Soc.
Wash. 24: 145. 1911.

Panicum rhizophorum Fourn. Mex. Pl. Gram. 31. 1886.

Stems branching and straggling, not forming a strong central cane, decumbent at base
and rooting at the lower nodes, the fertile stems ascending, 30-100 cm. long, glabrous or
pubescent; leaf-sheaths appressed-hispidulous or glabrescent, villous on the margin; ligule
inconspicuous; blades lanceolate to ovate-lanceolate, 7-14 cm. long, 1.5—-3 em. wide, somewhat
cordate at base, rather abruptly narrowed above to an acuminate point, pubescent or scabrous
beneath, scabrous above; panicles 8-15 cm. long, the branches stiffly ascending, naked below,
the spikelets clustered toward their tips, the axis scabrous; spikelets 3-4 mm. long, ovoid.

TYPE LOCALITY: Orizaba, Mexico.

DISTRIBUTION: Southern Mexico to Costa Rica.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 15.

9. Lasiacis leptostachya Hitche. Contr. U. S. Nat. Herb. 22:
LOS 31920)

Plants forming a stout central cane, with numerous slender branches at the nodes,
clambering to the height of several meters; main stems roughened and somewhat cinereous
with papillae and irregularly appressed hairs; floral branchlets slender, conspicuously zigzag,
smooth, 20—40 cm. long; leaf-sheaths glabrous or nearly so, densely long-ciliate on the margin,
hirsute on the collar; ligule inconspicuous, about 0.5 mm. long; blades narrowly lanceolate,
7-10 em. long, 5—10 mm. wide, narrowed toward each end, glabrous on both surfaces; panicles
small and narrow, rather dense, 2—4 cm. long, few-flowered; spikelets about 5 mm. long, oblong-
ovoid, pale; first glume about one third as long as the spikelet; second glume and sterile lemma
equal, as long as the spikelet, woolly at tip; fertile lemma as long as the sterile, woolly at the tip.

TYPE LOCALITY: Jinotepe, Nicaragua.

DISTRIBUTION: Known only from the type locality.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: pl. 16.

10. Lasiacis Harrisii Nash, Torreya 13: 274. 1913.

Stems clambering among bushes to the height of 5 meters or more, the main canes slender
but strong, the very slender branches pendent, the young twigs commonly rosy-purple; leaf-
sheaths slender, glabrous except the margin and throat, or rarely the young ones sparsely hispid;
ligule inconspicuous; blades linear-lanceolate, 5—10 cm. long, 2-6 mm. wide, gradually narrowed
to an acuminate apex, thin and lax, glabrous, the margins scabrous; panicles narrow, mostly
less than 5 cm. long, often partially included in the uppermost sheath, the branches short and
appressed, the longer usually not more than | cm. long, and bearing not more than 4 spikelets;
spikelets similar to those of L. divaricata but less turgid.

TYPE LocaLity: Cinchona, Jamaica.
Distrisution: At 1000-1500 meters, Jamaica and Porto Rico.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: pl. 17.

11. Lasiacis divaricata (L.) Hitche.; Hitche. & Chase, Contr. U. S. Nat.
Herb. 15: 16. 1910.

Panicum divaricatum 1. Syst. Nat. ed. 19.871. 1759.

Panicum bambusoides Desy.; Hamilt. Prodr. 10. 1825.

Panicum Chauvinii Steud. Syn. Gram. 68. 1854.

Panicum divaricatum stenostachyum Griseb. Fl. Brit. W. Ind. 551. 1864.

Plants usually glabrous throughout except the margin of the sheaths; stems woody, much-
branched, clambering over shrubs to the height of 3-4 meters, the main cane strong, as much
as 6 mm. in diameter, the main branches often fascicled, the vigorous secondary sterile shoots
usually strongly divaricate or zigzag, the prophyllum prominent at the base of the branches;
leaf-sheaths glabrous except the villous or ciliate margin and the sometimes hispid collar;
ligule very short, not noticeable without displacing the blade; blades narrowly lanceolate,
5-12 em. long, 5—15 mm. wide, or on the vigorous sterile shoots much larger, narrowed at the

298 NORTH AMERICAN FLORA [VOLUME 17

base, gradually narrowed above to an acuminate point, scabrous on the margin and sometimes
slightly on the surface, the older deciduous from the sheaths, the basal portion of the fertile
shoots bearing the old sheaths but otherwise naked; panicles terminating the main culm and
the fertile branches, ovate or oblong, 5-20 cm. long, loosely flowered, the branches distant,
spreading or often reflexed, the axes angled, scabrous, flexuous, the lower usually 2-4 cm.,
sometimes as much as 10 cm. long, the main branches ordinarily 5-10-flowered; spikelets ovoid,
about 4 mm. long.

TYPE LOCALITY: Jamaica. : 4 \ :
DISTRIBUTION: At low altitudes, southern Florida; West Indies; Mexico to Panama and tropical

South America.
ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost. 17: f. 353; Vasey, Agr. Grasses U. S. pl. 13;
Proc. Biol. Soc. Wash. 24: 145. f. 11; Field Mus. Publ. Bot. 3: 33; Contr. U.S. Nat. Herb. 22: pl. 18.

12. Lasiacis globosa Hitche. Contr. U. S. Nat. Herb. 17:
Dole, LOTS:

Stems climbing, glabrous; leaf-sheaths glabrous, ciliate on the overlapping margin; ligule
a narrow pilose membrane about 0.5 mm. long; blades firm, elliptic-lanceolate, scabrous on the
margins and upper surface and more or less so beneath, those of the flowering branches 8 to 12
cm. long, 1 to 2 cm. wide; panicle pyramidal, loosely flowered, 6 to 15 cm. long, the branches
very scabrous, widely spreading, the longer as much as 7 cm. long; spikelets on scabrous pedicels
1 to 2cm. long, globose, 3 mm. long; first glume circular, gibbous, nerved, scabrous on the keel,
ciliate on the membranaceous margin, about 1 mm. long; second glume and sterile lemma
glabrous and shining, equal, a little shorter than the fertile lemma, reticulate-veined, lanate-
ciliate on the rounded apex; fertile lemma umbonate, the point protruding from the second
glume and sterile lemma, this and the apex of the palea woolly.

TYPE LOCALITY: Acapulco, Mexico.

DISTRIBUTION: Western Mexico.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 19.

13. Lasiacis Sloanei (Griseb.) Hitche. Bot. Gaz. 51: 302. 1911.
Panicum latifolium Hamilt. Prodr. 10. 1825. Not P. latifolium 1, 1753.
Panicum Sloanei Griseb. Fl. Brit. W. Ind. 551. 1864.

Climbing to the height of 3 or 4 meters, forming a strong central cane, the stems glabrous,
the branches solitary or 2 or 3 together, elongate; leaf-sheaths glabrous except the margin,
the collar conspicuously villous; ligule inconspicuous; blades oblong-ovate or elliptic-lanceolate,
10-15 em. long, 2.5—4 em. wide, those of the branches smaller, narrowed at the unsymmetrical
base, abruptly narrowed above to an acuminate point, somewhat papery in texture when dry,
glabrous on both surfaces or scabrous above, scabrous on the margin; panicles open and usually
loosely few-flowered, 10—20 cm. long, the branches distant and widely spreading, the lower as
much as 10 em. long, flexuous, scaberulous; spikelets 4-5 mm. long, elliptic.

TYPE LOCALITY: Jamaica.
DISTRIBUTION: West Indies to northern South America; central Mexico to Costa Rica.
ILLUSTRATIONS: Sloane, Hist. Jam. pl. 71, f. 3; Contr. U. S. Nat. Herb. 22: pl. 20.

14. Lasiacis patentiflora Hitchc. & Chase, Contr. U. S. Nat.
Herb. 18: 338. 1917.

High-climbing with a strong central cane as much as 8 mm. thick, the plant glabrous
throughout except at the summit of the sheaths; branches numerous, solitary, widely spreading
and finally repeatedly branching, the branches and branchlets straight or arcuate, divergent at
a rather narrow angle; sheaths with a ring of hairs at the summit or at least a tuft of hairs on
either side, sometimes pubescent on the margins toward the summit; ligule about 0.5 mm.
long, thin-membranaceous; blades on vigorous shoots as much as 14 cm. long and 2.5 mm.
wide, but mostly about 8-12 cm. long and 1.5-2 cm. wide, acuminate, rounded-tapering to
the base, usually somewhat asymmetric, glabrous, scabrous on the margin and somewhat so
on both surfaces; panicles numerous, short-exserted, mostly 12-20 cm. long, nearly as wide,
the slender axis and distant spreading flexuous branchlets angled, scabrous, the pedicels

Part 4, 1931] POACEAE 299

flexuous, spreading; spikelets pale, blotched with dark blue or purple at maturity, 3.4-3.8 mm.
long, globose-obovoid, the glumes and sterile lemma lanate-ciliate on the margin toward the
apex; fruit 3 mm. long, 2 mm. wide.

TYPE LocALIty: Tobago.
DistRIBuTION: Dominica; Salvador to Venezuela, Trinidad, and British Guiana.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: pl. 21.

15. Lasiacis sorghoidea (Desv.) Hitche. & Chase, Contr. U. S.
Nat. Herb. 18: 338. 1917.

Panicum lanatum Sw. Prodr. 24. 1788. Not P. lanatum Rottb. 1776.
Panicum sorghoideum Desv.; Hamilt. Prodr. 10. 1825.

Panicum orinocense Willd.; Spreng. Syst. 1: 316, assynonym. 1825,
Panicum praegnans Steud. Syn. Gram. 74. 1854.

Panicum lanatum sorghoideum Griseb. Fl. Brit. W. Ind. 551. 1864.
Panicum martinicense Griseb. Fl. Brit. W. Ind. 552. 1864.

Panicum Swartzianum Hitche. Contr. U.S. Nat. Herb. 12: 140. 1908.
Lasiacis Swartzianum Hitchc. Bot. Gaz. 51: 302. 1911.

Stems much-branched, erect or clambering to a height of 5—7 meters, the strong central
cane as much as | cm. thick, glabrous, or pubescent, the main branches sometimes 1 meter or
more long, arcuate, bearing slender branchlets toward the pendent ends or the branchlets
fascicled on the main stem, thé young shoots usually pubescent; leaf-sheaths pubescent
especially on the margin and collar, the surface sometimes glabrate; ligule inconspicuous;
blades lanceolate or elliptic-lanceolate, those of the main stem or of vigorous shoots as much
as 20 cm. long and 3 cm. wide, those of the fertile branches usually 8-12 cm. long and 1.5 em.
wide, or on the fascicled branchlets smaller, often falcate, velvety on both surfaces or puberulent
only, or glabrate above; panicles on the main stem and larger branches usually 10-20 cm. long,
at maturity as wide or wider, many and rather compactly flowered, the branches long and
again branched, the axes very scabrous; spikelets 4-5 mm. long.

TYPE LOCALITY: Porto Rico.
DisTRIBuTION: Throughout the West Indies but rare in Cuba; Mexico to tropical South

America.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 22

16. Lasiacis ruscifolia (H.B.K.) Hitche.; Chase, Proc. Biol. Soc. Wash.
24: 145. 1911.

Panicum ruscifolium H.B.K. Nov. Gen. & Sp.1: 101. 1815.

Panicum compactum Sw. Adnot. Bot. 14. 1829. Not P. compactum Kit.; Schultes, Oesterr. Fl.
ed. 2.1:212, assynonym. 1814.

Panicum megacarpum Steud.; Griseb. Fl. Brit. W. Ind. 551, assynonym. 1864.

Panicum Liebmannianum Fourn. Mex. Pl. Gram. 33. 1886.

Lasiacis compacta Hitche. Bot. Gaz. 51: 302. 1911.

Lasiacis Liebmanniana Hitche.; Chase, Proc. Biol. Soc. Wash. 24: 145. 1911.

More robust than any other species, freely branching, the shoots usually strongly dorsi-
ventral; stems becoming several meters long, glabrous or rarely puberulent; leaf-sheaths often
overlapping, glabrous on the surface or sometimes hispidulous toward the apex (in some Central
American specimens papillose-hispid throughout), glabrous or often ciliate or villous on the
margin especially near the summit, the collar glabrous or villous; ligule inconspicuous; blades
ovate-lanceolate or elliptic, sometimes lanceolate, the primary 10-15 cm. long, 3-6 cm. wide,
narrowed or often cordate-clasping at the asymmetric base, rather abruptly narrowed to an
acuminate but not attenuate apex, puberulent or glabrous beneath, glabrous or scabrous above,
the secondary blades similar or reduced; panicles narrow and compact, 5-20 cm. long, or often
with distant lower branches, these compactly flowered, or rarely the panicle somewhat open,
with spreading implicate but rather closely flowered branches, the axes hispidulous and
scabrous; spikelets 3-4 mm. long, nearly globose at maturity.

Type Locauity: Volcan de Jorullo, Mexico.
DiIstRIBuTION: Mostly near the coast, Cuba ae far Mexico to northern South America.

ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 2.

17. Lasiacis anomala Hitche. Jour. Wash. Acad. Sci. 9: 37. 1919.

Stems woody, branching, clambering over bushes, glabrous, the main stem as much as
5.5 mm. thick and 5 meters long; leaf-sheaths glabrous or more or less pilose, striate, ciliate,

300 NORTH AMERICAN FLORA [VoLuME 17

densely villous on the collar; ligule a short ciliate membrane; blades ovate-lanceolate or elliptic-
lanceolate, as much as 10 cm. long and 3 cm. wide on the main flowering stems, usually 4-6 cm.
long and 1—2 cm. wide on the lateral flowering branches, rather thin, narrowed and usually
asymmetric at base, sometimes a little cordate-clasping, puberulent, or sometimes glabrate on
the upper surface; panicles oblong-ovoid, 7-10 cm. long, 3-5 cm. wide, those on the lateral
branches smaller, the lower branches somewhat distant, spreading or somewhat reflexed, all
rather compactly flowered, puberulent, the pedicels angled, rather stout, 1-2 mm. long;
spikelets ovoid, becoming nearly globose at maturity, 3-4 mm. long; first glume about one
third, second glume about two thirds, as long as the spikelet; first and second sterile lemmas
about equal and about as long as the fertile lemma, the glumes and lemmas slightly woolly
at the tip, the second sterile lemma infolding the fruit more closely than usual for the first
lemma in other species; fruit ovoid-globose, obtuse, because of the presence of a second sterile
lemma, the palea side facing the second glume.
TYPE LOCALITY: Trinidad.

DISTRIBUTION: Trinidad to eastern Brazil.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 24.

DOUBTFUL SPECIES

Panicum maculatum Aubl. Pl. Guian. 51. 1775. This cannot be identified from the brief
description. The species described under this name by Schultes (in R. & S. Syst. Veg.
Mant. 2: 238. 1824) appears to be Lasiacis ligulata. Urban * states that the name is
based on “ Milium arundinaceum scandens et maculatum Plum. Msc. IV. tab. 82” which
Aublet cites, and that Plumier’s plant came from Martinique. He also states that the
plate cited represents either Lasiacis sorghoidea or L. Sloanei. Since the former species
is common in Martinique and the latter has not been found there, he assumes that the
name P. maculatum applies to what has been called Lastacis sorghoidea.

Panicum glutinosum am. Tab. Encye.1:174. 1791. Not P. glutinosum Sw. 1788. Probably
Lastacis sorghoidea.

Panicum agglutinans Kunth, Enum. Pl.1: 120. 1833. Based upon Panicum glutinosum Lam.

59. SACCIOLEPIS Nash, in Britton, Man. 89. 1901.

Annual or perennial subaquatic grasses with narrow leaf-blades and spike-like panicles.
Spikelets oblong or ovate-oblong, prominently nerved. First glume not more than half as long
as the spikelet. Second glume and sterile lemma about equal, the former distinctly and the
latter slightly gibbous at base, several-nerved, inflated and longer than the indurate slightly
stipitate fertile lemma.

Type species, Panicum gibbum Ell.

Spikelets 4 mm. long; culms decumbent and rooting at base; at least the lower leaf-

sheaths hispid. 1. S. striata.
Spikelets 2-3 mm. long; culms erect, leaf-sheaths glabrous.
Plants perenniai; spikelets 3 mm. long. 2. S. vilvoides.
Plants annual; spikelets 2 mm. long. 3. S. myuros.

1. Sacciolepis striata (L.) Nash, Bull. Torrey Club 30: 383. 1903.

Holcus striatus ,. Sp. Pl. 1048. 1753.

Panicum striatum Lam. Tab. Encye. 1: 172. 1791.

Panicum gibbum Ell. Bot. S. C. & Ga. 1: 116. 1816.

Panicum aquaticum Muhl. Descr. Gram. 126. 1817.

Panicum hydrophilum Schultes, in R. & S. Syst. Veg. Mant. 2: 237. 1824.
Panicum Elliottianum Schultes, in R. & S. Syst. Veg. Mant. 2: 256. 1824.
Panicum aquaticum Bosc.; Spreng. Syst. 1:319. 1825.

Panicum bermudianum Steud. Syn. Gram. 99. 1854.

Hymenachne striata Griseb. Fl. Brit. W. Ind. 354. 1861.

Sacciolepis gibba Nash, in Britton, Man. 89. 1901.

Perennial; stems rooting at the decumbent or creeping base, 50-150 cm. high, glabrous,
the nodes often villous; leaf-sheaths hispid or the upper glabrous; ligule inconspicuous, a

* Repert. Sp. Nov. 16: 149. 1919.

Part 4, 1931] POACEAE 301

ciliate fringe; blades linear-lanceolate, 10-20 cm. long, 4-10 mm. wide, abruptly rounded or
cordate, gradually narrowed from below the middle to an acuminate apex, appressed-hispidulous
on both surfaces, or glabrous, the margin scabrous, ciliate near the base; panicle narrow, almost
spike-like, 5-20 cm. long, the branches appressed, the lower sometimes as much as 5 em. long,
the axis and pedicels glabrous, the latter slender, flexuous, 1-3 mm. long; spikelets about 4 mm.
long, 1 mm. thick, oblong, prominently nerved, yellowish-green, glabrous; first glume ovate,
1 mm. long, 3-nerved; second glume broad, saccate or gibbous at base, a little shorter than
the sterile lemma, abruptly acute, about 11-nerved; sterile lemma flat, somewhat concave on
the back, abruptly acute, the few lateral nerves near the margin, the palea thin, nearly as
long as its lemma; fertile lemma oblong, 1.5 mm. long, inrolled at the margins, the rounded
summit of the palea free.

TYPE LOCALITY: Virginia.

DISTRIBUTION: New Jersey to Florida, and westward to Oklahoma and eastern Texas; Cuba,
Porto Rico, and Jamaica.

ILLUSTRATIONS: Proc. Biol. Soc. Wash. 21:6. f. 2; Vasey, Agr. Grasses U.S. pl. 14; ed. 2. pl. 103;
Britt. & Brown, Ill. Fl. f. 279; ed. 2. f. 387.

2. Sacciolepis vilvoides (Trin.) Chase, Proc. Biol. Soc. Wash.
ZN el SOSe
Panicum vilvoides Trin. Gram. Pan. 171. 1826.
Hymenachne fluviatilis Nees, Agrost. Bras. 273. 1829.

Plants perennial, erect, glabrous throughout; stems 80-150 cm. high, succulent; leaf-
sheaths striate, mostly longer than the nodes; ligule a thin membrane about 1 mm. long;
blades linear, the lower 5—10 cm. long, the middle 20-30 cm. long, the uppermost 5-10 cm.
long, all 2-6 mm. wide; panicle close and spike-like, 10-40 cm. long, about 5 cm. thick, the
pedicels mostly less than 1 cm. long; spikelets 3 mm. long, narrowed upward, prominently
nerved, glabrous; first glume oblong-ovate, 1.5 mm. long; second glume and sterile lemma
about equal, somewhat gibbous at base, 7-nerved, the sterile palea narrow, about half as long
as the lemma; fertile lemma nearly 2 mm. long, little depressed, the margins flat.

Type LocaLity: Brazil.
DISTRIBUTION: Cuba; tropical South America.
ILLUSTRATION: Trin. Ic. pl. 204

3. Sacciolepis myuros (Iam.) Chase, Proc. Biol. Soc. Wash.
ZAEwien 908"

Panicum myuros Lam. Tab. Encye.1:172. 1791.

Panicum myosurus Rich. Act. Soc. Hist. Nat. Paris 1: 106. 1792.
Hymenachne myurus Beauv. Agrost. 49, 165. 1812.

Panicum phleiforme Presi, Rel. Haenk. 1: 302. 1830.

Plants annual, glabrous except the upper surface of the leaf-blades; stems erect, 40-120
cm. high, or sometimes depauperate; leaf-sheaths striate; ligule membranaceous, 1-2 mm. long;
blades as much as 60 cm. long and 7 mm. wide, in depauperate specimens only 5—10 cm. long,
the uppermost reduced, sparsely pilose on the upper surface; panicle dense and spike-like, as
much as 40 cm. long, usually 5-10 cm. long, 3-5 mm. wide, the branches short or the lower,
in robust specimens, as much as 3 cm. long, appressed, the pedicels less than 1 mm. long;
spikelets 2 mm. long, narrowed above, glabrous, prominently nerved; first glume ovate, | mm.
long; second glume and sterile lemma about equal, about 9-nerved, the former gibhous at base,
the sterile palea narrow, about 1 mm. long; fertile lemma 1.5 mm. long, rather narrow, acute,
the margins slightly inrolled.

TYPE LocaLity: Tropical America, the type specimen being from Cayenne. _
Distripution: Isle of Pines; southern Mexico; Panama; northern South America.
ILLUSTRATION: Proc. Biol. Soc. Wash. 21:7. f. 3.

60. HYMENACHNE Beauv. Agrost. 48. 1812.

Perennial swamp grasses, with decumbent rooting stems, erect fertile shoots, broad cordate-
clasping leaf-blades, and narrow or spike-like panicles. Spikelets lanceolate, acuminate. First
glume one third to one half as long as the spikelet, remote, a distinct stipe below the second

302 NORTH AMERICAN FLORA [VoLUME 17

glume. Second glume and sterile lemma 5-nerved, acuminate or attenuate-pointed. Fertile
lemma membranaceous, acuminate, the margins thin, not inrolled, the palea similar to the
lemma in texture, free at the summit.
Type species, Agrostis monostachya Poir.
Panicle spike-iike, dense, the lower branches sometimes distant, appressed; : :
second glume shorter than the sterile lemma; spikelet 4-5 mm. long. 1. H. amplexicaulis.
Panicle narrow but somewhat open, the branches ascending, or only the upper

portion spike-like; second glume nearly as long as the sterile lemma; a
spikelet 3-4 mm. long. 2. H. donacifolia.

1. Hymenachne amplexicaulis (Rudge) Nees, Agrost. Bras.
276. 1829.

Panicum amplexicaule Rudge, Pl. Guian. 21. 1805.
Agrostis monostachya Poir. in Lam. Encye. Suppl. 1: 256. 1810.
Panicum Hymenachne Desv. Opusc. 82. 1831.

Plants essentially glabrous; stems creeping and rooting at base, the erect fertile portion
1—2 meters high; leaf-sheaths longer or shorter than the internodes; ligule a short membrane;
blades 15-30 cm. long, 1-3 em. wide, cordate-clasping at the scarcely narrowed base, the lobes
usually overlapping, ciliate, gradually narrowed to an acuminate apex, the margin smooth
below, scabrous above; panicle spike-like, 10-40 cm. long, 1 cm. wide, the lower branches
sometimes distant, as much as 2 cm. long, appressed; spikelets 4-5 mm. long; first glume about
half as long as the spikelet, 1-nerved, acuminate, scabrous on the keel; second glume on a
stipe 0.5 mm. long, shorter than the sterile lemma, acuminate or somewhat attenuate-pointed,
scabrous on the nerves; sterile lemma similar to the second glume, distinctly attenuate-pointed;
fertile lemma about as long as the second glume, acuminate, membranaceous, the margins
thin, not inrolled, the palea free above.

Tyre LocaLity: British Guiana.

DISTRIBUTION: West Indies and central Mexico to tropical South America.

ILLUSTRATIONS:, Proc. Biol. Soc. Wash. 21: 1. f. 1; Beauv. Agrost. pl. 10, f. 8; Rudge, Pl. Guian.
pl. 27; Trin. Ic. pl. 205.

2. Hymenachne donacifolia (Raddi) Chase, Jour. Wash. Acad.
Sia BB igo ewe

Panicum donacifolium Raddi, Agrost. Bras. 44. 1823.

Panicum auriculatum Willd.; Spreng. Syst. 1: 322. 1825.

Panicum polystachyum Presl, Rel. Haenk. 1: 312. 1830.
Hymenachne patula Fourn. Mex. Pl. Gram. 37. 1886.

Hymenachne auriculata Chase, Proc. Biol. Soc. Wash. 21:5. 1908.

Foliage characters similar to those of H. amplexicaulis; panicle narrow, 20-40 cm. long,
the upper portion spike-like, the lower portion loose or interrupted, the branches 3-10 cm. long,
ascending or appressed; spikelets 3-4 mm. long; first glume about one third the length of the
spikelet, 3-nerved; second glume and sterile lemma somewhat unequal, acuminate, or the
lemma attenuate-pointed, slightly scabrous on the nerves, the glume short-stiped; fertile
lemma nearly as long as the second glume, acuminate.

TYPE LOCALITY: Near Rio Janeiro, Brazil.
DIsTRIBUTION: Cuba; Panama and tropical South America.

61. HOMOLEPIS Chase, Proc. Biol. Soc. Wash. 24: 146. 1911.

Perennial grasses with long leafy runners, rooting at the nodes, more or less decumbent
flowering stems, narrowly lanceolate blades, and narrow panicles. Spikelets rather large,
subfusiform. First and second glume equal or the first slightly longer, 7—-9-nerved, the pair
wholly covering the sterile and fertile florets. Sterile lemma nearly as long as the glumes,
broad, infolding the fertile lemma, and inclosing a narrow hyaline palea and sometimes a
staminate flower. Fruit elliptic, pointed, smooth and shining, the lemma and palea less
indurate than in Panicum, the margins of the lemma flat.

Type species, Panicum aturense H.B.K.

Sterile lemma villous; base of panicle branches glabrous or nearly so. 1. H. aturensis.
Sterile lemma glabrous; base of panicle branches pubescent. 2. H. isocalycia.

Part 4, 1931] POACEAE 303

1. Homolepis aturensis (H.B.K.) Chase, Proc. Biol. Soc. Wash.
24: 146. 1911.
Panicum aturense H.B.K. Nov. Gen. & Sp. 1: 103. 1815.
Panicum viridiflorum Nees, Agrost. Bras. 135. 1829.
Panicum blepharophorum Presl, Rel. Haenk. 1:312. 1830.

Panicum tumescens Trin. Mém. Acad. St.-Pétersb. VI. Sci. Nat. 32: 316. 1834.
Milium orinoccense Willd.; Steud. Nom. Bot. ed. 2. 2: 146, assynonym. 1841.

Stems 1-5 dm. high from decumbent rooting bases or stolons as much as 2 m. long,
glabrous; foliage light- or yellowish-green; leaf-sheaths compressed-keeled, striate, glabrous,
the margins villous, the surface near the margins more or less papillose-hispid, usually a
hispidulous line at the collar; blades narrowly lanceolate, flat, thin, 5-15 cm. long, or those
of the runners only 2 cm. long and the uppermost culm-blade much reduced, 10-15 mm. wide,
truncate or cordate at base, acuminate, scabrous and minutely ciliate on the margin, glabrous
or sometimes pubescent; panicles exserted from the elongate somewhat inflated upper sheath,
narrowly elliptic, rather compact (open at anthesis), 5-10 cm. long, the slender branches
ascending, floriferous from near the base, the color olive- or bronze-green; spikelets elliptic,
5-8 mm. long, narrowed at base, acuminate at apex, glabrous, striate-nerved, the pedicels
often flexuous, the minimum length about 3 mm.; second glume villous at base on margin
where inclosed by first glume; sterile lemma softly appressed-villous.

TYPE LocALity: Atures, Venezuela.
DISTRIBUTION: Southern Mexico to Brazil and Bolivia.
ILLUSTRATIONS: H.B.K. Nov. Gen. & Sp. pl. 33; Proc. Biol. Soc. Wash. 24: 147. f. 12.

2. Homolepis isocalycia (G. Meyer) Chase, Proc. Biol. Soc.
Wash. 24: 147. 1911.
Panicum isocalycium G. Meyer, Fl. Esseq. 59. 1818.
Panicum Langei Fourn. Mex. Pl. Gram. 23. 1886.

Stems 3-7 dm. tall, from a creeping or stoloniferous rooting base, glabrous; leaf-sheaths
glabrous, pubescent on collar and margin; blades narrowly oblong-lanceolate, 8-18 em. long,
7-15 mm. wide, cordate at base, acuminate at apex, glabrous, ciliate and scabrous on the
margin; panicle ovoid, 5-10 cm. long, rather loosely flowered, the slender flexuous main branches
ascending, pubescent at base, the spikelets appressed, the pedicels about 2 mm. long; spikelets
5-6 mm. long, more turgid than in H. aturensis, acute but scarcely acuminate; sterile lemma
glabrous.

TYPE Locality: British Guiana.
DistRIBUTION: Vera Cruz; British Guiana to Brazil.

62. SCUTACHNE Hitche. & Chase; Chase, Proc. Biol. Soc.
Wash. 24: 148. 1911.

Erect tufted perennial grasses, with linear leaf-blades and narrow panicles. Spikelets fusi-
form, acuminate, the base attenuate, the internodes of the rachilla elongate, the lower-
most forming a stipe, the first glume adnate to it. First glume membranaceous, about half
the length of the spikelet, broad, the margins connate below. Second glume and sterile lemma
subequal, a manifest internode of the rachilla between them, leathery-indurate, brown or
brownish, 5-nerved, the lemma inclosing a palea of similar texture, and sometimes a staminate
flower. Fruit but slightly more indurate than the second glume and sterile lemma, elliptic
in outline, the lemma abruptly acuminate into a slender, densely pubescent tip, the margins
slightly inrolled below, membranaceous, flat and pubescent above, the summit of the palea
usually inclosed, densely pubescent on the margin.

Type species, Panicum durum Griseb.

Stems leafy, the blades elongate; panicles terminal only, of several branches. 1. S. dura.

Stems nearly naked, the leaves reduced to the sheaths or nearly so, the basal ;
leaves with blades; panicles terminal and axillary, simple. 2. S. amphistemon.

304 NORTH AMERICAN FLORA [VOLUME 17

1. Scutachne dura (Griseb.) Hitchc. & Chase; Chase, Proc. Biol.
Soc. Wash. 24: 149. 1911.

Panicum durum Griseb. Mem. Am. Acad. IT. 8: 533. 1862.
Alloteropsis dura Hitche. Contr. U.S. Nat. Herb. 12: 211. 1909.

Stems 3-5 dm. tall, glabrous or the nodes sometimes puberulent; leaf-sheaths glabrous;
ligule very short; blades as much as 35 cm. long, 4-8 mm. wide, the uppermost only 3-4 cm.
long, erect, the upper rounded or truncate at base, the lower gradually narrowed below, rather
firm, glabrous except the retrorsely scabrous margin; panicles long-exserted, 5-10 cm. long,
the branches puberulent, ascending or sometimes spreading, 2—4 cm. long, the spikelets short-
pedicelled and appressed; spikelets 5-6 mm. long, narrowed at the base, acuminate; first
glume thin, light-colored, contrasting with the remaining darker part of the spikelet, puberulent
or nearly glabrous, distinctly 3-nerved, with 1 or 2 pair of indistinct intermediate nerves; second
glume and sterile lemma pubescent.

TYPE LOCALITY: Eastern Cuba.
DistRIBUTION: Cuba, Hispaniola, and Jamaica.
ILLUSTRATION: Proc. Biol. Soc. Wash. 24: 149. f. 13.

2. Scutachne amphistemon (Wright) Hitche. & Chase; Chase, Proc.
Biol. Soc. Wash. 24: 149. 1911.
Panicum amphistemon Wright; Sauv. Anal. Acad. Ci. Habana 8: 207. 1871.
Alloleropsis amphistemon Hitche. Contr. U.S. Nat. Herb. 12: 211. 1909.

Stems 25-40 cm. tall, glabrous, the leaves clustered at the base, the flowering stems some-
what branched and geniculate; basal blades 8-12 cm. long, narrowed at base, rounded at
apex, firm, striate, the cauline leaves distant, reduced to sheaths; panicles terminating the main
stem and the few distant branches, narrow, few-flowered, the few short branches appressed,
bearing a pair of spikelets, one nearly sessile, the other with a pedicel about its own length;
spikelets narrow, about 7 mm. long; first glume only slightly lighter in color than the minutely
puberulent second glume and sterile lemma.

Typt Locatity: Eastern Cuba.
DISTRIBUTION: Cuba.

63. ISACHNE R. Br. Prodr. 196. 1810.

Perennial grasses with simple or usually branching stems, flat striate-nerved leaf-blades,
and paniculate inflorescence. Spikelets obovoid to subglobose. Glumes membranaceous,
about equal and as long as the fruits or at maturity exceeded by these. Lower floret perfect
or staminate, its lemma and palea indurate and similar in form and texture to those of the
upper floret. Both florets (or fruits) plano-convex, obtuse, equal in size or the upper shorter,
the pair usually remaining attached together by the minute rachilla joint below the upper
floret.

Isachne polygonoides is exceptional in that the lower floret is unlike the upper. In all
the species the lower floret of some of the spikelets may fail to perfect a grain. When sterile
the floret is often longer and the lemma less convex than when fertile, the spikelets on the same
panicle thus having a somewhat diverse appearance.

Type species, Isachne australis R. Br.

Florets appressed-pubescent.

Blades ovate-clasping. 1. I. polygonoides.
Blades linear. 2. I. leersioides.
Florets glabrous, or the palea minutely hispidulous.
Panicles contracted, spike-like, not more than 3 cm. long, the branches ap-
pressed or the lower sometimes ascending; plants low and spreading. 3. I. pygmaea.

Panicles open, the branches spreading or ascending. 3

Blades about 3 mm. wide, thick, rigid, pungent, with conspicuously

thickened midrib. 4. I. rigidifolia.
Blades qostly 5-20 mm. wide, firm but not pungent nor with thickened
midrib.
Stems trailing; blades rarely more than 5 cm. long. 5. I. rigens.

Stems clambering; blades mostly more than 5 cm. long.
Glumes pubescent; blades firm, not more than 12 em. long and
1 cm. wide. 6. I. angustifolia

Part 4, 1931] POACEAE 305

Glumes glabrous (rarely obscurely pubescent at tips); blades
mostly more than 15 cm. long and 1.5 cm. wide.
Spikelets aggregate toward the ends of the branches and
branchlets. 7. I. arundinacea.
Spikelets not aggregate; panicle loosely flowered. 8. I. disperma.

1. Isachne polygonoides (Lam.) Déll, in Mart. Fl. Bras. 27:
His, INSITE
Panicum polygonoides Lam. Encyc. 4: 742. 1797.
Panicum trachyspermum Nees, Agrost. Bras. 212. 1829.
Tsachne trachysperma Nees, in Seem. Bot. Voy. Herald 224. 1854.

Stems decumbent, branching and spreading, rooting at the lower nodes, the flowering
branches ascending, 1-3 dm. tall, glabrous, the nodes glabrous but the base of the sheath hispid;
leaf-sheaths mostly shorter than the internodes, papillose-hispid or glabrate; ligule a ring of
stiff hairs about 2 mm. long; blades ovate or ovate-lanceolate, 2-5 cm. long, 7-17 mm. wide,
cordate-clasping and ciliate at base, acute or somewhat acuminate at apex, striate-nerved,
scabrous on upper surface, puberulent or pubescent beneath; panicles numerous, ovoid,
partially inclosed in the sheaths or finally exserted, the branches and branchlets slender,
spreading, stiff and more or less implicate, the pedicels 2-4 mm. long, enlarged at the extremity;
spikelets about 1.5 mm. long, first glume glabrous; second glume sparsely hispidulous; lower
floret lanceolate, only slightly turgid, greenish, glabrous, cartilaginous rather than indurate,
exceptional for the genus in resembling the glumes rather than the upper floret; upper floret
pubescent, whitish, indurate, hemispherical.

TYPE LocaLity: Cayenne, French Guiana.

DIsTRIBUTION: Guatemala to Brazil.
ILLustRaATION: Contr. U. S. Nat. Herb. 22: pl. 25.

2. Isachne leersioides Griseb. Mem. Am. Acad. II. 8: 533. 1862.

Stems slender, branched, trailing, glabrous, striate, 1-2 m. long; leaf-sheaths on the main
stems much shorter than the elongate internodes, overlapping on the flowering branches,
appressed papillose-hispid or nearly glabrous; ligule a very short membrane, ciliate with stiff
hairs about 1 mm. long; blades linear, 5-15 cm. long, 0.5—4 mm. wide, long-acuminate, striate-
nerved, cartilaginous-margined, scabrous or hispidulous on both surfaces; panicles terminating
the branches, ovoid or oblong, 5-15 cm. long, as much as 7 cm. wide, the branches mostly
single, rather stiffly ascending or spreading, bearing from near the base stiffly spreading
branchlets, the spreading pedicels 2-3 mm. long; spikelets about 1 mm. long; glumes
hispidulous; florets appressed-pubescent.

Type Locatity: Eastern Cuba.

DIsTRIBUTION: Cuba.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 26.

3. Isachne pygmaea Griseb. Fl. Brit. W. Ind. 553. 1864.

Stems low, the slender branches spreading, glabrous, the flowering shoots usually less
than 15 cm. tall; leaf-sheaths glabrous, ciliate on the margins; ligule a very short hispidulous
ring; blades narrowly oblong-lanceolate, 0.5-2 cm., or rarely 3 cm. long, rarely more than 2 mm.
wide, spreading, glabrous or puberulent, the white margin cartilaginous and somewhat scabrous;
panicles long-exserted, narrow, compact and spike-like, usually less than 2 cm. long, the lower
branches short and somewhat distant, appressed or rarely ascending; spikelets about 1.3 mm.
long, nearly sessile; glumes glabrous, about two thirds as long as the spikelet; florets glabrous.

TYPE LOCALITY: Jamaica.

DistrRisuTIon: Central Jamaica.
ILLustTRATION: Contr. U. S. Nat. Herb. 22: pl. 27.

306 NORTH AMERICAN FLORA [VoLUME 17

4. Isachne rigidifolia (Poir.) Urban, Symb. Ant. 4: 85. 1903.

Agrostis rigidifolia Poir. in Lam. Encyc. Suppl. 1: 257. 1810.

Milium rigidum Poir. in Lam. Encyc. Suppl. 1: 257, as synonym. 1810.
Milium rigidifolium R. & S. Syst. Veg. 2: 319. 1817.

Panicum rigidifolium Kunth, Rév. Gram. 37. 1829.

Panicum arbusculum Sieber; Griseb. Fl. Brit. W. Ind. 553, as synonym. 1864.

Stems spreading and branching, the flowering shoots firm and rigid, 1.5—4 dm. tall; leaf-
sheaths glabrous, stiffly ciliate on the margin, overlapping on the flowering shoots; ligule a
very short lacerate or ciliate membrane; blades oblong, 2-4 cm. long, 2-4 mm. wide, firm,
rigidly spreading, pungently pointed, glabrous, the cartilaginous margin and thick midrib
whitish; panicles long-exserted, open, oblong, rather narrow, 2—5 cm. long, branches ascending
or spreading, bearing the branchlets mostly on the lower side, the pedicels rigid, 1-2 mm. long;
spikelets about 2 mm. long, purplish, borne obliquely upon the pedicels; glumes glabrous or
sparsely appressed-hispidulous near apex; florets smooth.

TYPE LOCALITY: Santo Domingo.
DISTRIBUTION: Hispaniola, Saba, Guadeloupe, and Martinique.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: pl. 28.

5. Isachne rigens (Sw.) Trin. Gram. Pan. 252. 1826.
Panicum rigens Sw. Prodr. 23. 1788.

Stems tufted, glabrous, slender, wiry, trailing, 1-2 m. long, as much as 1 mm. thick, the
numerous flowering shoots curving upward, 1-3 dm. long; leaf-sheaths glabrous or puberulent,
ciliate on the margin; ligule a ring of stiff hairs about 0.5 mm. long; blades narrowly oblong-
lanceolate, 2-5 cm. long, 2-5 mm. wide, moderately firm but not stiff and rigid, scabrous on
both surfaces and on the cartilaginous margin; panicles ovoid or oblong, 2—5 cm. long, the
branches and branchlets stiffly ascending or spreading, the pedicels 1-2 mm. long; spikelets
1.8-2 mm. long; glumes minutely hispidulous; rachilla between the two florets minutely villous;
palea of upper floret sparsely appressed-hispidulous.

‘TYPE LOCALITY: Jamaica.
DISTRIBUTION: Jamaica; also from Venezuela and Colombia.
ILLusTRATION: Contr. U. 5. Nat. Herb. 22: pl. 29.

6. Isachne angustifolia Nash, Bull. Torrey Club 30: 377. 1903.

Stems clambering, as much as 2 m. long and 2 mm. thick, hard and wiry with a long
naked base, branching from the upper nodes, the branches long, leafy, nearly parallel, bearing
secondary branches toward the ends, the whole forming a wide flabellate or loosely corymbose
mass, in its most characteristic development pushing through the jungle of stream-bank or
trail-side and hanging over bushes; leaf-sheaths appressed pilose with papillate hairs or
roughened with papillae, or glabrous, the margin ciliate; ligule a ring of very short stiff hairs
less than 0.5 mm. long; blades narrowly lanceolate, 3-15 cm. long, but mostly more than 5 em.
long, 5-12 mm. wide, rather firm and stiffly spreading, scaberulous or glabrate, papillose-
ciliate at base or papillose only; panicles ellipsoid or oblong, as much as 15 cm. long, the
branches stiffly ascending or finally spreading, the branchlets and pedicels finally divaricate,
these and the main axis scabrous; spikelets about 1.5 mm. long; glumes minutely hispidulous
toward the tip; florets and rachilla glabrous.

TYPE LOCALITY: El Yunque, Porto Rico.
DistRIBUTION: Porto Rico and Guadeloupe.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: pl. 30.

7. Isachne arundinacea (Sw.) Griseb. Fl. Brit. W. Ind. 553. 1864.

Panicum arundinaceum Sw. Prodr. 24. 1788.
Panicum glaucescens H.B.K. Nov. Gen. & Sp. 1: 104. 1815.
Isachne panicea Trin. Gram. Pan. 253. 1826.

Stems climbing among shrubs or small trees to a height of as much as 6 m., as much as
5 mm. thick at base, with strong canes and elongate branches; leaf-sheaths glabrous, or rarely
slightly scabrous, ciliate on the margin, sometimes a little papillose near the summit, over-

Part 4, 1931] POACEAE 307

lapping on the flowering shoots; ligule of stiff hairs as much as 5 mm. long; blades narrowly
lanceolate, as much as 20 cm. long and 2 cm. wide, long-acuminate, scabrous, sometimes
becoming smoothish, often papillose on margin at base; panicles ovoid or ellipsoid, as much as
12 cm. long and 10 cm. wide, rounded at summit, the branches ascending or the lower finally
spreading, branched from about the middle, the spikelets somewhat aggregate on the branchlets,
the panicle thus rather compactly flowered at the periphery, the pedicels 0.5—2 mm. long; spike-
lets about 1.5 mm. long; glumes glabrous or with a few short stiff hairs at the summit; florets
glabrous.

TYPE LOCALITY: Jamaica.
DISTRIBUTION: Jamaica; Vera Cruz to Venezuela and Bolivia.
ILLusTRATION: Contr. U.S. Nat. Herb. 22: pl. 31.

8. Isachne disperma (Lam.) Déll, in Mart. Fl. Bras. 27: 274. 1877.

Panicum dispermum am. Tab. Encye. 1: 173. 1791.

Panicum multinerve Desv.; Poir. in Lam. Encyc. Suppl. 4: 279. 1816.
Panicum confertum Desy.; Poir. in Lam. Encyc. Suppl. 4: 279. 1816.
Isachne (?) dubia Kunth, Réy. Gram. 42. 18

Aspect of plant as in J. arundinacea; leaf-sheaths glabrous or rarely papillose-hispidulous;
ligule hairs as much as 2 mm. long; blades averaging larger than in J. arundinacea, glabrous,
scabrous toward apex; panicles as much as 20 cm. long, the branches and branchlets spreading,
the spikelets in twos or threes at the ends of the branchlets, the panicle thus more open and
more equally flowered than in I. arundinacea, the spikelets not strongly aggregate toward the
periphery; spikelets slightly more than 1 mm. long; glumes and florets glabrous.

TYPE LocaLity: Tropical America.

DISTRIBUTION: Lesser Antilles, from St. Kitts to Tobago.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: pl. 32.

64. OPLISMENUS Beauv. Fl. Oware 2:14. pl. 68, f. 1. 1809.
Orthopogon R. Br. Prodr. 194. 1810.
Hippagrostis Kuntze, Rev. Gen. 776. 1891.

Usually weak, freely branching, creeping annuals or perennials with erect or ascending
flowering shoots, flat thin ovate or lanceolate leaf-blades and one-sided spike-like racemes along
amain axis. Spikelets terete or somewhat compressed laterally, subsessile, in pairs or solitary
in two rows on one side of a narrow scabrous or hairy rachis. Glumes subequal, emarginate
or entire, the midnerve extending into an awn, that of the first longer. Sterile lemma exceeding
the glumes and fruit, notched or entire, mucronate or short-awned, inclosing a hyaline palea.
Fruit elliptic, acute, the lemma very convex or boat-shaped, the firm margins clasping the
palea, inrolled.

Type species, Oplismenus africanus Beauv.

Awns antrorsely scabrous; plants annual. 1. O. Burmanni.
Awns smooth or obscurely roughened; plants perennial.
Rachis of racemes mostly 2-3 mm. long, bearing usually not more than 5
spikelets; leaf-blades 1-3 cm. long, 4-10 mm. long. 2. O. setarius.

Rachis of lower racemes more than | cm. long; bearing usually more than 8
spikelets; leaf-blades mostly more than 4 cm. long, 1-2 cm. wide.

Racemes closely flowered, the lower 1—2 cm. long. 3. O. hirtellus.
Racemes loosely flowered, the lower 2-5 cm. long, the lower pairs of ;
spikelets as much as ] cm. apart. 4. O. rariflorus.

1. Oplismenus Burmanni (Retz.) Beauv. Agrost. 54. 1812.

Panicum hirtellum Burm. F1. Ind. 24. 1768. Not P. hirtellum L. 1759.
Panicum Burmanni Retz. Obs. 3:10. 1783.

Panicum bromoides Lam. Tab. Encye. 1: 170. 1791.

Oplismenus bromoides Beauv. Agrost. 54. 1812. -

Panicum album Poir. in Lam. Encyc. Suppl. 4: 274. 1816.

Oplismenus albus R. & S. Syst. Veg. 2: 890. 1817.

Orthopogon Burmanni Trin. Fund. Agrost. 181. 1820.

Oplismenus affinis Schultes, in R. & S. Syst. Veg. Mant. 2: 273. 1824.
Panicum lappaceum Willd.; Spreng. Syst. 1: 306, as synonym. 1825.
Oplismenus Humboldtianus Nees, Agrost. Bras. 264. 1829.

308 NORTH AMERICAN FLORA [VOLUME 17

Positin Peagcot Steud. Syn. Gram. 44. 1854.

Panicum Sanctae-Marthae Steud. Syn. Gram. 45. 1854.

Panicum Schultesii Steud. Syn. Gram. 46. 1854.

Oplismenus Humboldtianus muticus Fourn. Mex. Pl. Gram. 37. 1886.

Plants annual: stems slender, glabrous or pubescent in lines or sometimes pubescent all
over, the flowering shoots as much as 4 dm. long, usually 1-2 dm. long, ascending or nearly
prostrate; leaf-sheaths glabrous or papillose-hispid, striate, ciliate on the margin, villous on
the collar; ligule a very short membrane, ciliate with hairs about 1 mm. long; blades ovate to
ovate-lanceolate, mostly 2-5 cm. long, sometimes longer, 1—-1.5 cm. wide, thin, more or less
pubescent or hispid on both surfaces, especially toward the base, usually undulate on the
margin; panicle ovoid to linear, mostly long-exserted, mostly compact, 2-5 cm. long, sometimes
as much as 10cm. long, the spikes more distant, mostly nodding, the main axis villous; racemes
3 to several, appressed or ascending, rather short and thick, white and silky, mostly 8-15 mm.
long, the spikelets closely set and nearly sessile on the rachis, this softly villous and also beset,
especially at the base of the spikelets, with stiff papillose hairs 2-3 mm. long; spikelets com-
pressed, whitish, several to many on each rachis; first glume 3-nerved, half as long as sterile
lemma, rather sparsely appressed villous, notched at apex, the midnerve extending as a slender
straight antrorsely scabrous awn 10-15 mm. long; second glume similar to the first, a little
longer, 5-nerved, the awn shorter; sterile lemma similar to the glumes, about 3 mm. long,
compressed above, nearly terete below, about 7-nerved, the lower half often copiously villous,
the awn shorter than those of the glumes, commonly 1-3 mm. long; fruit smooth and shining,
about as thick as wide, pale or brownish, about 2 mm. long.

TYPE LocaLity: India.

DISTRIBUTION: Tropics of both hemispheres, introduced in America; common from southern
Mexico to Brazil; Cuba and Hispaniola.

ILLUSTRATIONS: Burm. Fl. Ind. pl. 12, f. 1; Beauv. Fl. Oware pl. 68, f. 1; Trin. Ic. pl. 193;

rot Mus. Publ. Bot. 7: 37; Proc. Biol. Soc. Wash. 24: 152. f. 15; Contr. U. S. Nat. Herb. 22: 125.
Bras :

2. Oplismenus setarius (Lam.) R. & S. Syst. Veg. 2: 481. 1817.

Panicum setarium Lam. Tab. Encye. 1: 170. 1791.
Orthopogon parvifolium Nutt. Gen. 1:55, errata. 1818.
Orthopogon setarius Spreng. Syst. 1: 306. 1825.

Oplismenus parvifolius Kunth, Rév. Gram. 1:45. 1829.
Panicum Nutiallianum Steud. Nom. Bot. ed. 2.2: 260. 1841.

Stems slender and lax, the flowering branches ascending or nearly prostrate, usually not
more than 1-2 dm. long, sometimes as much as 3 dm., glabrous or pubescent in lines; leaf-
sheaths glabrous, villous on the margin, pubescent about the collar; ligule a very short ciliate
membrane; blades ovate to ovate-lanceolate, thin, mostly 1-3 cm. long, 4-10 mm. wide, sparsely
pilose on both surfaces or glabrate; panicle long-exserted, usually not more than 5 cm. long,
rarely as much as § cm., the axis scabrous or puberulent; racemes usually 3-5, rarely as many
as 8, short and globose, distant or the upper approximate, the lower internode sometimes as
much as 2 em. long, the rachis usually 2-3 mm. long, rarely as much as 5 mm. long (or a little
longer in some United States specimens), puberulent, pubescent or villous at base; spikelets
rarely as many as 8 on a rachis, usually not more than 5, the lowermost sometimes reduced to
awns; glumes more than half as long as the sterile lemma, appressed-hispidulous, often more
or less pilose along the margin, more or less notched at apex, the first 3-nerved, the awn mostly
4-8 mm. long, smooth, the second 5-nerved, the awn much shorter, usually 2-3 mm. long; -
sterile lemma 2-3 mm. long, 7-nerved, appressed-pilose above, the awn short or wanting;
fruit about 2.5 mm. long.

TYPE LocaLity: Tropical America.

DistriBuTion: Along the coast, North Carolina to Florida, Arkansas, and Texas; southern

Mexico to Honduras; West Indies; also from Trinidad to Paraguay.

ILLUSTRATIONS: "Bull. U.S. Dep. Agr. Agrost. 17: 104. f. 400 as O. hirtellus); Bull. U.S. De
Agr. 772: 239. f. 145; Contr. U.S. Nat. Herb. 22: 128. f. 22. : ’ a Ps

Part 4, 1931] POACEAE 309

3. Oplismenus hirtellus (L.) Beauv. Agrost. 54, 168. 1812.

Panicum hirtellum L. Syst. Nat. ed. 10. 870. 1759.

Milium undulatifolium Moench, Meth. 202. 1794.

Orthopogon hirtellus Nutt. Gen. 55. 1818.

Panicum velutinum G. Meyer, Fl. Esseq. 51. 1818.

Oplismenus brasiliensis Raddi, Agrost. Bras. 40. 1823.

Oplismenus velutinus Schultes, in R. & S. Syst. Veg. Mant. 2: 271. 1824.
Orthopogon cubensis Spreng. Syst. 1: 307. 1825.

Echinochloa cubensis Schultes, in R. & S. Syst. Veg. Mant. 3: Addit. 596. 1827.
Oplismenus cubensis Kunth, Rév. Gram. 45. 1829.

Panicum cubense Steud. Nom. Bot. ed. 2.2: 255. 1841.

Panicum Raddianum Steud. Syn. Gram. 45. 1854.

Oplismenus chondrosioides Fourn. Mex. Pl. Gram. 39. 1886.

Plants perennial; stems widely creeping and branching, the flowering ones usually erect
from an ascending base, as much as 7 dm. tall but usually about 3 dm., glabrous or somewhat
pubescent; leaf-sheaths glabrous or densely papillose-hispid; ligule membranous, about 0.5 mm.
long, short-ciliate; blades lanceolate or oblong-lanceolate, mostly 5-10 cm. long, 1-2 cm. wide,
rather abruptly narrowed above into an acuminate apex, glabrous or pubescent, papillose-
ciliate at base; panicle long-exserted, 5 to 10 cm. long, the main axis pubescent or the lower
part nearly glabrous; the lowest internode commonly about 2 cm. long; racemes mostly 3-7,
ascending or spreading, rather distant, compact or sometimes rather loose, the lowermost
1-2 em. long, the rachis pubescent and also papillose-hispid; spikelets in pairs, the pairs alter-
nating on the two sides of the triangular rachis, appressed-villous or hispid or nearly glabrous,
green or, especially the awns, purple; glumes nearly equal, a little more than half as long as
the sterile lemma, more or less notched at apex or tapering into the rather stout smooth awn,
the first 5-nerved with an awn 5-10 mm. long, the second 7-nerved, the awn once or twice as
long as the glume, sometimes shorter, sterile lemma 2.5—3 mm. long, 7-nerved, usually notched
at apex, the awn mostly 1-2 mm. long, sometimes wanting; fruit 2—-2.5 mm. long.

TYPE LOCALITY: Jamaica.

DISTRIBUTION: Southern Mexico and the West Indies to Argentina.
ILLUSTRATIONS: Field Mus. Publ. Bot. 7: 36; Contr. U.S. Nat. Herb. 22: 130. f. 23.

4. Oplismenus rariflorus Presl, Rel. Haenk. 1: 320. 1830.
Oplismenus latifolius Haenke; Steud. Nom. Bota: 2.2:220, assynonym. 1841.

Panicum parciflorum Steud. Syn. Gram. 45.
Oplismenus Liebmanni Fourn. Mex. Pl. Gram. 38. 1886.
Oplismenus Thiebauti Fourn. Mex. Pl. Gram. 39. 1886.
Stems sparingly branched, ascending from a decumbent base, as much as 5 dm. tall but
mostly less, glabrous or sometimes pubescent; leaf-sheaths glabrous or pubescent, densely
ciliate on the margin, villous on the collar; ligule a short ciliate membrane; blades lanceolate or
elliptic-lanceolate, mostly about 4~7 cm. long, rarely as much as 13 cm., 1-2 em. wide, thin,
glabrous, scabrous, or sparsely pilose; panicle long-exserted, the main axis 5-15 cm. long,
scabrous; racemes several, the lower distant, 2-5 cm. long or even 7 cm., ascending, loosely
flowered, the rachis scabrous, often villous at base and pilose at the insertion of the spikelets;
spikelets scattered, the lower pairs as much as | cm. apart; glumes more than half as long as
the sterile lemma, glabrous or hispidulous, rarely pilose, tapering into a smooth awn, the first
3-nerved, the awn 3-8 mm. long, rarely longer, the second 5-nerved, the awn very short or
wanting; sterile lemma 3 mm. long, mostly awnless; fruit 2.5 mm. long.

TypE Locatity: Acapulco, Mexico.
DISTRIBUTION: Mexico and Guatemala; also in Ecuador and Peru.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: 132. f. 24.

65. ECHINOCHLOA Beauv. Agrost. 53. 1812.

Anaual or perennial, coarse, often succulent grasses with linear flat blades and narrow
panicles consisting of several spike-like racemes along a main axis. Spikelets plano-convex,
often spiny-hispid, subsessile, in pairs or in irregular clusters crowded on one side of the panicle
branches. First glume about half as long as the spikelet, pointed. Second glume and sterile
lemma equal, stiffly hispidulous on the nerves, usually scabrous on the internerves, pointed,

310 NORTH AMERICAN FLORA [VoLUME 17

mucrenate or the glume short-awned, the lemma mucronate or awned, sometimes conspicuously
so, inclosing a membranaceous palea and sometimes a staminate flower. Fruit plano-convex,
the lemma and palea smooth and shining, acuminate-pointed, the lemma margins inrolled
below, flat above, the apex of the palea not inclosed.

Type species, Panicum Crusgalli L.

Ligule a dense line of stiff yellowish hairs; plants perennial.
Fruit about 2.5 mm. long; awn of sterile lemma less than 2 mm. long. 1. E. pyramidalis.
Fruit about 4 mm. long.

Awn of sterile lemma generally 5-10 mm. long; sterile floret staminate.
Awn of sterile lemma generally 4-5 cm. long; sterile floret neuter.

Ligule wanting, the ligular area sometimes pubescent; plants annual.

Racemes simple, rather distant, 1-2 cm. long; spikelets crowded in about 4
rows, the awn of the sterile lemma reduced to a short point; blades 3-6
mm. wide. 4. E. colonum.

Racemes more or less branched, usually more than 2 cm. long; spikelets

irregularly crowded and fascicled, usually not arranged in rows, the
awn of the sterile lemma variable; blades usually more than 5 mm.
wide.
Sterile floret staminate.
Sterile floret neuter.
Fruit 2.5-3 mm. long.
Leaf-sheaths smooth; awns variable, but the panicle not a dense
mass of long-awned spikelets.
Spikelets about 3 mm. long, excluding awns; panicles erect,
or, when large and heavy, nodding at tip. 6. E. Crusgalli.
Spikelets about 2.5 mm. long, excluding awn; panicles
nodding, soft, pinkish. ie
Leaf-sheaths, at least the lower, hispid or scabrous; panicle dense,
the spikelets long-awned.
Fruit about 4 mm. long.

E. polystachya.
. holciformis.

Wr
leslle:

on
re]

. paludigena.

. Crus-pavonis.

. Walteri.
. oplismenoides.

oo
hm ob

1. Echinochloa pyramidalis (Lam.) Hitche. & Chase, Contr. U. S.
Nat. Herb. 18: 345. 1917.

Panicum pyramidale Lam. Tab. Encye.1:171. 1791.
Panicum spectabilis guadeloupense Hack. Notizbl. Bot. Gart. Berlin 1: 328. 1897.
Echinochloa guadeloupensis Wiegand, Rhodora 23: 63. 1921.

Plants perennial; stems erect, rather fleshy, 1.5—2.5 m. tall, glabrous; leaf-sheaths glabrous;
ligulesa dense row of stiff yellowish bristles 1-2 mm. long; blades 4-6 dm. long, 5-10 mm. wide,
glabrous above, scabrous on the margin and on the nerves beneath; panicle 2-4 dm. long,
the axis scabrous; racemes numerous, ascending, 2-7 cm. long, single or somewhat fascicled,
distant below but overlapping, stiffly pilose at base and sparsely so along the scgbrous or
hispidulous rachis; spikelets about 3 mm. long, rather loosely arranged along the rachis, scabrous
or slightly hispidulous on the nerves, glabrous or nearly so on the internerves; sterile floret
staminate, the lemma mucronate or with an awn 1-2 mm. long; fruit about 2.5 cm. long,
mucronate.

TYPE Locatity: Africa.
DistRiBuTION: Tropical Africa; introduced in Guadeloupe.
ILLUSTRATIONS: Kunth, Rév. Gram. pl. 23; Contr. U.S. Nat. Herb. 22: 134. f. 25.

2. Echinochloa polystachya (H.B.K.) Hitche. Contr. U. S. Nat.
Herb. 22: 135. 1920:

Oplismenus pclystachyus H.B.K. Nov. Gen. & Sp. 1: 107. 1816.

Panicum spectabile Nees; Trin. Gram. Pan. 138. 1826.

Echinochloa spectabilis Link, Hort. Berol. 2: 209. 1833.

Orthopogon hirsutus Spreng.; Steud. Nom. Bot. ed. 2. 2: 234, assynonym. 1841.
Panicum phyllanthum Steud. Syn. Gram. 47. 1854.

Panicum Bonplandianum Steud. Syn. Gram. 48. 1854.

Plants perennial; stems coarse, 1-2 m. tall from a long creeping rooting base, glabrous,
the nodes densely hispid with appressed yellowish hairs; leaf-sheaths glabrous or papillose-
hispid; ligule a dense line of stiff yellowish hairs as much as 4+ mm. long; blades as much as 2.5
cm. wide, scabrous on the margin and upper surface; panicle 1-3 dm. long, rather dense, the
axis angled, very scabrous; racemes ascending, the lower mostly 3-6 cm. long, densely hispid

Part 4, 1931] POACEAE 311

at base, the rachis very scabrous and more or less papillose-hispid; spikelets rather closely set,
nearly sessile, about 5 mm. long; sterile floret staminate, the awn 2-10 mm. long; fruit rather
soft, about 4 mm. long, extending into a point about 0.5 mm. long.

TYPE LOCALITY: Venezuela.
DISTRIBUTION: Mexico and the West Indies to Argentina.
ILLustRations: Trin. Ic. pl. 166; Contr. U. S. Nat. Herb. 22: 135. f. 2

3. Echinochloa holciformis (H.B.K.) Chase, Proc. Biol. Soc.
Wash. 24: 155. 1911.

Oplismenus holciformis H.B.K. Nov. Gen. & Sp. 1: 107. 1815.
Orthopogon holciformts Spreng. Syst. Veg. 1: 307. 1825.

Panicum holciforme Steud. Syn. Gram. 48. 1854.

Berchtoldia holciformis Fourn. Mex. Pl. Gram. 41. 1886.

Plant perennial; stems erect, sometimes with a decumbent rooting base, stout, succulent,
as much as 2 m. ta!l and 1.5 cm. thick at base, glabrous; leaf-sheaths glabrous; ligule a dense
line of stiff hairs, long on the lower leaves, short on the upper leaves; blades mostly 8-15 mm.
wide, scabrous on margin and upper surface; panicle dense, or interrupted below, nodding,
as much as 4 dm. long, the axis scabrous, densely hispid around the base of the branches;
racemes appressed, single or fascicled, the lower as much as 10 cm. long, the rachis scabrous
and hispid; spikelets rather closely arranged, nearly sessile, about 5 mm. long, fusiform, green
or purple, only slightly convex on the rounded side; first glume acute or obtuse; second glume
short-awned; sterile lemma empty, the awn as much as 5 cm. long; fruit elliptic, about 5 mm.
long including the point about 1 mm. long.

TYPE LocALIty: Zinapécuaro, Michoacan, Mexico.
DISTRIBUTION: Central Mexico to Guatemala.

4. Echinochloa colonum (L.) Link, Hort. Berol. 2: 209. 1833.

Panicum colonum L,. Syst. Nat. ed. 10. 870. 1759.

Panicum zonale Guss. Fl. Sic. Prodr. 1:62. 1827.

Oplismenus repens Presl, Rel. Haenk. 1: 321. 1830.

Panicum prorepens Steud. Syn. Gram. 46. 1854.

Panicum colonum zonale 1,. Dewey, Contr. U.S. Nat. Herb. 2: 502. 1894.

Echinochloa colona zonalis Wooton & Standley, N. Mex. Coll. Agr. Bull. 81:45. 1912,

Plants annual; stems prostrate-spreading, ascending, or erect, usually 2-4 dm. long, gla-
brous, compressed; leaf-sheaths glabrous, compressed; ligule wanting; blades rather lax, 5-10
em. long, rarely longer, 3-6 mm. wide, somewhat scabrous on the margin, occasionally bearing
transverse purple bands (zonate); panicle 5—10 or even 15 cm. long, the axis smooth or slightly
scabrous; racemes several, 1-2 cm. long, appressed or ascending, single or occasionally two,
approximate, the lower usually distant as much as 1 cm., the rachis triangular-flattened,
scabrous; spikelets about 3 mm. long, crowded, nearly sessile, in about 4 rows, second glume
and sterile lemma short-pointed but not awned; fruit about 2.5 mm. long, short-pointed.

TYPE LOCALITY: Jamaica. J

DistriBuTion: Tropical regions of the Old World; introduced in America; New Jersey to Florida,
and ag eehece to Missouri, Texas, and southern California; Oregon; Mexico and the West Indies to
Sou merica.

ILLUSTRATIONS: Trin. Ic. pl. 160; Duthie, Ill. Grasses Ind. pl. 4; Bull. U.S. eet Agr. Agrost. 7:
jf. 69; Britt. & Brown, Ill. Fl. ed. 2. f. 309; Contr. U.S. Nat. Herb. 22: 151. f. 3

5. Echinochloa paludigena Wiegand, Rhodora 23: 64. 1921.
Echinochloa paludigena soluta Wiegand, Rhodora 23: 64. 1921.

Stems mostly solitary, erect, rather stout, usually 1-1.5 meters tall; ligule none; panicles
narrow, usually 20-30 cm. long; racemes ascending, usually simple, rather evenly distributed
on the axis, not closely crowded, sometimes remote; spikelets about as in Z. Crusgalli but not
tuberculate; sterile floret staminate.

Type LOcALIry: Hillsborough County, Florida.
FI DistrisuTion: Ditches, marshes and wet places, often in shallow water, southern and central
orida.

312 NORTH AMERICAN FLORA [VoLuME 17

6. Echinochloa Crusgalli (L.) Beauv. Agrost. 53, 161. 1812.

Panicum Crusgalli L.. Sp. Pl. 56. 1753.

Panicum Cruscorvi .. Syst. Nat. ed. 10.870. 1759.

Milium Crusgalli Moench, Meth. 202. 1794.

Panicum grossum Salisb. Prodr. 18. 1796.

Panicum muricatum Michx. Fl. Bor. Am. 1:47. 1803. Not P. muricatum Retz. 1786.
Panicum Crusgalli aristatum Pursh, Fl. Am. Sept. 66. 1814.

Panicum Crusgalli mite Pursh, Fl. Am. Sept. 66. 1814.

Panicum Crusgalli purpureum Pursh, Fl. Am. Sept. 66. 1814.

Oplismenus zelayensis H.B.K. Nov. Gen. & Sp. 1: 108. 1815.

Panicum pungens Poir. in Lam. Encyc. Suppl. 4: 273. 1816.

Panicum Crusgalli muticum Ell. Bot. S.C. & Ga. 1: 114. 1816.

Setaria muricala R. & S. Syst. 2: 495. 1817.

Panicum frumentaceum Roxb. Fl. Ind. 1: 307. 1820. Not P. frumentaceum Salisb. 1796.
Echinochloa Crusgalli aristata S. F. Gray, Nat. Arr. Brit. Pl. 2: 158. 1821.
Oplismenus Crusgalli Dumort. Obs. Gram. 138. 1823.

Echinochloa zelayensis Schultes, in R. & S. Syst. Veg. Mant. 2: 269. 1824.
Orthopogon Crusgalli Spreng. Syst. 1: 307. 1825.

Echinochloa frumentacea Vink, Hort. Berol. 1: 204. 1827.

Oplismenus muricatus Kunth, Rév. Gram. 1: 44. 1829.

Oplismenus frumentaceus Kunth, Réy. Gram. 1:45. 1829.

Echinochloa Crusgalli mitis Peterm. Fl. Lips. 82. 1838.

Panicum zelayense Steud. Nom, Bot. ed. 2.2: 265. 1841.

Echinochloa Crusgalli mutica K. Koch, Linnaea 21: 436. 1848.

Panicum scindens Nees; Steud. Syn. Gram. 47. 1854.

Echinochloa Crusgalli frumentacea W. Wight, Cent. Dict. Suppl. 810. 1909.
Echinochloa muricata Fernald, Rhodora 17: 106. 1915.

Echinochloa Crusgalli edulis Hitche. Bull. U. S. Dep. Agr. 772: 238. 1920.
Echinochloa Crusgalli zelayensis Hitche. Bull. U. S. Dep. Agr. 772: 238. 1920.

Plants annual; stems erect or sometimes decumbent at base, as much as | m. or even 1.5
m. tall, glabrous; leaf-sheaths glabrous; ligule wanting, the ligular area sometimes slightly
pubescent; blades 5-15 mm. wide, scabrous on the margin, sometimes on the upper surface;
panicles erect or the larger ones nodding, 10-20 cm. long, the axis scabrous; racemes spreading,
ascending or appressed, the lower somewhat distant, as much as 10 cm. long, sometimes
branched, the upper approximate, shorter, the rachis scabrous, hispid, especially at the base;
spikelets crowded, about 3 mm. long, excluding the awns, strongly hispid or papillose-hispid
on the nerves, hispidulous on the internerves; sterile lemma with a well-developed palea, neuter,
the awn variable in length, mostly 5 to 10 mm. long on at least a part of the spikelets, sometimes
as much as 3 cm. long; fruit elliptic, turgid, narrowed into a cusp or point, 2.5-3 mm. long,
whitish or brownish.

‘TYPE LOCALITY: Europe. wk

DIstRIBUTION: Warm and temperate regions of both hemispheres; throughout North America
as far north as Maine and British Columbia, native and introduced.

ILLUSTRATIONS: Trin. Ic. pl. 161, 162, 164; Host, Gram. Austr. 2: pl. 19; J. M. Wood, Natal Pl.
pl. 151; Duthie, Ill. Grasses Ind. pl. 5; Vasey, Agr. Grasses U.S. pl. 11; ed. 2. pl. 14; Bull. U.S.
Dep. Agr. Agrost. 7: f. 70; Britt. & Brown, Ill. Fl. f. 243; ed. 2. f. 308; Contr. U.S. Nat. Herb. 22:
141. f. 30; 145. f. 31; 146. f. 32; 147. f. 33.

Note: The common form of E. Crusgalli, including E. muricata, is common throughout eastern
and northern United States. This may be awned or nearly awnless. On the Mexican plateau the
common form is E. celayensis, with ascending or appressed racemes of nearly awnless spikelets. This
form extends into the southwestern United States and grades into the eastern form. Echinochloa
Crusgalli mitis is the awnless form of FE. Crusgalli and is found throughout the range of this species.

Echinochloa Crusgalli edulis Hitche. (E. frumentacea Link), the Japanese barnyard millet, is a
cultivated form with thick, appressed, often falcate racemes and nearly awnless spikelets.

7. Echinochloa Crus-pavonis (H.B.K.) Schultes, in R. & S. Syst.
Veg. Mant. 2: 269. 1824.

Oplismenus Crus-pavonis H.B.K. Nov. Gen. & Sp. 1: 108. 1815.
Panicum sabulicola Nees, Agrost. Bras. 258. 1829.

Panicum Crus-pavonis Nees, Agrost. Bras. 259. 1829.

Echinochloa composita Presl; Nees, Agrost. Bras. 259, as synonym. 1830.
Panicum aristatum Mactad. Bot. Misc. 2: 115. 1831.

Oplismenus jamaicensis Kunth, Enum. Pl. 1: 147. 1833.

Panicum jamaicense Steud. Nom. Bot. ed. 2. 2: 257. 1841.

Panicum Crusgalli sabulicola D6ll, in Mart. Fl. Bras. 22: 142. 1877.
Oplismenus angustifolius Fourn. Mex. Pl. Gram. 40. 1886.

Echinochloa sabulicola Hitche. Contr. U. S. Nat. Herb. 17: 257. 1913.

ee

Part 4, 1931] POACEAE 313

Differs from E. Crusgalli in the soft nodding panicles usually tinged with pink or purple;
spikelets averaging smaller, usually about 2.5 mm. long, excluding the awn, more or less hispid
but not tuberculate; awn usually not more than | cm. long.

TYPE LOCALITY: Province of Cumana, Venezuela.

DISTRIBUTION: Southern Texas and West Indies to Bolivia and Argentina; also in tropical Africa.
Iniustrations: Trin. Ic. pl. 163; Contr. U.S. Nat. Herb. 22: 149. f. 34.

8. Echinochloa Walteri (Pursh) A. Heller, Cat. N. Am.
Piveda 2h I L900:

Panicum hirtellum Walt. F!. Car. 72. 1788. Not P. hirtellum L. 1759.

Panicum Walteri Pursh, Fl. Am. Sept. 66. 1814.

Panicum Crusgalli hispidum Ell. Bot. S. C. & Ga. 1: 114. 1816.

Panicum hispidum Muhl. Deser. Gram. 107. 1817. Not P. hispidum Forst. 1786.
Panicum longisetum Torr. Am. Jour. Sci. 4:58. 1822. Not P. longisetum Poir. 1816.
Orthopogon hispidus Spreng. Syst. 1: 307. 1825.

Oplismenus longisetus Kunth, Rév. Gram. 1:45. 1829.

Echinochlca longiaristata Nash, in Small, Fl. SE. U.S. 84. 1903.

Plants annual; stems erect, often succulent, often rooting at the lower nodes when growing
in mud or water, 1-2 m. high, as much as 2.5 cm. thick at base, glabrous; leaf-sheaths papillose-
hispid, or papillose only, or sometimes scabrous only, or rarely glabrous, sometimes only the
lower sheaths hispid or the hairs confined to the marginal region, the collar more or less
pubescent; ligule wanting, the ligular area often pubescent; blades usually 10-15 mm. wide,
sometimes as much as 3 cm. wide; mostly scabrous on both surfaces; panicle large and dense,
as much as 3 dm. long, erect or nodding, the axis very scabrous, more or less papillose-hispid
on the angles; racemes appressed or ascending, single or, in the larger plants, usually fascicled,
approximate or the lower somewhat distant, sometimes branched, as much as 10 em. long,
the rachis hispidulous and more or less papillose-hispid, especially at base; spikelets closely
arranged, several on short branches of the raceme, mostly long-awned, often purple, about
3 mm. long; sterile floret with a palea, neuter, the awn usually 1-2 cm. long, sometimes longer,
more rarely reduced to a short point; fruit about 3 mm. long, fusiform, about 1 mm. wide,
narrower and more fusiform than in E. crusgallz.

TYPE LocALITy: South Carolina.

DISTRIBUTION: Massachusetts to Florida, and westward to Wisconsin and Texas; Cuba.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: 138. f. 29.

9. Echinochloa oplismenoides (Fourn.) Hitche. Contr. U. S. Nat.
Herb. 22: 136. 1920.
Berchtoldia oplismenoides Fourn. Mex. Pl. Gram. 41. 1886.

Plants annual; stems erect, as much as | m. tall, glabrous, the nodes glabrous or rarely
appressed-hispidulous; leaf-sheaths glabrous; ligule wanting, rarely a line of short hairs; blades
mostly less than 1 cm. wide, scaberulous on the margin and upper surface; panicle narrow,
usually not more than 15 cm. long, the axis angled, scabrous; racemes appressed, the lower mostly
3-6 cm. long, the rachis angled, scabrous and more or less stiffly pilose, not hispid at base;
spikelets rather densely set, 4-5 mm. long; first glume acutish, glabrous; second glume
hispidulous on the nerves, acuminate; sterile lemma empty or with palea only, the awn usually
about I cm. long, rarely as much as 3 cm. long; fruit about 4 mm. long, mucronate.

Type Locatity: Toluca, Mexico.
DISTRIBUTION: Mexico, 1 and Sonora to Be take and Puebla.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: 136. f. 27

66. CHAETIUM Nees, Agrost. Bras. 269. 1829.
Berchtoldia Presl, Rel. Haenk. 1: 323. 1830.

Perennial grasses with long narrow leaf-blades and dense narrow panicles. Spikelets
short-pedicelled, dorsally compressed, lanceolate, having a long slender callus-like base made up
of the elongated joint of the rachilla between the glumes, the bearded base of the first glume
adnate to it. Glumes bearing awns 3 to 4 times the length of the body of the spikelet, the
first reduced’ to the awn or, in C. bromoides, the pair broadened and inclosing the rest of the

314 NORTH AMERICAN FLORA [VOLUME 17

spikelet. Sterile lemma bearing a shorter awn or awn-tipped only, the sterile palea obsolete.
Fruit subindurate, lanceolate, the lemma acuminate into a scabrous awn or point, the thin
margins flat, the summit of the palea not inclosed.

Type species, Chaelium festucoides Nees.

First glume as broad as spikelet. 1. C. bromoides.
First glume setiform. 2. C. cubanum.

1. Chaetium bromoides (Presl) Benth.; Hemsl. Biol. Centr. Am.
Botnsn003e)) LS8or
Berchtoldia bromoides Presl, Rel. Haenk. 1: 324. 1830.
Panicum Berchtholdia Doll, in Mart. Fl. Bras. 2?: 150. 1877.

Stems erect, 0.5-1 m. tall, glabrous or the lower pubescent, the nodes appressed-hispidu-
lous, producing stout creeping leafy stolons from the base; leaf-sheaths glabrous or weakly his-
pid, hispid on the collar, densely velvety-hispid at the base on the stolons; ligule a dense line of
stiff hairs 1-2 mm. long; blades narrowed and folded below, flat above, 2-4 dm. long, 3-6 mm.
wide, rather sparsely pilose or hispidulous; panicle 1-2 dm. long, erect, the branches appressed,
the lower as much as 7 cm. long, the axis and rachises scabrous; spikelets fusiform, nearly
1 cm. long, including the 3 mm. long antrorsely hispid base, narrowed above into the awns of
the glumes, the first about 2 cm. long, the second shorter, the pedicels slender, stiff, scabrous,
disarticulating obliquely; glumes with about 3 nerves in the center and 1 or 2 nerves at each
margin; fruic about 5 mm. long, short-awned.

TYPE LOCALITY: Mexico.
DistrRiBuTION: Chihuahua to Costa Rica.
ILLUSTRATIONS: Presl, Rel. Haenk. pl. 43; Rep. Mo. Bot. Gard. 10: pl. 25.

2. Chaetium cubanum (Wright) Hitche. Contr. U.S. Nat.
Herb. 12: 232. 1909.

Perotis ? cubana C. Wright; Sauv. Anal. Acad. Ci. Habana 8: 288. 1871.

Stems erect, striate, about 4 dm. tall; leaf-blades linear, acuminate, convolute, sparsely
ciliate at base; panicle narrow, racemiform; spikelets about 6 mm. long, including the 2 mm.
long stipe, this hispid at the oblique base; first glume awn-like, about 2 cm. long; second glume
5-nerved, narrowed into an awn a little longer than that of the first glume; sterile lemma
about 4 mm. long, acute; fruit about 4 mm. long, narrowly elliptic, acute.

TYPE LOCALITY: Eastern Cuba.
DISTRIBUTION: Known only from the type collection.

67. TRICHOLAENA Schrad.; Schultes, in R. & S. Syst. Veg.
Mant. 2: 163. 1824.

Rhynchelytrum Nees; Lindl. Nat. Syst. ed. 2. 446. 1836.
Monachyron Parl. in Hook. Niger Fl. 190. 1849,

Annual or perennial grasses with rather open panicles of silky spikelets on short capillary
pedicels. First glume small, much shorter than the spikelets, silky. Second glume and
sterile lemma equal, raised on a stipe above the first glume, acute, emarginate or slightly lobed,
short-awned, covered except toward the apex with long silky hairs, the palea of the sterile
lemma well developed. Fertile lemma shortef than the spikelets, cartilaginous, smooth, boat-
shaped, obtuse, the margins thin, not inrolled, inclosing the margins of the palea.

Type species, Tricholaena micrantha Schrad.

1. Tricholaena rosea Nees, Cat. Sem. Hort. Vratisl. 1836;
Fl. Afr. Austr. 17. 1841.

Rhynchelytrum roseum Stapf & Hubbard (Bews, World’s Grasses 223; hyponym. 1929); Prain, Fl.
Trop. Afr.9:680. 1930. (Stapf & Hubbard restrict Tricholaena to T. Teneriffae and its allies.)

Plants annual or perennial; stems erect, or decumbent and often rooting at the base,
glabrous or pubescent, or papillose-pubescent, the nodes often pubescent; leaf-sheaths sparsely

Part 4, 1931] POACEAE 315

papillose-pubescent, striate; ligule a dense row of stiff hairs about 1 mm. long or a little less;
blades flat, mostly less than 15 cm. long, 3-7 mm. wide, slightly scabrous on the margin and
upper surface; panicle 1-2 dm. long, the axis scaberulous or smooth, the branches slender,
ascending, branched at base; pedicels capillary, flexuous or S-shaped, bearing near the summit
several hairs 2-4 mm. long; spikelets tawny or often a beautiful claret, very silky, the hairs
4-6 mm. long, appressed, often forming two groups to correspond to the second glume and
sterile lemma; first glume narrow, about 1 mm. long, silky; second glume and sterile lemma
equal, about 4 mm. long, somewhat abruptly narrowed above the middle into a narrow
emarginate tip, the lower part silky, the tip free of hairs but ciliate, the awn 1-2 mm. long;
fruit smooth, about 2 mm. long, obtuse.

TYPE LocaALIty: South Africa.

DIstRIBuTION: Tropical Africa; introduced in America; cultivated in Florida as a forage grass
(Natal grass); Florida; Guatemala; Cuba; also in South America and the Hawaiian Islands.

ILLUSTRATIONS: J. M. Wood, ‘Natal Pl. pl. 180; Bull. U.S. Dep. Agr. 772: f. 147.

68. SETARIOPSIS Scribn.; Millsp. Field Mus. Publ. Bot. 1:
288. 1896.

Annual grasses with erect stems, flat leaf-blades, and narrow panicles. Spikelets elliptic,
plano-convex, similar in structure to those of Panicum, arranged in clusters on the short
branches of a narrow or spike-like panicle, each pedicel bearing a slender bristle (modified
branchlet) longer than the spikelet. First glume much shorter than the spikelet, broadly
ovate, several-nerved. Second glume and sterile lemma about equal, several-nerved, the
glume broad, cordate or auriculate at base, the lemma narrower, somewhat lyre-shaped,
including a palea but no stamens. Fertile lemma apiculate, somewhat coriaceous but scarcely
indurate, transversely rugose or nearly smooth. Palea inclosed by the inrolled margins of
the lemma to the tip or nearly to the tip, of the same texture and markings as the lemma.

Type species, Setaria latiglumis Vasey.

Sheaths hispid; second glume conspicuously widened; fertile lemma nearly
1. S. latiglumis.

smooth.
Sheaths glabrous; second glume not conspicuously widened; fertile lemma trans-
versely rugose. 2. S. auriculata.

Setariopsis latiglumis (Vasey) Scribn.; Millsp. Field Mus.
Publ. Bot. 1: 289. 1896.

Setaria latiglumis Vasey, Bull. Torrey Club 13: 229. 1886.

Annual; stems erect or rarely somewhat geniculate at base, slender, scabrous, hispid at
the nodes, as much as | meter tall; leaf-sheaths papillose-hispid; ligule a densely ciliate short
membrane, the hairs 1-2 mm. long; blades flat, scabrous, hispid around the narrowed base,
acuminate, as much as 30 cm. long and 15 mm. wide, panicles as much as 25 em. long, narrow,
rather loose in large specimens, spike-like and interrupted in the small ones, the axis scabrous,
often sparsely or densely villous, the branches appressed or ascending, the lower in the large
panicles being as much as 5 cm. long and compound; spikelets glabrous, ovate, gibbous on
the convex side, about 4 mm. long, closely arranged along the branches or branchlets, the
pedicels 1-3 mm. long, the subtending bristles slender, somewhat flexuous, 1-2 cm. long;
first glume 1.5 mm. long, 2 mm. wide, about 7-nerved; second glume cordate (when spread
out), 3.5 mm. long, 4 mm. wide, many-nerved, the nerves somewhat anastomosing, the margins
serrate, especially toward the base; sterile lemma narrower than the second glume, about
3.5 mm. long, the lower part circular, about 1.5 mm. long, the upper part narrower, oblong,
about 1 mm. long, truncate or somewhat notched at apex, the several nerves parallel, the
main nerves reaching the apex without converging; fertile lemma somewhat coriaceous but
not indurate, ovate, apiculate, about 2.5 mm. long, obscurely transversely wrinkled.

Tyre Locatiry: Southwest Chihuahua, Mexico.

DIstRiBUTION: Pacific coast of Mexico from Chihuahua to Chiapas.
ILLUSTRATION: Field Mus. Publ. Bot. 1: pl. 11.

316 NORTH AMERICAN FLORA [VoLuME 17

2. Setariopsis auriculata (Fourn.) Scribn.; Millsp. Field Mus.
Publ. Bot. 1: 289. 1896.
Setaria auriculata Fourn. Mex. P!. Gram. 43. 1886.
Setariopsis Scribneri Mez, Notizbl. Bot. Gart. Berlin 7:58. 1917.

Annual; stems slender, glabrous except in the vicinity of the nodes, as much as | meter
tall; leaf-sheaths compressed, glabrous or nearly so, hispid on the collar; ligule a densely ciliate
membrane about 1 mm. long; blades flat, narrowed at the base, acuminate, scabrous, as much
as 15 cm. long and 1 cm. wide; panicles narrow, as much as 15 cm. long, the axis scabrous, more
or less villous, the branches ascending, the lower in large specimens as much as 2 cm. long, in
small specimens short, forming an interrupted spike-like panicle; spikelets glabrous, ovate,
about 3 mm. long, gibbous on the convex side, the pedicels very short, the subtending bristles
5-10 mm. long, somewhat flexuous; first glume broad-triangular, 1.5 mm. long, nearly 2 mm.
wide (when spread out), about 7-nerved; second glume 3 mm. long, ovate, auriculate near the
base, that is, with a small sinus on each side of the base, several-nerved; sterile lemma a little
longer than the second glume, oblong, concave on the back, the lower third hardened and
bulged-out on each side, the upper part inrolled around the fruit, about 7-nerved, the palea
narrow, about one third as long as the lemma; fertile lemma ovate, strongly convex, about
2 mm. long, 3-nerved, somewhat indurate, transversely rugose and roughened, the lemma
similar in texture, free at the apex.

TYPE LOCALITY: Campechy, Mexico.

DISTRIBUTION: Western and southern Mexico, Sonora to Oaxaca and Yucatan; also in Colombia.
ILLUSTRATION: Field Mus. Publ. Bot. 3: 39.

69. SETARIA Beauv. Agrost. 51. 1812. Not Setaria Achar.
1798; nor Setaria Michx. 1803.

Panicum § Ptychophyllum A. Br. Ind. Sem. Hort. Berol. 1855: App. 18. 1855.
Chaetochloa Scribn. Bull. U.S. Dep. Agr. Agrost. 4:38. 1897.

Annual or perennial grasses with flat or rarely involute leaf-blades, and narrow, usually
spike-like, or rarely open panicles. Spikelets lanceolate or elliptic, rarely globose, sessile or
short-pedicelled, single or in clusters, some or all subtended by one to several bristles (sterile
branchlets), deciduous, falling free from the bristles, awnless, the main branches usually short,
rarely elongate. First glume broad, usually less than half the length of the spikelet, 3- to 5-
nerved. Second glume and sterile lemma equal or the former shorter, several-nerved. Fertile
lemma coriaceous or indurate, smooth or usually rugose or cross-wrinkled.

Type species, Panicum viride 1.

Blades narrowly elliptic, plaited; bristles below only a part of the spikelets,
rarely below all. (Subgenus PryCHOPHYLLUM.)
Plants annual; blades usually less than 2 em. wide. 1. S. barbata.
Plants perennial; blades usually more than 3 em. wide.
Panicle of numerous approximate more or less 1-sided racemes, spikelet-
bearing to the base, 2—5 cm. long, rarely the lower much longer. 2. S. Poiretiana.
Panicle of more or less fascicled branches, not or scarcely 1-sided, some
of them elongate and naked at base.
Branches of panicle as much as 10 cm. long; bristles usually not more
than twice as long as the spikelets, inconspicuous; blades as much
as 6 cm. wide. 3. S. palmifolia
Branches of panicle slender, finally spreading, as much as 20 cm.
long; bristles as much as 15 mm. long; blades as much as 10 cm.
See wide: 4. S. paniculifera.
Blades linear-lanceolate to linear, narrow; bristles below all the spikelets.
(SETARIA proper.)
Bristles below each spikelet numerous, at least more than 5; panicle dense,
cylindric, spike-like.

Plants annual; spikelets 3 mm. long. 5. S. lutescens.
_Plants perennial; spikelets mostly 2—2.5 mm. long. 6. S. geniculata.
Bristles below each spikelet 1, or by the abortion of the spikelets, 2 or 3.
Bristles more or less retrorsely scabrous.
Plants perennial; spikelets globose or nearly so. 7. S. tenax.
Plants annual; spikelets not globose.
Spikelets about 2 mm. long. 8. S. verticillata.

Spikelets about 1.5 mm. long.
Panicle usually green, rarely as much as 8 cm. long, less than
5 mm. thick, the bristles 2-3 mm. long. 9. S. scandens.

Part 4, 1931] POACEAE 317

Panicle usually purple, as much as 15 cm. long and 1 cm.

thick, the bristles about 1 cm. long. 10. S. tenacissima.
Bristles antrorsely scabrous only.
Plants annual.
Fertile lemma at maturity finely cross-lined or nearly smooth.

Panicle loosely flowered, tapering above. 11. S. Grisebachii.

Panicle compactly flowered, sometimes interrupted at base.

Plants as much as 3 meters tall; bristles 1-2 cm. long;

fertile lemma smooth or nearly so. 12. S. magna.
Plants mostly less than | meter tall.
Axis of panicle scabrous but not villous. 13. S. ambigua.

Axis of panicle villous.
Panicle cylindric, tapering above, green; spikelet
falling entire. 14. S. viridis.
Panicle lobed or interrupted, often large and
heavy, purple or yellow; fruit deciduous from
glumes and sterile lemma. 15. S. italica.
Fertile lemma coarsely transversely rugose.
Axis of panicle thickly clothed with white stiff hairs 2 mm.

long. 16. S. longipila.
Axis of panicle villous, the hairs about 1 mm. long.
Panicie densely flowered, cylindric; sheaths scabrous. 17. S. corrugata.
Panicle loosely flowered.
Blades scabrous but not hispid. 18. S. Liebmanni.
Blades sparsely hispid. 19. S. latifolia.
Plants perennial.
Spikelets 3 mm. long.
Blades scabrous. 20. S. macrosperma,
Blades villous. 21. S. villosissima.

Spikelets 2-2.5 mm. long.
Panicle attenuate at apex.
Blades linear-lanceolate, more than 5 mm. broad; panicle
interrupted or branched, the branches | to 3 cm. long. 22. S. setosa.
Blades slender, mostly Jess than 5 mm. broad; panicle
slender, very narrow. 23. S. rariflora.
Panicle often narrowed toward the summit but not attenuate.
Branches of primary panicle stiffly ascending, of about
equal length except toward the summit; panicle yellow-
ish or brownish, the bristles 1-2 cm. long. 24. S. vulpiseta.
Branches of panicle short or only the lower as much as
2-3 em. long; panicle pale or greenish, the bristles
irregular in length, the longer sometimes I—1.5 cm.
long.
Blades mostly less than 1 cm. wide, often folded;
panicle usually loosely or interruptedly spike-like,
the branches usually not more than | cm. long. 25. S. macrostachya.
Blades flat, as much as 1.5 cm. wide; panicle tapering
from near the base, the lower branches as much as
3 cm. long. 26. S. Scheelet.

1. Setaria barbata (Lam.) Kunth, Rév. Gram. 47. 1829.

Panicum barbatum Lam. Tabl. Encye. 1: 171. 1791.

Panicum costatum Roxb. F1. Ind. 1: 314. 1820.

Panicum viaticum Salzm.; Doll, in Mart. Fl. Bras. 22: 155. 1877.
Chamaeraphis viatica Kuntze, Rev. Gen. 770, 1891.

Chamaeraphis costata Kuntze, Rev. Gen. 771. 1891.

Chaetochloa baxbata Hitche. & Chase, Contr. U. S. Nat. Herb. 18: 348. 1917.

Annual; stems decumbent, spreading, often rooting at the lower nodes, branching, glabrous,
scabrous or villous near the pubescent nodes, as much as 2 meters long, but often much less;
leaf-sheaths compressed, ciliate, glabrous or papillose-hispid; ligule about 1 mm. long, densely
ciliate, blades narrowly elliptic, flat and rather thin, narrowed to a somewhat truncate base in
the upper leaves, to a petiole-like base in the lower, as much as 30 cm. long and 2.5. cm. wide,
distinctly plicate in large specimens, obscurely so in dwarf ones; panicles long-exserted, green,
as much as 20 em. long, the rachis scabrous and villous, the branches ascending or spreading,
as much as 4 cm. long; spikelets oblong-elliptic, glabrous, about 2.5 mm. long, tending to be
in two rows along the branches, at least along the upper part, o!ten clustered on branchlets on
the lower part of the branches, the pedicels very short, the bristles flexuous, 5-10 mm. long,
subtending a part of the spikelets but usually rather numerous; first glume circular, 3-nerved,
1 mm: long; second glume about two-thirds as long as the fertile lemma, ovate, acute, 7-nerved;
sterile lemma as long as the fertile, acute, 7-nerved, the palea about as long and wide as the

318 NORTH AMERICAN FLORA [VOLUME 17

lemma; fertile lemma elliptic, acute, a little over 2 mm. long, strongly transverse-rugose, the
palea inclosed to the tip.

Type LocaLity: Mauritius.

DISTRIBUTION: Tropics of Asia; introduced from Florida and the West Indies to Brazil.

ILLUSTRATION: Contr. U. S. Nat. Herb. 22: 159. f. 36.

Nore: Setaria barbata is described by Grisebach (Fl. Brit. W. Ind. 547. 1864) and J. D.
Hooker (FI. Brit. Ind. 7:56. 1896) under Panicum flavescens Sw.

2. Setaria Poiretiana (Schultes) Kunth, Rév. Gram. 47. 1829.

Panicum elongatum Poir. in Lam. Encye. Suppl. 4: 278. 1816. Not P. elongatum Salisb. 1796; nor

P. elongatum Pursh, 1814.

Panicum sulcatum Bertol. Excerpta 14. 1820. Not P. sulcatum Aubl. 1775.
Selaria sulcata Raddi, Agrost. Bras. 50. 1823.

Panicum Poiretianum Schultes, in R. & S. Syst. Veg. Mant. 2: 229. 1824.
Panicum speciosum Nees; Trin. Gram. Pan. 169. 1826.

Panicum Crus-ardeae Willd.; Nees, Agrost. Bras. 253. 1829.

Setaria Crus-ardeae Kunth, Réy. Gram. Suppl. xii. 1830.

Panicum flabellatum Steud. Syn. Gram. 53. 1854.

Agrostis flabellata Salzm.; Steud. Syn. Gram. 53, as synonym. 1854.

Setaria Jurgensenii Fourn. Mex. Pl. Gram. 42. 1886.

Chamaeraphis Crus-ardeae Kuntze, Rev. Gen. 770. 1891.

Chamaeraphis speciosa Kuntze, Rev. Gen. 770. 1891.

Chamaeraphis ‘‘ Juergensii”’ [Jurgensenii] Kuntze, Rev. Gen. 770. 1891.
Panicum Jurgensenii Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21: 40. 1900.
Chaetochloa sulcata Hitche. Contr. U.S. Nat. Herb. 17: 260. 1913.

Cespitose perennial; stems erect, 1-1.5 meters tall, glabrous, or villous in the vicinity
of the nodes; leaf-sheaths papillose-hispid, mostly longer than the internodes, the uppermost
elongate, scabrous; ligule ciliate, about 2 mm. long; blades strongly plicate, scaberulous,
sometimes sparsely hispid, flat, as much as 1 meter long and 10 cm. wide, narrowed toward
each end, the base resembling a petiole; panicles erect, rather compact, commonly purple,
long-exserted, as much as 60 cm. long, and 10 cm. wide, the axis puberulent, the branches
ascending, irregularly clustered, approximate, usually somewhat falcate, the lower usually
3-5 cm. but sometimes as much as 10 cm. or the distant lowermost even longer; spikelets
secund on the branches, narrowed, ellipsoidal, about 3 mm. long, the pedicels puberulent,
usually very short, some or all on each branch subtended by somewhat flexuous bristles 5-10
mm. long; first glume 1.5 mm. long, oval, obtuse, 5-nerved; second glume similar to the first,
2 mm. long, 5-nerved; sterile lemma oblong-ovate, acutish, 3 mm. long, obscurely 5-nerved,
the palea wanting; fertile lemma somewhat coriaceous, ellipsoidal, apiculate, 3 mm. long,
very obscurely cross-wrinkled; palea similar to the lemma in texture and marking, the apex free.

TYPE Locality: Brazil.

DISTRIBUTION: San Luis Potosi to Brazil and Paraguay.
ILLUSTRATIONS: Mart. Fl. Bras. 2?: pl. 26; Contr. U. S. Nat. Herb. 22: 160. f. 37.

3. Setaria palmifolia (Willd.) Stapf, Jour. Linn. Soe. 42:
186. 1914.
Panicum plicatum Willd. Enum. 1033. 1809. Not P. plicatum Lam. 1791.
Panicum palmifolium Willd.; Poir. in Lam. Encyc. Suppl. 4: 282. 1816.
Panicum plicatum haitiense Kunth; Griseb. Fl. Brit. W. Ind. 547, as synonym. 1864.

Chamaeraphis palmifclia Kuntze, Rev. Gen. 771. 1891.
Chaetochloa palmifolia Hitche. & Chase, Contr. U. S. Nat. Herb. 18: 348. 1917.

Perennial; stems I-1.5 meters tall, glabrous or sparsely villous, the nodes puberulent;
leaf-sheaths papillose-hispid or glabrate, hispid on the collar; ligule densely ciliate, about
2 mm. long; blades strongly plicate, flat, pubescent or glabrate, elliptic, narrowed to a petiole-
like base, as much as 50 cm. long and 6 cm. wide; panicles rather loose and open, green, long-
exserted, as much as 40 cm. long, the rachis scabrous, the branches ascending or spreading,
scattered, somewhat distant, especially below, 5-10 cm. long, compound; spikelets lanceo-
late, acute, about 3 mm. long, closely arranged on short branchlets appressed along the main
branches, forming interrupted compound racemes, the pedicels very short, the bristles incon-
spicuous, at the ends of the branchlets and subtending a part of the spikelets, usually not more
than twice as long as the spikelets, often short and imperfectly developed; first glume 1 mm.
loug, obtuse, 5-nerved; second glume 7-nerved, the outer pair obscure, acutish, 1.5 mm, long;

Part 4, 1931] POACEAE 319

sterile lemma 5-nerved, acute, 3 mm. long, the palea narrow, about half as long as the lemma;
fertile lemma lanceolate, acute, somewhat apiculate, 2.5 mm. long, obscurely cross-wrinkled,
the palea entirely included in the margins of the lemma.

TYPE LOCALITY: India.
DisTRIBUTION: Tropics of the Eastern Hemisphere; introduced in Jamaica.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: 162. f. 38.

4. Setaria paniculifera (Steud.) Fourn.; Hemsl. Biol. Centr. Am.
Bota oa 0on el ooo:

Panicum sulcatum Aubl. Pl. Guian. 50. 1775.

Panicum paniculiferum Steud. Syn. Gram. 54. 1854.

Setaria effusa Fourn. Mex. Pl. Gram. 42. 1886.

Chamaeraphis effusa Kuntze, Rev. Gen. 770. 1891.

Chamaeraphis paniculifera Kuntze, Rev. Gen. 770. 1891.

Chamaeraphis sulcaia Kuntze, Rev. Gen. 770. 1891.

Panicum mexicanum Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:40. 1900.
Chaetochloa sulcata Hitche. Contr. U.S. Nat. Herb. 17: 260. 1913.

Setaria sulcata A. Camus, Bull. Mus. Paris 30: 108. 1924. Not S. sulcala Raddi, 1823,

Perennial; stems robust, as much as 4 meters tall, glabrous, the nodes glabrous; leaf-
sheaths papillose-hispid all over or only at the margin, hispid on the collar; ligule a ciliate
membrane 1—2 mm. long; blades flat, strongly plicate, somewhat scabrous, as much as | meter
long and 10 cm. wide at the middle, tapering toward each end, the lower into a long petiole-
like base; panicles green or purplish, often very large, as much as 70 cm. long, the branches
ascending, finally spreading, as much as 20 cm. long, these branching and rebranching, the
whole panicle becoming loose and open, the axis somewhat scabrous; the branches very
scabrous-pubescent; spikelets usually loosely arranged, elliptic-lanceolate, about 3 mm. long,
obscurely nerved, glabrous, the pedicels 0.5-2 mm. long, scabrous-pubescent, the flexuous
bristles as much as 15 mm. long, subtending a part of the spikelets; first glume nearly half as
long as the spikelet, obtuse, 3-5-nerved; second glume about two thirds as long as spikelet,
acutish, 5-7-nerved; sterile lemma about as long as the fertile, acute, 5-nerved, the palea
narrow, shorter than the lemma; fertile lemma acute, slightly apiculate, closely but distinctly.
transverse-rugose, the palea inclosed to the tip.

TYPE LOCALITY: Oaxaca, Mexico.
DIstTRIBUTION: Southern Mexico and Guadeloupe to Venezuela and Ecuador.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: 164. f. 39.

5. Setaria lutescens (Weigel) Hubbard, Rhodora 18: 232. 1916.

Panicum lutescens Weigel, Obs. Bot. 20. 1772.

Panicum glaucum flavescens Ell. Bot. S.C. & Ga. 1: 113. 1816.

Panicum compressum Balb.; Steud. Nom. Bot. ed. 2. 2: 254, assynonym. 1841.
Chaetochloa lutescens Stuntz, Inv. U.S. Dep. Agr. 31: 36, 86. 1914.

Plants annual, erect, often much-branched at base, the stems becoming geniculate below,
or in open ground spreading or even prostrate-spreading; stems rather succulent below, as
much as | meter tall or in rich soil even taller, compressed below, smooth, scabrous just below
panicle; leaf-sheaths smooth, compressed-keeled; ligule a ciliate membrane about 1 mm. long;
blades as much as 25 em. long and 1 cm. wide, flat, twisted in a loose spiral, the upper surface
along the upper half facing downward, acuminate-pointed, often glaucous, scabrous on the
upper surface, toward the base beset with long lax hairs, glabrous beneath; panicle dense,
evenly cylindric, spike-like, yellow at maturity, mostly 5-10 cm. long, sometimes longer,
about 1 em. thick, rounded at the summit, sometimes slightly interrupted at the base, the axis
densely pubescent; branches very short, mostly less than 1 mm. long, pubescent like the axis,
each branch bearing one developed spikelet and below this a cluster of short branchlets ending
in bristles, sometimes a second small and undeveloped spikelet borne in one of these secondary
clusters; branchlets irregular in length, mostly less than 1 mm. long, bearing 1 to several
bristles, the whole cluster on each branch being usually more than 5 and sometimes more than
20; bristles antrorsely scabrous, yellow, irregular in length, the longer ones 2-3 times as
long as the spikelet; spikelets about 3 mm. long, flat on one side, strongly convex on the other,
oval in outline but slightly narrowed toward the apex; first glume ovate, about half as long as
spikelet, pale, with 3 strong green nerves and an outer inconspicuous pair; second glume about

320 NORTH AMERICAN FLORA [VOLUME 17

two thirds as long as the spikelet, with 5 strong nerves and 1 or 2 additional weaker pairs;
sterile lemma about as long as the spikelet, 5-nerved, the base embracing the edges of the fertile
lemma for about half way, containing a well-developed palea but no stamens; fertile floret
strongly marked with numerous transverse ridges.

TYPE LOCALITY: Pomerania, Germany.

DISTRIBUTION: Maine to Florida, and westward to South Dakota and New Mexico; Oregon
and California; Jamaica. Introduced from Europe; temperate regions, rare in the Tropics.

ILLUSTRATIONS: Vasey, Agr. Grasses U. S. 18; ed. 2. 20; Trin. Ic. pl. 195; Reichenb. Ic. Fl.
Germ. 1: pl. 47, no. 1466; Schreb. Beschr. Gras. pl. 25; Host, Gram. Austr. 2: pl. 16; Bull. U.S.
Dep. Agr. Agrost. 17: f. 401; Hitchc. Text-book Grasses f. 23; Britt. & Brown, Ill. Fl. f. 281; ed. 2.
f. 391; Contr. U. S. Nat. Herb. 22: 167. f. 40; Bull. U. S. Dep. Agr. 772: f. 148.

Nore: The name formerly applied to this species is Setaria glauca Beauy., based on Panicum
glaucum 1,., which name should be applied to the species known as Pennisetum typhoideum Rich. (P.
americanum (1,.) K. Schumann; Penicillaria spicata Willd.). The following synonyms are based on
Panicum glaucum L,. as to name but refer to Selaria lutescens as to plant:

Pennisetum glaucum R. Br. Prodr. 195. 1810.

Setaria glauca Beauv. Agrost. 51, 178. 1812.

Chamaeraphis glauca Kuntze, Rev. Gen. 767. 1891.

Ixophorus glaucus Nash, Bull. Torrey Club 22: 423. 1895.

Chaetochloa glauca Scribn. Bull. U.S. Dep. Agr. Agrost. 4: 39. 1897.

6. Setaria geniculata (lam.) Beauv. Agrost. 51,178. 1812.

Panicum geniculatum Lam. Encyc. 4: 727 (err. typ. 737). 1798.

Cenchrus parviflorus Poir. in Lam. Encyc. 6: 52. 304.

Pennisetum geniculatum Jacq. f. Eclog. Gram. pl. 26. 1815.

Setaria gracilis H.B.K. Nov. Gen. & Sp. 1: 109. 1815.

Selaria purpurascens H.B.K. Noy. Gen. & Sp. 1: 110. 1815.

Panicum imberbe Poir. in Lam. Encyc. Suppl. 4: 272. 1816.

2?Panicum pumilum Poir. in Lam. Encyc. Suppl. 4: 273. 1816.

Panicum laevigatum Muhl.; Ell. Bot. S. C. & Ga. 1: 112. 1816.

Panicum glaucum purpurascens Ell. Bot. S. C. & Ga. 1:113. 1816.

Setaria imberbis R. & S. Syst. Veg. 2: 891. 1817.

Pennisetum laevigatum Nutt. Gen. 1:55. 1818.

Setaria laevigata Schultes, in R. & S. Syst. Veg. Mant. 2: 275. 1824.

Setaria affinis Schultes, in R. & S. Syst. Veg. Mant. 2: 276. 1824.

Setaria berteroniana Schultes, in R. & S. Syst. Veg. Mant. 2: 276. 1824.

Panicum flavum Nees, Agrost. Bras. 238. 1829.

Panicum imberbe pumilum Nees, Agrost. Bras. 240. 1829.

Panicum fuscescens Willd.; Nees, Agrost. Bras. 241, as synonym. 1829.

Panicum dasyurum Nees, Agrost. Bras. 241. 1829.

Panicum penicillatum Willd.; Nees, Agrost. Bras. 242. 1829. Not P. penicillatum Nees, Agrost.

Bras. 145. 1829.

Panicum tejucense Nees, Agrost. Bras. 243. 1829.

Setaria flava Kunth, Rév. Gram. 46. 1829.

Setaria Ventenatii Kunth, Rév. Gram. 251. 1830.

Selaria tejucensis Kunth, Rév. Gram. Suppl. xi. 1830.

Selaria penicillata Presl, Rel. Haenk. 1: 314. 1830.

Panicum Ventenatii Steud. Nom. Bot. ed. 2. 2: 265. 1841.

Panicum Berleronianum Steud. Syn. Gram. 50. 1854.

Panicum psilocaulum Steud. Syn. Gram. 50. 1854.

Setaria glauca laevigata Chapm. Fl. S. U.S. 578. 1860.

Setaria glauca imberbis Griseb. F1. Brit. W. Ind. 554. 1864.

Setaria glauca penicillata Griseb. Fl. Brit. W. Ind. 554. 1864.

Panicum imberbe purpurascens Doll, in Mart. Fl. Bras. 22: 157. 1877.

» Panicum imberbe latifolium DOll, in Mart. Fl. Bras. 22: 157. 1877.
~ Panicum virescens Salzm.; Doll, in Mart. Fl. Bras. 2?: 157, as synonym. 1877.
~ Panicum glaucescens Salzm.; D6ll, in Mart. Fl. Bras. 2: 157, as synonym. 1877.

Panicum imberbe dasyurum Doll, in Mart. Fl. Bras. 22: 157. 1877.

Setaria streplobotrys Fourn. Mex. Pl. Gram. 47. 1886.

Chamaeraphis glauca penicillata Kuntze, Rev. Gen. 767. 1891.

Chamaeraphis glauca imberbis Kuntze, Rev. Gen. 767. 1891.

Setaria perennis Hall; Smyth, Check-list Pl. Kans. 26. 1892; Trans. Kansas Acad. 13: 102. 1893.
‘ Setaria gracilis purpurascens Arech. Anal. Mus. Nac. Montevideo 1: 164. 1894.
* Setaria gracilis latifolia Arech. Anal. Mus. Nac. Montevideo 1: 165. 1894.
“Selaria gracilis dasyura Arech. Anal. Mus. Nac. Montevideo 1: 165. 1894.

» Chamaeraphis Ventenatii Beal, Grasses N. Am. 2: 153. 1896.

Chamaeraphis glauca laevigata Beal, Grasses N. Am. 2: 155. 1896.

Chamaeraphis glauca perennis Beal, Grasses N. Am. 2: 156. 1896.

Chamaeraphis glauca geniculata Beal, Grasses N. Amer. 2: 156. 1896.

Chaetochloa imberbis Scribn. Bull. U. S. Dep. Agr. Agrost. 4: 39. 1897.

Chaetochloa penicillata Scribn. Bull. U. S. Dep. Agr. Agrost. 4:39. 1897.

Chaetochloa flava Scribn. Bull. U. S. Dep. Agr. Agrost. 4:39. 1897.

Chaetochloa versicolor Bickn. Bull. Torrey Club 25: 105. 1898.

Chaetochloa perennis Bickn. Bull. Torrey Club 25: 107. 1898.

Chaetochloa laevigata Scribn.; Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost.21:10,assynonym. 1900.

Part 4, 1931] POACEAE 321

Chaetochloa imberbis perennis Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:12. 1900.
Chaetochloa imberbis geniculata Seribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:12. 1900.
Chaetochloa imberbis streplobotrys Seribn. & Merr. Bull. U. S. Dep. Agr. Agrost. 21:13. 1900.
Chaetochloa purpurascens Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:13. 1900.
Chaetochloa gracilis Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:15. 1900.

Chaetochloa corrugata parviflora Scribn. & Merr. Bull. U. S. Dep. Agr. Agrost. soe 24. 1900.
Panicum glaberrimum E\l.; Scribn. & Merr. Cire. U.S. Dep. Agr. Agrost. 29:3, as synonym. 1901.
Chaetochloa Ventenatii Nash; Kearney, Contr. U. 5. Nat. Herb. 5:515. 1901.

Chaetochloa occidentalis Nash, in Britton, Man. 90. 1901.

Chaetochloa geniculata Millsp. & Chase, Field Mus. Publ. Bot. 3:37. 1903.

Setaria glauca geniculata Urban, Symb. Ant. 4:96. 1903.

Setaria glauca purpurascens Urban, Symb. Ant. 4:96. 1903.

Chamaeraphis imberbis Kuntze; Stuck. Anal. Mus. Nac. Buenos Aires III. 4:76. 1904.
Chamaeraphis gracilis Kuntze; Stuck. Anal. Mus. Nac. Buenos Aires III. 4: 76. 1904.
Chamaeraphis penicillata Presl; Stuck. Anal. Mus. Nac. Buenos Aires III. 4:76. 1904.
Panicum versicolor Nieuwl. Am. Midl. Nat. 2:64. 1911. Not P. versicolor Doell, 1877.
Panicum occidentale Nieuwl. Am. Mid. Nat. 2: 64. 1911. Not P. occidentale Scribn. 1899,

Plants perennial, producing short knotty branching rhizomes as much as 4 cm. long;
stems erect, spreading, or prostrate, tufted or solitary, as much as 1 meter tall, sometimes
dwarfed, glabrous, usually scabrous below the panicle, the base usually hard and wiry, often
more slender than the upper part; leaf-sheaths compressed-keeled, glabrous, sometimes sca-
brous toward the summit; ligule very short, densely ciliate; blades flat, scabrous, often glaucous,
and often more or less villous toward the base on the upper surface, glabrous or somewhat
scabrous beneath, mainly straight (not twisted as in S. /uiescens), as much as 20 cm. long and
8 mm. wide, usually narrower and shorter than this; panicle long-exserted, erect, evenly
cylindric, densely flowered, rounded or truncate (not narrowed) at summit, 1-10 cm. long
or in robust specimens longer, 4-8 mm. thick (excluding the bristles), yellow, purple, tawny,
or greenish, the axis densely and softly pubescent; branches pubescent like the axis, very
short, about | mm. long to the single spikelet, bearing about the middle a fascicle of irregular
branchlets, almost immediately dividing into bristles; bristles several, mostly 8-12, yellow
or purple, 1-3 times or even as much as 6 times as long as the spikelets, antrorsely scabrous;
spikelets 2—2.5 or even 3 mm. long, ovoid, plano-convex; first glume about one third
as long as spikelet, 3-nerved; second glume half to two thirds as long as spikelet, 5-nerved;
sterile lemma staminate or neuter, as long as the spikelet, 5- to 7-nerved, the palea well de-
veloped; fertile lemma transversely rugose with close narrow ridges.

TYPE LocaLity: Guadeloupe.

Distripution: Along the coast, Massachusetts to Florida and ‘Texas, and northward to Kansas
and Illinois; California and New Mexico, and southward through tropical America to Argentina and
Chile.

ILLUSTRATIONS: Trin. Ic. pl. 196 (as P. glaucum var.); Kunth, Rév. Gram. pl. 37 (as S. Vente-
natit); Bull. U. S. Dep. Agr. Agrost. 21: f. 2 (as C. imberbis penicillata), f. 3 (as C. purpurascens),
i) ee C. gracilis); Britt. & Brown, Ill. Fl. ed. 2. f. 392 (as C. imberbis); Contr. U. S. Nat. Herb. 22:

ll This species is exceedingly variable, but after a study of a great amount of material and
much field work it is impossible to segregate coherent groups. ‘The culms are sometimes single,
slender and weak, sometimes cespitose, sometimes stout, much-branched at base, spreading or
prostrate; the blades vary in width and the panicles in length. Much of the difference in general
appearance is due to the color and length of the bristles; the bristles are long early in the season
and in cultivated soil. ‘The differences appear not to be codrdinated. In occasional specimens the
sterile lemma is indurate and rugose like the fertile lemma. Sometimes the blades are very narrow,
only 2-3 mm. wide, but otherwise not distinct; this has been called Chaetochloa gracilis (Bull. U.S.
Dep. Agr. Agrost. 21:15. 1900; Contr. U.S. Nat. Herb. 17: 263. 1913).

7. Setaria tenax (Rich.) Desv. Opuse. 78. 1831.

Panicum tenax Rich. Act. Soc. Hist. Nat. Paris 1: 106. 1792.

Panicum impressum Nees, Agrost. Bras. 247. 1829.

Setaria impressa Kunth, Rév. Gram. Suppl. xii. 1830.

Panicum Sphaerocarpum Salzm.; Steud. Syn. Gram. 51. 1854. Not P. sphaerocarpum Ell. 1816.

Panicum amphibolum Steud. Syn. Gram. 51, 1854.

Panicum relia Salzm.; Steud. Syn. Gram. 51, as synonym. 1854. Not P. intermedium
Vahl, 1813.

Selaria biconvexa Griseb. Fl. Brit. W. Ind. 555. 1864.

Chaetochloa Salzmanniana Hitche. Contr. U. S. Nat. Herb. 17: 265. 1913.

Chaetochloa impressa Hitche. & Chase, Contr. U.S. Nat. Herb. 18: 350. 1917.

Setaria sphaerocarpa Hubbard, Contr. Gray Herb. 52:60. 1917.

Chaetochloa tenax Hitchc. Contr. U. S. Nat. Herb. 22: 176. 1920.

Plants perennial; stems glabrous, scabrous below the panicle, 1-1.5 meters tall, often
geniculate at base; leaf-sheaths glabrous or usually scabrous toward the summit, villous on

x
nS)

NORTH AMERICAN FLORA [VOLUME 17

the margin, densely hispid on the collar; ligule densely pilose, 2-3 mm. long; blades flat, more or
less scabrous, narrowed at base, acuminate at apex, as much as 35 cm. long and 2 cm. wide;
panicles rather densely flowered, narrowed toward summit but not attenuate, somewhat
interrupted or lobed below, 15-30 cm. long, 2-3 cm. wide, the branches ascending, the
lower about 2 cm. long, the axis villous with hairs 1-2 mm. long; bristles 1 or 2 below each
spikelet, 1-2 cm. long, flexuous, retrorsely scabrous and often antrorsely toward the base,
sometimes barblets directed different ways intermixed, pale or tawny, becoming implicate and
somewhat one-sided with age; spikelets subspheric, about 2 mm. long, very turgid on one side
and somewhat convex on the other; first glume about 1 mm. long or a little less, 5-nerved;
second glume about two thirds as long as the spikelet but at maturity pushed aside, exposing
nearly half the fertile lemma, 7- to 9-nerved; sterile lemma as long as the fertile, 5- to 7-nerved,
the nerves less distinct than those of the glumes, the palea well developed; fertile lemma very
turgid, yellowish-brown at maturity, rather indistinctly cross-wrinkled, the palea convex.

TYPE LocALity: Cayenne, French Guiana.

DISTRIBUTION: Southern Mexico; Cuba; Jamaica; Barbados; Panama to Brazil and Bolivia.

ILLUSTRATION: Contr. U. S. Nat. Herb. 22: 177. 7. 42.

Note: This species resembles S. vulpiseta, but is less robust and has retrorsely scabrous bristles
and subspheric spikelets. It was described by Grisebach (Fl. Brit. W. Ind. 555. 1864) as Setaria
Onurus, but the original Panicum Onurus Willd., from Montevideo, as described by Trinius (Mém.
Acad. St.-Pétersb. VI. 32: 226. 1834) is a different species, later described as Setaria caespitosa
Hack. & Arech.

8. Setaria verticillata (L.) Beauv. Agrost. 51,178. 1812.

Panicum verticillatum L. Sp. Pl. ed. 2.82. 1762.

Pennisetum verticillatum R. Br.; R. & S. Syst. Veg. 2: 488, as synonym. 1817.
Chamaeraphis italica verticillata Kuntze, Rev. Gen. 768. 1891.

Chamaeraphis verticillata Porter, Bull. Torrey Club 20: 196. 1893.

Txophorus verticillatus Nash, Bull. Torrey Club 22: 422. 1895.

Chaetochloa verticillata Scribn. Bull. U. S. Dep. Agr. Agrost. 4:39. 1897.

Plants annual, often much branched at base and geniculate-spreading; stems smooth,
scabrous below the panicle, as much as | meter tall, usually less; leaf-sheaths glabrous, or rarely
scabrous toward the summit, ciliate, keeled; ligule very short, densely ciliate; blades flat,
rather thin, scabrous on both surfaces, often more or less pilose on one or both surfaces with
short scattered hairs, usually 10-20 cm. long and 5-10 mm. wide; panicles erect but not
stiff, cylindric or somewhat tapering upward, more or less lobate or interrupted, especially
toward base, mostly 5-15 cm. long, 7-15 mm. wide, or in robust specimens as much as
2 em., the axis scabrous, or scabrous-hispid on the angles, more or less retrorsely so; branches
closely many-flowered, scabrous-hispid on the angles like the axis, the cluster oblong, 3-10
mm. long, the branchlets very short, bearing 1-4 spikelets, a bristle below each spikelet;
bristles 1-3 times as long as the spikelets, somewhat flexuous, retrorsely scabrous to base,
this often flattened; spikelets about 2 mm. long, oblong-elliptic, not very turgid on the convex
side; first glume about one third as long as the spikelet, 3-nerved; second glume and sterile
lemma as long as the spikelet, 5-nerved, the sterile palea usually partially developed; fertile
lemma finely cross-wrinkled.

TYPE LocaLity: Southern Europe.

DISTRIBUTION: Widely distributed in the warmer parts of the Eastern Hemisphere; introduced
in the United States from Massachusetts to North Dakota, and southward to Virginia and Missouri;
SDare, New Mexico; Utah; California; Coahuila to Guatemala; Cuba; Bermuda; occasional
elsewhere.

Intustrations: Trin. Ic. pl. 202; Reichenb. Ic. Fl. Germ. 1: pl. 47, no. 1465; Host, Gram.
Austr. 2: pl. 13; Bull. U. S. Dep. Agr. Agrost. 17: f. 403; 21: f. 5 (as C. brevispica), f. 6; Britt. &
Brown, Ill. Fl. f. 280; ed. 2. f. 390; Contr. U. S. Nat. Herb. 22: 179. f. 43.

9. Setaria scandens Schrad.; Schultes, in R. & S. Syst. Veg.
Mant. 2: 279. 1824.

Panicum scandens Trin. Gram. Pan. 166. 1826.

Panicum Trinii Kunth, Enum. Pl.1:151. 1833.

Panicum scandens vulgare D6ll, in Mart. Fl. Bras. 2?: 171. 1877.
Panicum scandens longiseta D6ll, in Mart. Fl. Bras. 2?: 171. 1877.
Chaetochloa scandens Scribn.; Donn. Smith, Pl. Guat. 5:91. 1899.

Plants annual, much branched below, erect or soon geniculate-spreading; stems slender,
sometimes rooting at the lower nodes, as much as 80 cm. long, glabrous, sometimes appressed-

Part 4, 1931] POACEAE 323

pilose at the nodes, especially below the margin of the sheath; leaf-sheaths glabrous or sparsely
appressed-pilose, or the lowermost densely pilose, the margin and collar densely pilose; ligule
densely ciliate, less than 1 mm. long; blades flat, linear-lanceolate, as much as 10 em. long and
1 cm. wide, scabrous especially on upper surface, usually sparsely, sometimes densely pilose on
both surfaces; panicles slender, erect, cylindric, densely flowered, sometimes slightly lobate or
interrupted especially at base, often purplish, as much as 8 cm. long, mostly less than 5 mm.
thick, the axis softly pubescent and also long-villous, the scattered hairs often longer than
the spikelets; branches very short, pubescent and sparsely villous like the axis; clusters of
bristles nearly sessile, divided into 3-5 short branchlets, each supporting a spikelet and 1-3
bristles; bristles somewhat flexuous but not becoming implicate, as long as the spikelets to twice
as long, antrorsely scabrous except near the tip, there more or less retrorsely scabrous; spikelets
about 1.5 mm. long, ovoid, turgid on the convex side; first glume about as long as the spikelet,
very broad, enveloping the base of the spikelet, 3-nerved; second glume nearly as long as the
spikelet, 5-nerved; sterile lemma as long as the spikelet or slightly exceeding the fertile lemma,
5-nerved, partly enveloping the fertile lemma, the first pair of nerves at the edges of the spike-
let, the outer pair on the convex side of the spikelet; fertile lemma transversely striate or
weakly rugose.
TYPE Loca.ity: Described from a garden specimen.

DISTRIBUTION: Guatemala to Paraguay and Bolivia; Jamaica; Cuba; Hispaniola.
IntusrraTions: Trin. Ic. pl. 201; Contr. U.S. Nat. Herb. 22: 181. f. 44.

10. Setaria tenacissima Schrad.; Schultes, in R. & S. Syst. Veg.
Mant. 2: 279. 1824.

Panicum tenacissimum Nees, Agrost. Bras. 238. 1829.
Chaetochloa tenacissima Hitche. & Chase, Contr. U.S. Nat. Herb. 18: 352. 1917.

Plants annual, mostly simple or little-branched; stems erect, slender, glabrous, scabrous
below the panicle, 1-2 meters tall, leaning on or clambering over other vegetation; leaf-sheaths
glabrous, antrorsely scabrous toward the summit, short-hispid on the margin and sparsely so
on the surface above, more or less hispid on the collar; ligule very short, densely ciliate; blades
flat, very scabrous on both surfaces and more or less pubescent especially beneath, mostly
10-15 cm., sometimes as much as 20 cm. long, mostly not more than 8 mm. wide, gradually
tapering from about the middle to the long-acuminate apex, rather abruptly narrowed at base;
panicles somewhat nodding or flexuous, rather densely flowered above, somewhat interrupted
toward the base, a little tapering toward the summit, as much as 15 cm. long and 1 cm. thick
(excluding bristles), the axis densely pubescent and sparsely villous with long weak hairs;
clusters of branchlets rather loose, 3-5 mm. long, dividing 2 or 3 times, each ultimate branch-
let or pedicel bearing a bristle, the corresponding spikelet sometimes suppressed, the cluster
bearing, therefore, usually not more than 8 spikelets and 8 bristles, the branchlet pubescent
but not villous; bristles flexuous, becoming implicate, about 1 cm. long, scabrous, antrorsely
below, retrorsely above; spikelets about 1.5 mm. long, often dark-purple; first glume about half
as long as the spikelet, 3-nerved; second glume and sterile lemma about as long as the fertile
lemma, 5-nerved, the sterile palea wanting; fertile lemma transversely rugose with numerous
fine ridges.

TYPE Loca.ity: Brazil.
DisrriBuTion: Guatemala to Brazil and Bolivia; Porto Rico; Hispaniola.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: 182. f. 45.

11. Setaria Grisebachii Fourn. Mex. Pl. Gram. 45. 1886.

Selaria pseudo-verticillata Fourn. Mex. Pl. Gram. 43. 1886.
Setaria laevis Fourn. Mex. Pl. Gram. 45. 1886.

Chaetochloa Grisebachii Scribn. Bull. U.S. Dep. Agr. Agrost. 4:39. 1897.

Chaetochloa Grisebachii ampla Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21: 36. 1900,
Chaetochloa Grisebachii mexicana Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21: 37. 1900.
Setaria mexicana Schafin.; Scribn. & Merr. Bull. U. S. Dep. Agr. Agrost. 21:37, as synonym. 1900.
Selaria yucatana W. Herrm. Beitr. Biol. Pl. 10:51. 1910.

Plants annual, branched at base, erect or spreading; stems as much as | meter tall but usu-
ally less, smooth, or scaberulous below the pubescent nodes and below the panicle; leaf-sheaths

324 NORTH AMERICAN FLORA [VOLUME 17

smooth, scabrous, or sparingly hispidulous, often papillose, densely ciliate, pubescent or hispid
on the collar; ligule a short densely ciliate membrane, scarcely 1 mm. long; blades flat, mostly
rather lax, erect or ascending, straight, puberulent and scabrous, as much as 25 cm. long and
1.5 cm. wide, usually less than 15 cm. long and 1 cm. wide; panicle loosely flowered, narrow,
tapering toward apex, mostly less than 15 cm. long, the axis scabrous and, except the lower
part, also villous; branches rather densely flowered, the lower somewhat distant, sometimes
as much as 2.5 em. long, spreading, usually 5-10 mm. long, and, except the lower, approxi-
mate; ultimate branchlets about 0.5 mm. long, bearing a single spikelet and a single bristle
below, the spikelet sometimes rudimentary, thus bringing the bristles in pairs; bristles 5-15
mm. long, sometimes shorter, flexuous, antrorsely scabrous, green or purplish; spikelets about
2 mm. long, moderately turgid on the convex side; first glume one fourth to one third the length
of the spikelet, 3-nerved; second glume a little shorter than the spikelet, 5-nerved; sterile lemma
as long as the fertile lemma, 5-nerved, the palea small; fertile lemma acute, finely cross-
wrinkled.
TYPE LocaLity: Orizaba, Mexico.

DISTRIBUTION: Texas to Arizona, and southward to Oaxaca.
ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost. 21: f. 20, 21; Coatr. U. S. Nat. Herb. 22: 184.
40.

12. Setaria magna Griseb. Fl. Brit. W. Ind. 554. 1864.

Chamaeraphis magna Beal, Grasses N. Am. 2: 152. 1896.
Chaetochloa magna Scribn. Bull. U.S. Dep. Agr. Agrost. 4:39. 1897.

Plants annual, robust, erect, usually not branched at base, sparingly branched above,
the branches erect; stems as much as 4 meters tall, rarely taller, and 2 cm. thick at base, smooth,
scabrous below the panicle; leaf-sheaths smooth or scabrous at summit, hispid-ciliate on margins;
ligule a densely and stiffly hispid membrane, 1—2 mm. long; blades flat, scabrous, as much as
0.5 meter long and 3.5 cm. wide; panicles densely flowered, nodding, often interrupted at base,
tapering at each end, as much as 40 cm. long and 3 em. thick, those of the branches much
smaller, the axis densely pubescent and also villous with ascending hairs about 1 mm. long;
branches as much as 1.5 ecm. long, many-flowered; bristles somewhat flexuous, 1 or 2 below
each spikelet, 1-2 em. long; spikelets about 2 mm. long, not very turgid on the convex side;
first glume about one third as long as the spikelet, 3-nerved; second glume about as long as
the spikelet, 5-nerved; sterile lemma as long as the spikelet, 7-nerved, the sterile palea well
developed; fertile lemma smooth.

‘TYPE LOCALITY: Jamaica.

DIsTRIBuTION: Along the coast, New Jersey to Florida and Texas; Jamaica; Porto Rico; Guade-
loupe; Costa Rica.

ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost. 17: f. 402; Britt. & Brown, Ill. Fl. ed. 2. f. 395;
Contr. U. S. Nat. Herb. 22: 185. f. 47.

13. Setaria ambigua Guss. Fl. Sic. Syn. 1: 114. 1843.

Panicum verticillatum ambiguum Guss. Prodr. Fl. Sic. 80. 1827.

Setaria verticillata ambigua Parl. Fl. Palerm. 1:36. 1845.

Panicum ambiguum Hausskn. Oesterr. Bot. Zeitschr. 25: 345. 1875.
Chamaeraphis italica ambigua Kuntze, Rev. Gen. 2: 768. 1891.

Chaetochloa ambigua Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:18. 1900.

Plants with the aspect of Sefaria verticillata; differing in the longer ligule, scabrous but
not pilose leaf-blades, and the antrorsely scabrous bristles. The bristles are mostly 2-3 times
as long as the spikelets and at maturity are spreading and more or less implicate. This may
be only a variety of Setaria verticillata or of S. viridis, between which it seems to be intermediate.
It is retained as a species because it cannot be definitely referred to either of the two species
mentioned.

TYPE LOCALITY: Sicily.

DISTRIBUTION: Central and southern Europe; sparingly introduced at Philadelphia, Washington

and Mobile.
ILLUSTRATION: Bull. U.S. Dep. Agr. Agrost. 21: f. 7.

Part 4, 1931] POACEAE 32%

14. Setaria viridis (L.) Beauv. Agrost. 51, 178. 1812.

Panicum viride L. Syst. Nat. ed. 10.870. 1759.

Pennisetum viride R. Br.; R. & S. Syst. Veg. 2: 489, assynonym. 1817.
Setaria Weinmanni R. & S. Syst. Veg. 2: 490. 1817.

Panicum viride brevisetum DOll, Rhein. Fl. 128. 1843.

Selaria viridis Weinmanni Borbas, Math. Term. Kozlem. 15: 310. 1878.
Panicum italicum viride Korn. in Korn. & Wern. Handb. Getreid. 1: 277. 1885.
Chamaeraphis italica viridis Kuntze, Rev. Gen. 767. 1891.
Chamaeraphis viridis Millsp. Bull. W. Va. Agr. Exp. Sta. 2: 466. 1892.
Ixophorus viridis Nash, Bull. Torrey Club 22: 423. 1895.

Chaetochloa viridis Scribn. Bull. U.S. Dep. Agr. Agrost. 4:39. 1897.
Setaria viridis breviseta Hitche. Rhodora 8: 210. 1906.

Plants annual, usually branched at base, sometimes geniculate-spreading; stems smooth,
scabrous below panicle, usually 20-40 cm. tall, sometimes as much as 1 meter; leaf-sheaths
smooth, or scabrous toward the summit, ciliate on the margin and sometimes a little on the
collar; ligule very short, densely ciliate; blades flat, linear-lanceolate, straight (not twisted),
scabrous especially on the upper surface, usually less than 15 cm. long, commonly less than
1 em. wide, sometimes as much as 15 mm. wide; panicle erect or somewhat nodding, densely
flowered, green or purple, tawny, cylindric but tapering a little at the summit (the smaller
ones ovate), rarely as much as 10 cm. long, usually less than 7 cm., commonly 5-8 mm.
thick (excluding bristles), the axis densely pubescent and also villous with numerous hairs
about 1 mm. long; branches very short, bearing several (mostly 5 or 6) spikelets, the rachis
pubescent; bristles 1-3 below each spikelet, mostly 3-4 times as long as the spikelet,
antrorsely scabrous, greenish or rarely purplish; spikelets 2-2.5 mm. long, elliptic, not
very turgid on the convex side; first glume one third to one fourth as long as the spikelet,
3-nerved; second glume and sterile lemma about as long as the spikelet or the former a little
shorter, 5-nerved, the sterile palea not fully developed; fertile lemma finely transversely
wrinkled or ridged.

TYPE LocaLity: Europe.

DistTRIBuTION: Eurasia; introduced in North America from Newfoundland to British Columbia,
and southward to Mexico; Costa Rica; Bermuda.

ILLUSTRATIONS: Trin. Ic. pl. 203; Reichenb. Ic. Fl. Germ. 1: pl. 47, no. 1467; Host, Gram,

Austr. 2: pl. 14; Bull. U. S. Dep. Agr. Agrost. 7: f. 65; Britt. & Brown, Ill. Fl. f. 282; ed. 2. f. 393;
Contr. U.S. Nat. Herb. 22: 187. f. 48.

15. Setaria italica (L.) Beauv. Agrost. 51, 170, 178. 1812.

Panicum italicum 1. Sp. P1.56. 1753.

Panicum germanicum Mill. Gard. Dict. ed. 8. Panicum no. 1. 1768.
Panicum italicum germanicum Koeler, Descr. Gram. 17. 1802.
Pennisetum italicum R. Br. Prodr. 195. 1810.

Setaria californica Kellogg, Proc. Casif. Acad. 1:27. 1855.
Chamaeraphis italica Kuntze, Rev. Gen. 767. 1891.

Ixophorus italicus Nash, Bull. Torrey Club 22: 423. 1895.
Chaetochloa italica Scribn. Bull. U.S. Dep. Agr. Agrost. 4: 39. 1897.

‘A cultivated form of S. viridis, differing in being more robust, with broader leaf-blades,
and larger lobate panicles. The stem may be as much as | em. thick, the blades as much as
3 cm. wide, and the heads as much as 30 cm. long. At maturity the fruit becomes very turgid
and spreads apart the glumes and sterile lemma, and is distinctly longer than these. ‘The head,
in some forms, becomes heavy and nodding, and distinctly lobate. ‘The color of the fruit
varies from tawny to red, brown, and black. ‘The bristles are 1-3 times as long as the spike-
let, green, purple, or brown. ‘The fruit is smooth or obscurely cross-wrinkled and may be as
much as 3 mm. long. In the cultivated forms the rachilla disarticulates above the sterile
lemma so that the fruit at maturity readily falls from the spikelet, and hence shells out when
the heads are threshed. The plants propagate themselves in fields and waste places and then
tend to revert to a more primitive form. These uncultivated plants are often difficult to
distinguish from forms of Selaria viridis. ‘This is especially true in immature specimens,
as the disarticulation of the fruit is evident only at maturity, and, even then, in the uncultivated
plants, is often less marked.

TYPE LOCALITY: India.

326 NORTH AMERICAN FLORA [VOLUME 17

DISTRIBUTION: Cultivated throughout the temperate regions of the world; escaped from
cultivation, and appearing more or less as a waif in waste places throughout the United States.

ILLUSTRATIONS: Vasey, Agr. Grasses U.S. 16; ed. 2. 19; Trin. Ic. pl. 198; Host, Gram. Austr. 4:
pl. 14; Bull. U. S. Dep. Agr. Agrost. 7: f. 68; 21: f. 9; Hitchc. Text-book Grasses f. 24, 25; Britt. &
Brown, Ill. Fl. f. 283; ed. 2. f. 354; Contr. U. S. Nat. Herb. 22: 190. f. 49. :

Norte: There are many varieties in cultivation differing in the length and color of the bristles,
the color of the fruit, and the size and degree of lobing of the panicle or head. The varieties are
discussed by Kérnicke (Kérn. & Wern. Handb. Getreid. 1: 270-279. 1885) and by Hubbard (Am.
Jour. Bot. 2: 169. 1915).

16. Setaria longipila Fourn. Mex. Pl. Gram. 47. 1886.
Chaetochloa longipila Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:22. 1900.

Plants annual; stems erect, branching at base, glabrous, scabrous just below the panicle,
30-40 cm. tall, the nodes hispidulous; leaf-sheaths mostly glabrous, sometimes scaberulous at
summit or sparsely hispid, densely ciliate on the margin, hispid on the collar; ligule a dense
line of stiff white hairs 2-3 mm. long; blades flat, 7-10 cm. long, as much as 1 cm. wide,
scabrous and sometimes sparsely hispidulous, narrowed toward each end; panicles spike-like,
cylindric, somewhat interrupted, rather densely flowered, narrowed toward the summit, 4-7 em.
long, about 5 mm. wide, the axis thickly beset with white, ascending, rather stiff, flexuous
hairs about 2 mm. long; branches short and ascending, the rachis somewhat villous like the
main axis; bristles mostly one below each spikelet, mostly 3-5 cm. long, antrorsely scabrous;
spikelets about 1.7 mm. long, turgid on the convex side; first glume about half as long as the
spikelet, 3-nerved; second glume about as long as the fertile lemma or very slightly shorter,
5-nerved, somewhat pointed; sterile lemma as long as the fertile, 5-nerved, slightly pointed;
fertile lemma sharply transversely rugose.

TYPE LOCALITY: Mexico.

DISTRIBUTION: Mexico, Guatemala, and Salvador.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: 191. f. 50.

17. Setaria corrugata (Ell.) Schultes, in R. & S. Syst. Veg.
Mant. 2: 276. 1824.

Panicum corrugatum Ell. Bot. S.C. & Ga. 1: 113. 1816.

Pennisetum corrugatum Nutt.; Schultes, in R. & S. Syst. Veg. Mant. 2: 276, assynonym. 1824.
Chamaeraphis corrugata Kuntze, Rev. Gen. 770. 1891.

Chaetochloa corrugata Scribn. Bull. U.S. Dep. Agr. Agrost. 4:39. 1897.

Chaetochloa hispida Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21: 25. 1900.

Setaria hispida K. Schumann, Bot. Jahresb. 28'!: 417. 1902.

Plants annual, branched at base, erect or geniculate-spreading; stems scabrous or the lower
part smooth, more or less appressed-hispid at the nodes, as much as | meter tall; leaf-sheaths
compressed-keeled, scabrous at least toward the summit, villous on the margin or sometimes
appressed-pilose all over; ligule a densely ciliate membrane about 1 mm. long; blades flat,
gradually narrowed to the base and to the acuminate apex, scabrous on both surfaces, as
much as 30 cm. long and 1 cm. wide, the middle culm blades commonly 15—25 cm. long and
less than 5 mm. wide, rarely sparsely pilose; panicles densely flowered, cylindric, in larger
specimens sometimes interrupted at base, as much as 15 cm. long, or usually less than 10 cm.,
the axis densely hispid-scabrous, and also rather densely villous with ascending hairs about
1 mm. long; branches 1-3 mm. long, hairy, bearing several spikelets (mostly 5 or 6), and
1-3 bristles below each spikelet; bristles somewhat flexuous, antrorsely scabrous, mostly
about 3 times as long as the spikelets, or as much as 2 cm. long, green, tawny, or purple;
spikelets about 2 mm. long, turgid on the convex side; first glume about half as long as the
spikelet, 3-nerved; second glume a little shorter than the spikelet, 5-nerved; sterile lemma as
long as the spikelet, 5-nerved; fertile lemma coarsely transversely rugose.

TYPE LocaLity: Savannah, Georgia.

DistTRipuTION: Along the coast, North Carolina to Florida and Louisiana; Cuba.

fo ate Bull. U.S. Dep. Agr. Agrost. 7: f. 66; 21: f. 11, 13; Contr. U.S. Nat. Herb. 22:

Part 4, 1931] POACEAE 327

18. Setaria Liebmanni Fourn. Mex. Pl. Gram. 44. 1886.

Setaria rariflora Presi, Rel. Haenk. 1:313. 1830. Not S. rariflora Mikan, 1821.
Panicum rariflorum Presl; Steud. Syn. Gram. 51. 1854.
Panicum dissitiflorum Steud. Syn. Gram. 51, as synonym. 1854.
Chamaeraphis caudata pauciflora Vasey; Beal, Grasses N. Am. 2: 158. 1896.
Chaetochloa Liebmanni Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:31. 1900.
Chaetochloa Liebmanni pauciflora Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:33. 1900.
Plants annual, often branched at base; stems as much as | meter tall, or usually less than 50
em., glabrous, scabrous just below the panicle, the nodes glabrous or puberulent; leaf-sheaths
glabrous, the margin ciliate, the collar a more or less hispidulous ridge; ligule a short, densely
ciliate membrane; blades flat, rather thin, as much as 20 cm. long and 2 em. wide, usually
about 1 cm. wide, narrowed toward both ends, scabrous, especially beneath; panicles loosely
flowered, cylindric, tapering at each end, often nodding or flexuous, as much as 30 em. long,
or usually 10-20 cm., the axis angled or channeled, scabrous or scabrous-hispidulous; branches
ascending, loosely arranged, scabrous like the axis, as much as 2.5 em. long; branchlets less
than I mm. long, bearing one bristle below each spikelet; bristles slender, flexuous, antrorsely
scabrous, 7 to 15 mm. long; spikelets ovate, about 2 mm. long, rather turgid on the convex
side, rather prominently nerved; first glume one third or one fourth as long as the spikelet,
3-nerved; second glume about four fifths as long as the fertile lemma, 5-nerved, with an
additional accessory pair on the outside; sterile lemma as long as the fertile, 5-nerved, with an
accessory pair like the second glume, the palea wanting; fertile lemma somewhat pointed,
gibbous, coarsely and strongly transversely rugose.

TYPE LOCALITY: Manantial, Mexico.

DISTRIBUTION: Arizona to Oaxaca; Nicaragua.

ILLustRations: Trin. Ic. pl. 96C; Bull. U.S. Dep. Agr. Agrost. 21: f. 23 (as Chaetochloa caudata) ;
Contr. U. S. Nat. Herb. 22: 193. f. 52.

19. Setaria latifolia (Scribn.) W. Herrm. Beitr. Biol. Pfl. 10:
55. 1910.

Chaetochloa latifolia Scribn. Bull. U.S. Dep. Agr. Agrost. 11: 44. 1898.
Chaetochloa latifolia breviseta Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:31. 1900.

Plants annual, branching at the base; stems erect or geniculate-spreading, 20-40 cm.
tall, more or less scabrous, especially below the hispidulous or pubescent nodes and below
the panicle; leaf-sheaths papillose-hispid, papillose, or glabrate, densely ciliate; ligule a densely
ciliate membrane less than 1 mm. long; blades flat, mostly less than 10 cm. long, as much as
1.5 mm. wide, rounded or somewhat cordate at base, rather abruptly narrowed at the apex,
scabrous and also sparsely papillose-hispid; panicles loosely cylindric, tapering above, more or
less interrupted or lobed, mostly 5—8 cm. long, the axis scabrous or pubescent and also villous,
the hairs weak and spreading, | mm. long; branches short, ascending, the longer as much as
5 mm. long; branchlets about 1 mm. long, bearing a single bristle below the spikelets; bristles
flexuous, angled, antrorsely scabrous, 5-10 mm. long; spikelets about 2 mm. long or a little
longer, moderately turgid on the convex side; first glume one third the length of the spikelet,
3-nerved; second glume a little shorter than the fertile lemma, 5-nerved; sterile lemma as long
as the fertile, 5-nerved, the palea well developed; fertile lemma strongly and coarsely trans-
versely rugose.

Type LocaLity: Durango, Mexico.
DIsTRIBUTION: Durango to Oaxaca; Brazil. .
ILLusTRATIONS: Bull. U. S. Dep. Agr. Agrost. 21: f. 17; Contr. U. S. Nat. Herb. 22: 195, f. 53.

20. Setaria-smacrosperma K. Schumann, Bot. Jahresb. 28':
417. 1902.
Chaetochloa macrosperma Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:33. 1900.

Plants perennial, often in large tufts; stems usually more or less geniculate at base, and
often rooting at the lower nodes, smooth, scabrous below the panicle, rather stout, mostly
1-1.5 meters tall, the nodes glabrous; leaf-sheaths keeled, glabrous, the margin villous, usually
hispidulous on the collar; ligule a ciliate membrane, 1-3 mm. long; blades flat, very scabrous

328 NORTH AMERICAN FLORA [VOLUME 17

on the upper surface, smooth or scaberulous beneath, narrowed at the base, as much as 50 cm.
long and 2 cm. wide; panicles rather loose, tapering above, as much as 25 cm. long, the secondary
panicles often much smaller and more compact, the branches ascending, as much as 2 cm. long,
about equally distributed, the panicle thus not being interrupted or lobed, the axis scabrous-
pubescent and also loosely or sparsely villous with hairs 1-2 mm. long, the hairs rarely wanting;
bristles single below each spikelet but often seemingly in pairs because of the abortion of
spikelets, straight or obscurely flexuous, antrorsely scabrous, 1.5—3 cm. long, greenish or
yellowish; spikelets about 3 mm. long, lanceolate-ovate, not strongly turgid on the convex
side, pale or greenish; first glume abate one third the length of the spikelet, 3-nerved; second
glume two thirds to three fourths as long as the fertile lemma, mostly 5-nerved, sometimes
6- or 7-nerved; sterile lemma as long as the fertile, 5-nerved, concave or sulcate, the palea
narrow, about half as long as its lemma; fertile lemma pale, acute or somewhat pointed, finely
and not very distinctly cross-wrinkled, the surface appearing cellular.

TYPE Loca.Lity: Florida.

DISTRIBUTION: Florida and Bahama Islands.

ILLUSTRATIONS: Bull. U.S. Dep. Agr. Agrost. 7: f. 67 (as C. composita); 21: f. 18; Contr. U.S.
Nat. Herb. 22: 196. f. 54.

21. Setaria villosissima (Scribn. & Merr.) K. Schumann, Bot.
Jahresb. 28': 417. 1902.

Chaetochloa villosissima Scribn. & Merr. Bull. U. S. Dep. Agr. Agrost. 21:34. 1900.

Plants perennial; stems erect or decumbent at base, glabrous, as much as | meter tall,
nodes more or less pubescent; leaf-sheaths glabrous or somewhat hispidulous, often scabrous
toward the summit, compressed-keeled, especially the lower, hispid on the collar, villous on
the margin; ligule densely pilose, 2-3 mm. long; blades flat, scabrous and villous, or scabrous
only, 15-30 cm. long, 5-8 mm. wide; panicles rather loose, more or less interrupted, tapering
at the summit, as much as 23 cm. long, the branches ascending, the lower as much as 2 cm.
long, the axis angled, scabrous, villous; bristles single below each spikelet, flexuous, antrorsely
scabrous, 1.5-2.5 cm. long; spikelets lanceolate-ovate, acutish, not strongly turgid on the
convex side, about 3 mm. long, pale or greenish; first glume one third as long as the spikelet,
3-nerved; second glume nearly as long as the fertile lemma, 5-nerved (rarely 7-nerved); sterile
lemma as long as the fertile, 5-nerved, concave or sulcate, the palea narrow, less than 1 mm.
long; fertile lemma lanceolate, the tip rather pointed, incurved, the surface finely but sharply
cross-wrinkled.

TYPE LOCALITY: San Diego, Texas.

DIstTRIBUTION: Texas and Arizona.
ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost. 21: f. 19; Contr. U. S. Nat. Herb. 22: 197. f. 55.

22. Setaria setosa (Sw.) Beauv. Agrost. 51, 178. 1812.

Panicum setosum Sw. Prodr. 22. 1788.

Panicum caudatum Lam. Tab. Encycl. 1:171. 1791.

Panicum brachiatum Poir. in Lam. Encyc. Suppl. 4: 282. 1816.

Setaria caudata R. & S. Syst. Veg. 2: 495. 1817.

Setaria elongata Spreng.; Schultes, in R. & S. Syst. Veg. Mant. 2: 280. 1824.
Setaria brachiata Kunth, Rév. Gram. 47. 1829.

Panicum paractaenoides ‘Trin. Mém. Acad. St.-Pétersb. VI. 32: 219. 1834.
Panicum dumetorum A. Rich.; Steud. Syn. Gram. 49. 1854.

Panicum restitutum Steud. Syn. Gram. 53. 1854.

Setaria setosa caudata Griseb. Fl. Brit. W. Ind. 555. 1864.

Pennisetum Swartzii F. Mill. Fragm. 8: 110. 1873.

Chamaeraphis setosa Kuntze, Rev. Gen. 768. 1891.

Chamaeraphis selosa caudata Kuntze, Rey. Gen. 769. 1891.

Chamaeraphis caudata Britton, Ann. N. Y. Acad. 7: 264. 1893.
Chaetochloa setosa Scribn. Bull. U.S. Dep. Agr. Agrost. 4:39. 1897.
Chaetochloa caudata Scribn. Rep. Mo. Bot. Gard. 10: 52. 1899.

Setarvia paractaenoides Urban, Repert. Sp. Nov. 15:98. 1917.

Plants perennial; stems erect, spreading, or decumbent at. base, often wiry, sometimes
prostrate and woody at base with upright branches, glabrous, scabrous below the panicle, some-
times hispidulous about the nodes, mostly not more than 1 meter tall; leaf-sheaths glabrous
or rarely pubescent, the lower often keeled, often overlapping, ciliate, hispidulous or rarely

Part 4, 1931] POACEAE 329

glabrous on the collar; ligule densely ciliate, about 1 mm. long; blades flat or folded, usually
rather firm and stiffly spreading, glabrous beneath, scabrous on upper surface, or often pubes-
cent on both surfaces, usually 15-20 em. long, sometimes as much as 30 cm. long, mostly
5-10 mm. wide, sometimes wider; panicles mostly narrow, sometimes loosely spike-like,
sometimes rather open, attenuate at summit, usually 10-20 cm. long, rarely as much as
40 em., the branches short and crowded or ascending and 1-2 cm. long, approximate or,
especially the lower, 1-3 cm. distant, these rarely spreading or somewhat reflexed, the axis
villous with hairs as much as 1 mm. long; bristles mostly one below each spikelet, flexuous,
antrorsely scabrous, mostly 5-10 mm. long, sometimes scarcely exceeding the spikelets;
spikelets about 2 mm. long, rather strongly turgid on the convex side; first glume nearly half
as long as the spikelet, 3-nerved; second glume about two thirds as long as the fertile lemma,
5-nerved; sterile lemma about as long as the fertile, 5-nerved, the palea well developed; fertile
lemma acutish, finely but strongly cross-ridged.

TYPE LOCALITY: Jamaica, _

DIsTRIBUTION: West Indies; Chacachacare, Trinidad; Colombia.

ILLusTRATIONS: Trin. Ic. pl. 95; Contr. U. S. Nat. Herb. 22: 199. f. 56, 57.

Nore: In habit this species is rather variable, the differences being due chiefly to the length
of the bristles, the length and distance of the branches of the panicle, and the relative amount of
foliage. The usual form has rather densely flowered panicles with short ascending approximate
branches and bristles 5-10 mm. long. An extreme form (Panicum brachiatum Poir.), growing on
dry brushy hillsides, has wiry, often woody, sometimes decumbent and rooting stems, rather few and
distant leaves and loose panicles with distant spreading sometimes reflexed branches as much as

5 cm. long, and short bristles. However, there are all gradations connecting this with the usual
form.

23. Setaria rariflora Mikan; Trin. Neue Entdeck. 2:78. 1821.

Setaria vaginata Spreng. Syst. 42: (Cur. Post.) 33. 1827.
Panicum triquetrum Willd.; D6ll, in Mart. Fl. Bras. 2?: 161, as synonym. 1877.
Chaetochloa rariflora Hitchc. & Chase, Contr. U.S. Nat. Herb. 18: 349. 1917.

Plants perennial, tufted; stems erect, or decumbent at base, glabrous, mostly 30-60 em.
tall; leaf-sheaths pubescent with short ascending hairs, or glabrate, keeled, mostly overlapping;
ligule densely ciliate, less than 1 mm. long; blades elongate and narrow, pubescent on both
surfaces, narrowed at base, usually 2-3 mm. wide, rarely more than 5 mm.; panicles narrow,
tapering above, 10-15 cm. long, often less, the axis loosely villous, the hairs mostly less than
1 mm. long; branches ascending, the lower 5-10 mm. long, or often shorter, the panicle then
being loosely or interruptedly spike-like; bristles usually one below each spikelet, flexuous,
antrorsely scabrous, 4-7 mm. long, or often scarcely exceeding the spikelets; spikelets about
2 mm. long, turgid on the convex side; first glume a little less than half the length of the spike-
let, 3-nerved; second glume about two thirds as long as the spikelet, 7-nerved; sterile lemma as
long as the fertile, 5- to 7-nerved, the palea well developed; fertile lemma acutish, finely and
sharply cross-ridged. ;

Type Locauity: Brazil.

DISTRIBUTION: Porto Rico and Cuba to Brazil; on ballast at Mobile, Alabama.

ILLusTRATION: Contr. U. S. Nat. Herb. 22: 201. f. 58

Nore: This species differs from S. sefosa chiefly in the long narrow blades and the usually
narrower and less bristly panicle. The second glume is shorter and usually 7-nerved. The two
forms are given specific rank because the specimens from Brazil agree in having slender rather lax
blades and narrow few-flowered interruptedly spike-like panicles like the type of S.rariflora. Setaria
selosa is confined to the West Indies and adjacent parts of South America; there are no specimens
known from Brazil. In Trinidad it is found only on the outlying islet Chacachacare. Because of
the slightly different aspect and the different geographical range it seems better to recognize the two
forms as species rather than varieties, though they are closely related.

24. Setaria vulpiseta (Lam.) R. & S. Syst. Veg. 2: 495. 1817.

Panicum vulpisetum Lam. Encyc. 4: 735 (err. typ. 745). 1798.
Setaria composita H.B.K. Nov. Gen. & Sp. 1: 111. 1815.

Setaria polystachya Schrad.; Schultes, in R. & S. Syst. Veg. Mant. 2: 277. 1824.

Panicum compositum Nees, Agrost. Bras. 244. 1829. Not P. compositum 1,. 1753.

Panicum macrourum Trin. Mém. Acad. St.-Pétersb. VI. 3: 227. 1834.

Setaria Alopecurus “hort. Gor.’’; Trin. Mém. Acad. St.-Pétersb. V1. 3*: 227, as synonym. 1834.
Panicum amplifolium Steud. Syn. Gram. 53. 1854.

Panicum subsphaerocarpum Salzm.; Schlecht. Linnaea 31: 483. 1862.

330 NORTH AMERICAN FLORA [VoLuME 17

Chamaeraphis setosa vulpiseta Kuntze, Rev. Gen. 769. 1891.

Chamaeraphis composita Kuntze; Beal, Grasses N. Am. 2: 154. 1896.
Chaetochloa composita Scribn. Bull. U. S. Dep. Agr. Agrost. 4:39. 1897.
Chaetochloa vulpiseta Hitchc. & Chase, Contr. U.S. Nat. Herb. 18: 350. 1917.

Plants perennial, branching at base, often in large tufts; stems glabrous, stout, often
decumbent at base, as much as 2 meters tall; leaf-sheaths keeled, glabrous, or scaberulous or
hispidulous toward the summit or rarely all over, hispid on the margin and densely hispid on
the well-marked ridge of the collar, the hairs yellowish, as much as 4 mm. long; ligule densely
hispid like the collar, 2 mm. long; blades flat, gradually narrowed from the middle toward both
ends, the larger somewhat plaited, scabrous, especially beneath, as much as 50 cm. long and
3 cm. wide; panicles rather densely and evenly flowered, tapering toward the apex and often
somewhat tapering at base, as much as 30 cm. long and 4-5 cm. wide (secondary panicles
much smaller, sometimes only 5 cm. long), the branches stiffly ascending or spreading, as
much as 2-3 cm. long and of about equal length except toward the summit, the axis densely
villous; bristles 1 or 2 at the base of each spikelet, slightly flexuous, brownish, antrorsely
scabrous, mostly 1—2 cm. long, appearing secund on the branches after the fall of the spikelets;
spikelets ovoid, 2—2.5 mm. long, pale, moderately turgid on the convex side; first glume
about half as long as the spikelet, 3-nerved; second glume two thirds to three fourths as long
as the fertile lemma, 7-nerved; sterile lemma as long as the fertile, 5-nerved, the palea well
developed; fertile lemma lanceolate, acutish, strongly and rather coarsely cross-wrinkled.

TYPE LOCALITY: Santo Domingo.

DISTRIBUTION: Southern Mexico and the West Indies (Porto Rico, Santo Domingo) to Argentina.

Note: The panicles sometimes resemble those of S. magna but are less densely flowered; the
fertile lemma is cross-wrinkled instead of nearly smooth. From S. macrosperma it is distinguished
by the smaller spikelets.

25. Setaria macrostachya H.B.K. Nov. Gen. & Sp. 1: 110. 1815.

Panicum macrostachyum Nees, Agrost. Bras. 245. 1829.

Panicum Onurus Willd.; Nees, Agrost. Bras. 251, assynonym. 1829.

Chamaeraphis setosa macrostachya Kuntze, Rev. Gen. 769. 1891.

Chaetochloa gibbosa Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21: 24. 1900.
Chaetochloa leucopila Scribn. & Merr. Bull. U. S. Dep. Agr. Agrost. 21: 26. 1900.
Chaetochioa macrostachya Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21: 29. 1900.
Chaetochloa rigida Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:30. 1900.

Setaria leucopila K. Schumann, Bot. Jahresb. 28': 417. 1902.

Chamaeraphis macrostachya Kuntze; Stuck. Anal. Mus. Nac. Buenos Aires III. 4:76. 1904.
Setaria Berlandieri W. Herrm. Beitr. Biol. Pfl. 10:56. 1910.

Plants perennial, tufted, usually pale or glaucous, more or less hirsute around the base;
stems erect or geniculate at base, scabrous below the panicle and usually below the glabrous
or hispidulous nodes, 40-120 cm. tall; leaf-sheaths more or less compressed-keeled, glabrous or
usually scaberulous toward the summit, rarely pubescent, ciliate on the margin, the collar
hispidulous or glabrous; ligule densely ciliate, 1-3 mm. long; blades flat or folded, scabrous
on the upper surface, smooth or scabrous beneath, rarely pubescent on both surfaces, 15—
40 cm. long, 3-5 mm. wide; panicles spike-like, 10-25 cm. long, or sometimes shorter,
somewhat tapering above but not attenuate, more or less interrupted or lobed, sometimes
rather open below, the branches usually short, the axis pubescent and often also villous with
hairs 1-2 mm. long; bristles mostly single below each spikelet, 10-15 mm. long with shorter
ones intermixed, flexuous, antrorsely scabrous; spikelets pale (the nerves usually pale), 2—
2.5 mm. long, turgid on the convex side, sometimes strongly so at maturity; first glume about
half as long as the spikelet, 3-nerved; second glume two thirds to three fourths as long as the
spikelet, 5- to 7-nerved; sterile lemma as long as the fertile, 5-nerved, the palea narrow, a little
shorter than the lemma; fertile lemma rather sharply but finely marked with cross-wrinkles.

TYPE LocaLity: Guanajuato, Mexico.

DISTRIBUTION: Texas and Colorado to Arizona, and southward to Oaxaca; Haiti.

ILLUSTRATIONS: Bull. U.S. Dep. Agr. Bot. 12!: pl. 5 (as S. caudata); Vasey, Agr. Grasses U. S.
17. 1884 (as S. setosa); Bull. U.S. Dep. Agr. Agrost. 21: f. 14 (as C. leucopila) ; f. 15 (as C. composita) ;
21: f. 16; f. 24 (as C. setosa); Contr. U. S. Nat. Herb. 22: 204. f. 60; 205. f. 61.

Nore: The species is somewhat variable in habit and includes what Scribner and Merrill
(Bull. U.S. Dep. Agr. Agrost. 21: 27. f. 15. 1900) and Hitchcock (Contr. U.S. Nat. Herb. 17: 263.
1913) referred to Chaetochloa composita. The typical form is rather robust with flat blades 5-10
mm. wide, and large panicles 15-25 cm. long, the branches ascending, about 1 em. long, or even
as much as 2 cm. The commoner form of Texas and northern Mexico is less robust, the blades
narrower, 34 mim. wide, often folded, the panicles more compactly flowered and spike-like. There
ae sO many intermediate specimens that it seems impracticable to draw specific lines between the
orms.

Part 4, 1931] POACEAE 331

26. Setaria Scheelei (Steud.) Hitchce. Proc. Biol. Soc. Wash.
41: 163. 1928.

Selaria polystachya Scheele, Linnaea 22: 339. 1849. Not S. polystachya Schrad. 1824.
Panicum Scheelit Steud. Syn. Gram. 51. 1854.

Chaetochloa polystachya Scribn. & Merr. Bull. U.S. Dep. Agr. Agrost. 21:37. 1900.
Chaetochloa Scheelei Hitchce. Contr. U.S. Nat. Herb. 22: 207. 1920.

Plants perennial; stems 60-120 em. tall, erect or geniculate at base, compressed below,
glabrous, the nodes often appressed-pilose; leaf-sheaths compressed-keeled, glabrous, or scabrous
near summit or on the keel, or sometimes more or less hispid on the surface, the collar hispid;
ligule densely hispid, 1-2 mm. long; blades flat, scabrous or more or less pubescent, 15-
25 cm. long, as much as 1.5 cm. wide; panicle rather loose, 15-20 cm. long, tapering from near
the base, the lower branches as much as 3 cm. long, ascending, the axis scabrous-pubescent
and rather sparsely villous; bristles mostly 1-1.5 cm. long, rather numerous, flexuous,
antrorsely scabrous; spikelets a little more than 2 mm. long, pale; first glume about one third
as long as the spikelet, 3-nerved; second glume a little shorter than the fertile lemma, 5-nerved;
sterile lemma as long as the fertile, 5-nerved, the palea small and narrow; fertile lemma finely
cross-wrinkled.

TYPE Locality: New Braunfels, Texas.

DISTRIBUTION: Texas; Vera Cruz.

TILLustRaTIons: Bull. U.S. Dep. Agr. Agrost. 21: f. 22; Contr. U. S. Nat. Herb. 22: 208. f. 62.

Nore: This species is allied to S. macrostachya, from which it differs in the looser panicle with
longer ascending lower branches. ‘The broad flat blades distinguish it from the common form of
S. macrostachya in Texas.

DOUBTFUL SPECIES
Setaria falcifolia Fourn. Mex. Pl. Gram. 44. 1886. ‘‘Absque loco (Jurg. n. 622).”

70. IXOPHORUS Schlecht. Linnaea 31: 420. 1862.

A perennial grass with flat leaf-blades and an inflorescence composed of numerous secund
spikes racemose along a main axis. Spikelets oblong-lanceolate, nearly terete, nearly sessile,
each subtended by a slender flexuous bristle (sterile branchlet) longer than the spikelet.
Glumes membranaceous, the first short, the second about as long as the spikelet. Sterile
lemma similar to the second glume, staminate, the palea well-developed, as long as the lemma,
finally becoming broad and papery. Fertile floret chartaceous, flattened dorsally, shorter than
the lemma and palea, apiculate.

Type species, Urochloa uniseta Presl.

1. Ixophorus unisetus (Presl) Schlecht. Linnaea 31: 421,
747. 1862.

Urochloa uniseta Presl, Rel. Haenk. 1: 319. 1830.

Panicum unisetum Trin. Mém. Acad. St.-Pétersb. VI. 32: 217. 1834.
Ixophorus Schiedeanus Schlecht. Linnaea 31: 421. 1862.

Setaria uniseta Fourn.; Hemsl. Biol. Centr. Am. Bot. 3: 506. 1885.
Setaria Schiedeana Fourn.; Hemsl. Biol. Centr. Am. Bot. 3: 505. 1885.
Setaria cirrhosa Fourn. Mex. Pl. Gram. 43. 1886.

Panicum Palmeri Vasey, Contr. U.S. Nat. Herb. 1: 281. 1893.

Panicum Pringlei Vasey, Contr. U.S. Nat. Herb. 1: 363. 1895.

Ixophorus Pringlei Scribn. Bull. U.S. Dep. Agr. Agrost. 4:6. 1897.
Ixophorus Pringlei minor Scribn. Bull. U.S. Dep. Agr. Agrost. 4:7. 1897.
Panicum cirrhosum Scribn. & Merr. Bull. U. S. Dep. Agr. Agrost. 21:40. 1900.
Setaria pol yneura W. Herrm. Beitr. Biol. Pfl. 10:42. 1910.

Plants smooth, rather succulent, branching below, often pale or glaucous; stems erect or
geniculate at base, as much as | meter tall, often low or depauperate; leaf-sheaths more or
less compressed-keeled, the margin glabrous; ligule a thin lacerate membrane 1-2 mm. long;
blades linear or linear-elliptic, acuminate, as much as 60 cm. long and 4 cm. wide, usually
about 2 cm. wide, in depauperate specimens only 3 cm. long and 4 mm. wide, the margins
scabrous; panicle oblong, as much as 20 cm. long, the axis angled, scabrous; racemes or spikes
few to many, ascending or sometimes spreading, irregularly arranged, approximate above,

332 NORTH AMERICAN FLORA [VOLUME 17
distant below, often falcate, as much as 10 cm. long, usually about 5 cm., as many as 50 or in
depauperate specimens only 2 or 3, the rachis angled, scabrous, floriferous nearly to base;
spikelets secund in about 2 rows, 4-5 mm. long, about 1 mm. wide, nearly terete, acuminate,
pectinate, closely approximate, or somewhat distant below, ascending, nearly sessile, the single
bristle flexuous, smooth or nearly so, usually purplish, viscid, 1-2 times as long as the spikelet;
first glume broad and short, truncate or acutish, 0.5—1 mm. long, 3-nerved, rarely scaberulous;
second glume about as long as the spikelet or a little shorter, obtuse, weakly several-nerved;
sterile lemma appearing acute from the inrolling of the margin above, 5-nerved, often
scaberulous on the nerves, the palea as long as the lemma, the margins thin and wide, over-
lapping and inclosing the 3 large anthers, at maturity widening and more or less clasping the
lemma, becoming prominent and papery; fertile lemma dorsally compressed, oblong-elliptic,
pale, about 2.5 mm. long, 1 mm. wide, apiculate, minutely scaberulous-punctate, 5-nerved,
the outer pair of nerves on the edge, the margin inrolled over the palea below, the palea free
above.

TYPE LOCALITY: Mexico.
DISTRIBUTION: San Luis Potosi to Costa Rica.
ILLUSTRATION: Bull. U.S. Dep. Agr. Agrost. 4: pl. 7, II.

71. PENNISETUM Rich. in Pers. Syn. Pl. 1:72. 1805.

Penicillaria Willd. Enum. 1036. 1809.
Gymnothrix Beauv. Agrost. 59. pl. 13, f.6. 1812.

Annual or perennial, often branched grasses, with usually flat blades and dense spike-like
panicles. Spikelets solitary or in groups of two or three, surrounded by an involucre of bristles,
these not united or only at the very base, often plumose, falling attached to the spikelets;
first glume shorter than the spikelet, sometimes minute or wanting; second glume shorter
than or equaling the sterile lemma; fertile lemma chartaceous, smooth, the margin thin,
inclosing the palea.

Type species, Pennisetum typhoideum Rich.

Bristles of the fascicle about + cm. long; panicles oval, feathery. 1. P. villosum.
Bristles of the fascicle not more than 2 cm. long, most of them much

shorter; panicles cylindric.
Grain at maturity subglobose, bursting through the lemma and palea;

panicles solidly dense, 2 cm. or more thick. 2. P. glaucum.
Grain permanently inclosed in the lemma and palea; panicles not
solid, less than 2 cm. thick.
Fascicles, or most of them, with 2 or more spikelets (often but 1 in
depauperate specimens of no. 2).
Bristles free throughout.
Fascicles sessile. 5. P. purpureum.
Fascicles pedunculate. 4. P. orientale tri florum.

Bristles united at the base into a minute disk.
Stems slender, rarely more than 50 cm. tall; inner bristles
conspicuously plumose. 5. P. ciliare.
Stems stout, mostly 1—-1.5 meters tall; innermost bristles
only ciliate or plumose.
Innermost bristles not more than 2.5 cm. long, sparsély

ciliate. 6. P. Karwinskyi.
Innermost bristles, or some of them, 4-5 cm. long,
plumose at base. 7. P. vulcanicum.
Fascicles with but one spikelet.
Bristles conspicuously plumose. 8. P. setosum.

Bristles not plumose.
Panicles terminal on the primary stem and leafy branches
only.
Blades flat or involute-pointed only, 10 cm. or more

long.
Spikelets 2—2.5 mm. long; axis about 0.5 mm.
thick. 9. P. Antillarum.
Spikelets 4.5 mm. or more long; axis 1-3 mm.
thick.
Panicles dense, the spikelets obscured in the
bristles.

Bristles scant, most of them scarcely ex-
ceeding the spikelets or shorter, one con-
spicuously longer than the rest. 10. P. crinitum.

Part 4, 1931] POACEAE 333

Bristles numerous, most of them much longer
than the spikelet, one not conspicuously
longer than the rest. 11. P. nervosum.
Panicles relatively loose, the spikelets not ob-
scured in the bristles. 1
Blades involute, not more than 5 cm. long ]
Panicles terminal and axillary, the latter on elendee naked
peduncles, 1 to several from a sheath.

Blades elongate, rarely more than 12 mm. wide, tapering
into a long setaceous-involute tip; spikelets 6-7 mm.
long, the bristles mostly shorter. 14. P. durum.

Blades 15-40 mm. wide, if narrower not elongate, not

setaceous-tipped; spikelets 4.5-6 mm. long, some
of the bristles always longer.
Sterile lemma empty; panicles rather densely
flowered; most of the bristles not more than
once and a half the length of the spikelets.
Panicles dull-green; bristles scant, most of them
not exceeding the spikelet, the innermost about
twice as long. 15. P. distachyum.
Panicles tawny; bristles numerous, most of them
exceeding the spikelet, the innermost not con-
spicuously longer than the others. 16. P. prolificum.
Sterile lemma inclosing a well-developed palea
and usually a staminate flower; panicles loosely
flowered; most of the bristles about twice the
length of the spikele*. 17. P. bambusiforme.

. complanatum.
. domingense.

Who

moles)

1. Pennisetum villosum R. Br.; Fresen. Mus. Senckenb. 2:
134. 1837.

Pennisetum villosum humile Hochst.; A. Rich. Tent. Fl. Abyss. 2: 387. 1852.
Cenchrus villosus Kuntze, Rev. Gen. 32: 347. 1898.

Plants rather pale, perennial, at length forming dense clumps from a knotty crown;
stems ascending, 15-50 cm. tall, rarely 1 meter or more tall, commonly branching from the
lower nodes, mostly flattened or angled in drying, the uppermost joint villous at least below
the inflorescence, otherwise glabrous; leaf-sheaths loose, mostly overlapping, pilose along the
scarious margin and at the summit or glabrous; ligule a ring of fine hairs 1.5—2 mm. long;
blades ascending or spreading, 3-6 mm. wide, mostly elongate, the upper often exceeding the
inflorescence but in dwarf plants sometimes only 8-10 cm. long, flat or folded, sparsely pilose
on the upper surface or glabrous, the margins and sometimes the under surface scabrous;
panicle grayish-tawny, very dense, oval, 3-15 cm. long, 3-5 em. wide including the bristles;
fascicles short-pedicelled, with a tuft of white hairs at the base of the pedicel; spikelets 8-10 mm.
long; first glume about 1 mm. long, truncate, denticulate, scarcely nerved; second glume ovate-
lanceolate, acuminate, half as long as the spikelet; sterile floret staminate, lemma about as ©
long as the fertile, acuminate, several-nerved, scaberulous, the palea nearly as long as the
lemma; fertile floret similar to the sterile, somewhat firmer.

TYPE LocaLity: Abyssinia.

DistrispuTion: North Africa and Arabia; cultivated for ornament in North America, and occa-
sionally escaped.

ILLUSTRATIONS: Stand. Cycl. Hort. f. 2857; Contr. U.S. Nat. Herb. 22: f. 63.

2. Pennisetum glaucum (L.) R. Br. Prodr. 195. 1810.

Panicum glaucum L. Sp. Pl. 56. 1753.

Holcus spicatus L,. Syst. Nat. ed. 10. 1305. 1759.

Pennisetum typhoideum Rich. in Pers. Syn. Pl. 1:72. 1805.
Penicillaria spicata Willd. Enum. 1037. 1809.

Pennisetum spicatum R. & S. Syst. Veg. 2: 499, as synonym. 1817.
Penicillaria Plukeneti Link, Hort. Berol. 1: 221. 1827.

Cenchrus spicatus Kuntze, Rev. Gen. 37: 346. 1898.

Plants annual, branching at the base, robust, as much as 2 meters tall; stems simple, or
rarely branching, densely villous below the panicle, often minutely so below the nodes, other-
wise glabrous, the nodes usually appressed-pubescent; leaf-sheaths loose, mostly overlapping,
commonly scabrous and usually densely hairy on the margins toward the summit and on the
collar; ligule densely hairy, about 3 mm. long; blades flat, rather thin, cordate at base, some-
times as much as 5 cm. wide and | meter long, scabrous on both surfaces, the midnerve

334 NORTH AMERICAN FLORA [VoLuME 17

prominent; panicles cylindric, stiff, very dense, as much as 59 cm. long and 2-2.5 em. thick,
pale tawny tinged with purple, the stout axis densely villous; fascicles on densely villous
peduncles about 3 mm. long; bristles numerous, as long as the spikelets or longer, scabrous,
the inner one ciliate; spikelets 1-2, short-pedicelled, oval, about 3 mm. long; first glume short
or sometimes wanting, obtuse, ciliate, nerveless; second glume similar to the first but usually
longer; sterile lemma similar to the glumes but a little longer; fertile floret firm, oval, longer
than the sterile, the lemma nerveless below, 5-nerved above, densely ciliate, the palea about as
large and broad as the lemma, ciliate, villous on the back; caryopsis spreading apart the lemma
and palea, finally often becoming much larger than these.

Typr LocaLity: Ceylon.

DISTRIBUTION: The warmer parts of the Eastern Hemisphere; occasionally cultivated in the
United States and sometimes found as an escape. Known in the United States as pearl millet.

ILLUSTRATIONS: E. & P. Nat. Pfl. 22: f. 32; Hitche. Text-book Grasses f. 26; Zeits. Naturw. 79:
pl. 3; Bull. U. S. Dept. Agr. 772: f. 149; Contr. U. S. Nat. Herb. 22: f. 66.

Note: Pennisetum americanum K.Schumann, based on Panicum americanum L,., has been used
for this species, but the Linnaean name is based on two unidentifiable figures.

3. Pennisetum purpureum Schum.; Schum. & Thonn. Beskr.
Guin. Pl. 64. 1827.

Plants perennial in very large clumps; stems suberect, often decumbent at base, 2-2.5
meters tall, robust, glaucous, sparingly branching, densely pubescent below the panicle and
sometimes below the nodes, the nodes glabrous or those of the branches appressed-hirsute;
leaves numerous; leaf-sheaths often pubescent on the collar, otherwise glabrous; ligule stiffly
ciliate, 2~2.5 mm. long; blades flat, with a thick midrib, 10-15 mm. wide, elongate, tuberculate-
pilose on the upper surface toward the base, scabrous to smooth beneath, the margin scabrous;
panicles on the main stems 15-25 cm. long, those of the branches smaller, 12-15 mm. thick,
bronze to purplish, rather dense, the axis terete, densely pubescent; fascicles sessile, ascending
to spreading; bristles several, scabrous, or the inner ciliate, 5-10 mm. long, one commonly
12-15 mm. long; spikelets 2—5 (rarely 1), one sessile, the others pedicellate, lanceolate-acuminate,
4-5 mm. long; first glume wanting; second glume from minute to one third as long as the
spikelet; sterile lemma half to two thirds as long as the fertile lemma, its palea sometimes
developed; fertile lemma subindurate at base, with an attenuate-nerved tip.

TYPE LOCALITY: Guinea.
DISTRIBUTION: Equatorial Africa; cultivated for forage in Central America, the West Indies,
and Brazil; occasionally escaped.

4. Pennisetum orientale triflorum (Nees) Stapf; Hook. f. Fl.
Brit. Ind. 7: 86. 1896.

Pennisetum triflorum Nees; Steud. Syn. Gram. 107. 1854.

Plants perennial, forming tough clumps from knotty crowns; stems erect from an ascending
base, usually 1 meter or more tall, rather robust, simple or sparingly branching, pubescent or
scabrous below the panicle, otherwise glabrous, the nodes appressed-pubescent; leaves
numerous; leaf-sheaths loose, mostly overlapping, ciliate on the margin, otherwise glabrous;
ligule lacerate-ciliate, scarcely 1 mm. long; blades flat, lax, 5-10 mm. wide, elongate, sparsely
hispid on the upper surface, scabrous beneath and sometimes with a few scattered hairs;
panicles 12-20 em. long, about 15—20 mm. thick, loose, at least toward the base, the axis angled,
densely pubescent; fascicles pedicellate, spreading or reflexed; bristles several, plumose except
the upper third, 10-15 mm. long, one as much as 2 cm. long; spikelets 3-5, lanceolate-acuminate,
about 6 mm. long, scaberulous; glumes acuminate, weakly nerved, the first less than half as
long, the second nearly as long as the spikelet; sterile floret staminate, the lemma acuminate,
3-nerved, as long as the fertile, the palea about as long; fertile lemma 5-nerved, scarcely firmer
than the sterile lemma.

TYPE Locaity: Nepal.

DISTRIBUTION: India; introduced in Jamaica.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: f. 64.

Part 4, 1931] POACEAE 335

5. Pennisetum ciliare (L.) Link, Hort. Berol. 1: 213. 1827.

Cenchrus ciliaris 1,. Mant. 302. 1771.
Pennisetum cenchroides Rich. in Pers. Syn. Pl. 1:72. 1805.
Panicum vulpinum Willd. Enum. Hort. Berol. 1031. 1809. Not P. vulpinum L. 1759.

Plants perennial, tufted from a knotty crown; stems geniculate, slender, 1-50 cm. tall,
sometimes taller, sparingly branching, scabrous at least on the uppermost joint; leaf-sheaths
minutely scabrous and usually pilose along the margin; ligule ciliate, about 1 mm. long, some-
times minute; blades flat, 3-5 mm. wide, 2-10 cm. long (longer in plants in moist situations),
scabrous on the upper surface and long-pilose toward the base, glabrous or nearly so beneath;
panicle 2-10 cm. long, the axis angled; fascicles nearly sessile, the outer bristles slender,
scabrous, 1-3 mm. long, the inner plumose and flattened below, 5—8 mm. long; spikelets 1-3,
lanceolate, glabrous, about 5 mm. long, the nerves green; first glume ovate-lanceolate, 1-
nerved, 2 mm. long; second glume 3-nerved, 3 mm. long; sterile lemma 5-nerved, as long as
the fertile floret, the palea about as long; fertile floret only a little firmer than the sterile, the
lemma 5-nerved.

Type LocaLity: Cape of Good Hope.
DISTRIBUTION: India to Africa; introduced in Porto Rico and Guatemala.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: f. 65.

6. Pennisetum Karwinskyi Schrad. Linnaea 12: 431. 1838.

Cenchrus multiflorus Presl, Rel. Haenk. 1: 318. 1830.
Pennisetum multiflorum Fourn. Mex. Pl. Gram. 49. 1886. (This name is not based on Cenchrus
multiflorus Presl.)

Plants perennial, in loose clumps from hard knotted crowns, the stems produced from
hard scaly bulb-like buds which burst through the basal and underground sheaths; stems erect,
simple or with leafy shoots from the lower nodes, mostly 1—-1.5 meters, rarely only about 0.5
meter tall, very scabrous below the panicle, otherwise glabrous, the lower internodes com-
pressed; leaf-sheaths keeled, mostly overlapping, pilose along the margin at least toward the
summit, sometimes sparsely papillose-pilose, or rarely the lower densely pilose, throughout;
ligule 1.5—2 mm. long, membranaceous-ciliate; blades usually rather firm, ascending or spread-
ing, flat, 10-40 cm. long, 5-15 mm. wide, broadest at the base, tapering to a long-attenuate
very scabrous, usually involute tip, the upper surface scabrous and usually sparsely papillose-
pilose, rarely densely so, sometimes scabrous only, the lower surface usually scabrous, some-
times smooth, the margins very scabrous; panicle 5-17 cm. long, mostly 10-12 mm. wide,
excluding the elongate bristles, tawny or purplish or sometimes greenish, mostly dense except
at the base, but sometimes the fascicles rather loosely arranged, the axis strongly angled,
pubescent; fascicles on a short thick densely pubescent pedicel; outer bristles slender, 1-3 mm.
long, scabrous, the inner firm, thickened at base, 5-7 mm. long, often one of them 2 or 3 times
as long as the others, some of the inner plumose; spikelets about 3, lanceolate, 5-6 mm. long,
scaberulous; first glume about half as long as the spikelet, 1-nerved; second glume about two
thirds as long as the spikelet; 5-nerved; sterile and fertile florets similar, 5-nerved, the sterile
floret staminate, the palea nearly as long as the lemma, the fertile floret firmer and more faintly
nerved.

TYPE Locality: Mexico.
DISTRIBUTION: Mexico to Costa Rica.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: f. 67.

7. Pennisetum vulcanicum Chase, Jour. Wash. Acad. 13:
3653). 1923;

Plants perennial, about 1 meter tall; stems suberect, terete and scabrous below the panicle,
otherwise compressed and glabrous, branching from the lower nodes; nodes glabrous; leaves
numerous, the sheaths overlapping, keeled, villous along the margin and on the sides of the
collar, otherwise glabrous or very sparsely pilose; ligule densely ciliate, about 1 mm. long;
blades flat or drying folded, with a prominent midnerve, 20-45 cm. long, 5-8 mm. wide, with
a long scabrous tip, scabrous and papillose-pubescent or papillose only on the upper surface,
glabrous beneath; panicle slightly flexuous, 10-17 cm. long, 18-20 mm. wide, excluding the

336 NORTH AMERICAN FLORA [VOLUME 17

longest bristles, tawny or purplish tinged, rather dense except at the base, the axis pilose on
the angles; fascicles on hairy peduncles 1-1.5 mm. long, finally spreading or reflexed; bristles
numerous, scabrous, united at the very base, very unequal, the outermost short, slender,
scabrous only, the inner 1-1.5 cm. long, flattened, flexuous, plumose about half their length,
the innermost one stouter, 2-5 cm. long, plumose at base, unequal in fascicles of the same
panicle, the longer in the middle fascicles; spikelets 3-5 in each fascicle (only 1 or 2 well de-
veloped), sessile, 6—9 mm. long, about.1.4 mm. wide, attenuate, scaberulous; glumes attenuate,
3-5-nerved, the first one fourth to one third, the second two thirds to three fourths as long
as the spikelet; sterile lemma nearly as long as the fertile, finely many-nerved, inclosing a palea
of nearly equal length and a staminate flower; fertile lemma subindurate, 5-nerved, the apex
attenuate and spreading.

TYPE LocaLity: Salvador.
DtstRrBuTION: Salvador and Costa Rica.

8. Pennisetum setosum (Sw.) Rich. in Pers. Syn. Pl. 1: 72. 1805.

Cenchrus setosus Sw. Prodr. 26. 1788.
Panicum cenchroides Rich. Act. Soc. Hist. Nat. Paris 1: 106. 1792.
Panicum erubescens Willd. Enum. Hort. Berol. 1031. 1809.
Penniselum purpurascens H.B.K. Noy. Gen. & SP TEAS elo.
Pennisetum uniflorum H.B.K. Nov. Gen. & Sp. 1: 114. 1815.

™ Panicum densispica Poir. in Lam. Encyc. Suppl. 4:273. 1816.

\. Panicum triticoides Poir. in lam. eh Suppl. 4: 274. 1816.
Setaria cenchroides R. & S. Syst. Veg. 2: 495. 1817.

“Pennisetum triticoides R. & S. Syst. Veg. Parties viltosilsys
Gymnothrix geniculata Schultes, in R. & S. Syst. Veg. Mant. 2: 284. 1824.

~ Selarta geniculata Sieber; Schultes, in R. & S. Syst. Veg. Mant. 2: 284, assynonym. 1824.
. Pennisetum alo pecuroides Desv.; Hamilt. Prodr. 11. 1825.
Penniselum erubescens Desv.; - Hamilt. Prodr. 11. 1825.
Pennisetum Richardi Kunth, Rév. Gram. 49. 1829.
Pennisetum hirsutum Nees, Agrost. Bras. 284. 1829.
Pennisetum pallidum Nees, Agrost. Bras. 285. 1829.
Pennisetum flavescens Presl, Rel. Haenk. 1: 316. 1830.

~ Pennisetum dasistachyum Desv. Opusc. 76. 1831.
Pennisetum Hamiltonii Steud. Nom. Bot. ed. 2. 2: 297. 1841.
Pennisetum Sieberi Kunth; Steud. Syn. Gram, 109. 1854.
Pennisetum nicaraguense Fourn. Bull. Soc. Bot. Fr. 27: 293. 1881.
Pennisetum indicum var. purpurascens Kuntze, Rev. Gen. 787. 1891.

Plants perennial, in loose clumps, sometimes 30 or more stems in a clump; stems usually
1-2 meters tall, slender to robust, subcompressed, ascending or suberect from the more or
less geniculate, sometimes rooting lower nodes, bearing 1 to several flowering branches from
the lower and middle nodes, scabrous below the panicle, otherwise glabrous; leaf-sheaths
loose, from glabrous to rather densely papillose-hirsute, usually sparsely hirsute along the
margin toward the summit, otherwise glabrous; ligule membranaceous-ciliate, 2-3 mm. long;
blades mostly rather firm, ascending or spreading, 10-40 cm. long, 4-18 mm. wide, tapering
toward the base (or the reduced upper blades widest at base), acuminate into a long slender
very scabrous tip, from scabrous on both surfaces (or rarely glabrous beneath) to rather densely
papillose-hirsute on both surfaces, more commonly scabrous beneath and sparsely papillose-
hirsute above, always stiffly hairy back of the ligule; panicles terminating the primary stem
and branches, occasionally one or two axillary panicles borne in the upper sheaths, 10—25 cm.
long, 8-10 mm. in diameter, excluding the elongate bristles, usually somewhat nodding, rather
dense, from pale-yellow to dusky-purple, the common axis slender and scabrous; fascicles on a
very short pubescent base, spreading or reflexed in age; bristles numerous, the outer slender
and scabrous, the inner stouter, densely silky-plumose below, irregular in length, 3-6 mm.
long, one longer, sometimes as much as 2 cm. long; spikelets solitary, sessile, about 3 mm.
long, scaberulous; first glume oblong, obtuse or acute, nerveless or 1-nerved, less than half as
long as the spikelet; second glume nearly as long as the spikelet, obtuse or acute, 5—7-nerved;
sterile floret staminate, the lemma acute, 5-nerved, the palea nearly as long; fertile floret firm,
smooth, minutely ciliate-fringed at the tip.

TYPE LOCALITY: West Indies.

DISTRIBUTION: Tropical America.

ILLusTRATIONS: Kunth, Rév. Gram. pl. 39; Trin. Ic. pl. 20; Bull. U. S. Dep. Agr. Agrost. 20:
f. 27; Bull. U.S. Dep. Agr. 772: f. 150; Contr. U. S. Nat. Herb. 22: f. 68.

Part 4, 1931] POACEAE 337

9. Pennisetum Antillarum (Poir.) Desv. Opusc. 76. 1831.

Panicum Antillarum Poir. in Lam. Encyc. Suppl. 4: 275. 1816.
Saccharum ? Antillarum R. & S. Syst. Veg. 2: 877. 1817.
Setaria Antillarum Kunth, Rév. Gram. 46. 1829.

Plants probably perennial; stems erect, slender, terete, branching, scabrous below the
panicle, otherwise glabrous; leaf-sheaths pilose, ciliate at the throat; blades narrowly linear,
acuminate, pilose on the upper surface at least toward the base, glabrous beneath; panicle
8-15 cm. long, very slender, acuminate; rather dense, the slender axis minutely scabrous;
fascicles approximate, spreading or somewhat reflexed; bristles few, scabrous, the longer
about as long as the spikelet, one about twice as long; spikelets 2-2.5 mm. long; first glume
small or wanting; second glume broad, thin, as long as the spikelet, broad and more or less
3-toothed at summit, 5-nerved; sterile lemma a little shorter than the second glume, somewhat
erose or 3-toothed at summit, 5-nerved; fertile floret glabrous, terete or fusiform, a little shorter
than the second glume and sterile lemma, the apex minutely ciliate-fimbriate.

TYPE LOCALITY: West Indies.
DISTRIBUTION: Only known from the type specimen.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: f. 69.

10. Pennisetum crinitum (H.B.K.) Spreng. Syst. Veg. 1:
30225 1825"
Gymnothrix crinita H.B.K. Nov. Gen. & Sp. 1: 112. 1815.
Pennisetum Humboldtianum Hemsl. Biol. Centr. Am. Bot. 3: 508. 1885.

Plants perennial, glabrous as a whole; stems solitary or few together, erect from a curved
or slightly geniculate base, robust, usually 2 meters or more tall, commonly bearing leafy
flowering branches from all but the lower nodes, these often bearing sterile branches, the
internodes conspicuously channeled on the side toward the sheath, the lower mostly com-
pressed, relatively short, the upper elongate; leaf-sheaths much shorter than the internodes,
rather loose; ligule stiffly ciliate, about 0.5 mm. long; blades erect or ascending, rather thick,
flat, those of the main culm 20-40 cm. long, 8-18 mm. wide, broadest at the base, those of
the branches smaller; primary panicles usually rather short-exserted, mostly stiffly erect,
12-25 em. long, about 10 mm. thick, excluding the longer bristles, dense or sometimes loose
at the base, stramineous or tawny or sometimes with pale bristles and greenish-purple spikelets,
the axis ridged, scabrous, toward the base often 2 mm. thick, the panicles of the branches
commonly partly included, shorter, more slender, less densely flowered; fascicles nearly sessile;
bristles few, scabrous, not plumose, irregular in length, 3-10 mm. long, the innermost stouter,
1.2-20 mm. long; spikelet solitary, sessile, 5-6 mm. long, scaberulous toward tip; first glume
obtuse, half as long as spikelet, 1-nerved; second glume nearly as long as spikelet, 5-nerved;
sterile lemma acuminate, about as long as the fertile, 5-nerved, fertile lemma acuminate, firm,
obscurely 5-nerved, minutely scaberulous.

TYPE LocALITy: Michoacan, Mexico.

DistRIBuTION: Southern Mexico.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: f. 70.

11. Pennisetum nervosum ‘l'rin. Mém. Acad. St.-Pétersb. VI.
3?:177. 1834.
Gymnothrix nervosa Nees, Agrost. Bras. 277. 1829:

Plants perennial, in large clumps; stems erect from a branching geniculate base, robust,
1.5-3 meters tall, compressed, glabrous, sparingly branching; leaves numerous, the leaf-
sheaths commonly purplish, loose, glabrous; ligule stiffly ciliate, less than 1 mm. long; blades
firm, flat or folded, those of the main culm 15-40 cm. long, 8-15 mm. wide, the upper some-
times reflexed, the upper surface and margin scabrous; panicles mostly short-exserted, 15-30
cm, long, 12-15 mm. thick, dense, tawny to purplish-tinged, flexuous or with an S-shaped
bend in the middle, the slender scabrous axis readily breaking; fascicles sessile; bristles nu-
merous, slender, scabrous, 4-12 mm. long, one not conspicuously longer than the rest; spikelet
solitary, sessile, 5—6 mm. long, acuminate, strongly nerved; first glume about one fourth the

338 NORTH AMERICAN FLORA [VOLUME 17

length of the spikelet; second glume and sterile lemma subequal, attenuate, strongly nerved,
scaberulous; fertile lemma slightly shorter, subindurate, attenuate.

TYPE LOCALITY: Bahia, Brazil. ; ; :
DISTRIBUTION: Southern Texas (Brownsville); Brazil and Ecuador to Argentina.

12. Pennisetum complanatum (Nees) Hemsl. Biol. Centr. Am.
Bot. 3: 507. 1885.

Gymnothrix complanata Nees, Bonplandia 3: 83. 1855.

Gymnothrix mexicana Fourn. Mex. Pl. Gram. 48. 1886.

Gymnothrix Grisebachiana Fourn. Mex. Pl. Gram. 48. 1886.

Pennisetum mexicanum Hemsl.; B. D. Jackson, Ind. Kew. 2: 458. 1894.

Plants perennial; stems solitary or few together, erect or ascending from a strong rhizome,
scabrous below the panicle, otherwise glabrous, simple or, more commonly, with one or two,
rarely with several, flowering branches, the lower nodes sometimes geniculate, the internodes
terete (or the lower slightly compressed) slightly or not at all channeled, not elongate and
naked; leaf-sheaths loose, commonly as long as the internodes or longer, pilose on the margin
at the summit, sometimes pubescent on the collar; ligule ciliate, about 2 mm. long; blades
thinner than in P. crinitum, mostly somewhat spreading, flat, or folded at base, 20-55 cm.
long, 5-8, rarely 10 mm. wide, glabrous beneath, very scabrous on the upper surface, often
papillose-pilose toward the base, and with stiff hairs just back of the ligule, attenuate into an
elongate involute-setaceous tip; panicles nodding or somewhat flexuous, 7-16 cm. long, about
10-12 mm. thick, excluding the longest bristles, with tawny or purplish bristles and pale
spikelets, the slender axis ridged and scabrous; fascicles on a very short pubescent base;
bristles several, scabrous but not plumose, mostly 10-15 mm. long, one as much as 2 cm. long;
spikelets solitary, sessile, ovate-lanceolate, 5-6 mm. long, minutely pubescent above; first
glume triangular, 1-nerved, about one fourth as long as the spikelet; second glume a little
shorter than the spikelet, acuminate or subulate-pointed, 5-nerved; sterile lemma as long as
the fertile, 7-nerved, acuminate, the stamens wanting, the palea 2-toothed, nearly as long as
the lemma; fertile lemma acuminate, scaberulous, weakly 5-nerved, the palea free at the tip.

TYPE LOCALITY: Panama.
DISTRIBUTION: Southern Mexico to Panama.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: f. 71.

13. Pennisetum domingense Spreng. Syst. 1: 302. “1825.
Gymnothrix domingensis Spreng.; Schultes, in R. & S. Syst. Veg. Mant. 2: 284. 1824.

Plants perennial; stems tall, wiry, glabrous, branched, the branches solitary or fascicled,
the internodes elongate, rigid; leaf-sheaths glabrous, striate, more or less inflated; ligule very
short, ciliate; blades rigid, involute, spreading, glabrous, subulate-pointed, 1-5 cm. long, readily
falling from the sheath; panicles 3-6 cm. long, erect, the rachis angled, scabrous; fascicles rather
few, subsessile; bristles numerous, flexuous, scabrous, 5—10 mm. long, one about twice as long;
spikelets 44.5 mm. long; first glume ovate, acute, about one third as long as the spikelet; second
glume oblong-ovate, acute, about twice as long as the first, 5-nerved; sterile lemma as long as
the spikelet, weakly 5-nerved, concave on the back, somewhat mucronate, the palea about as
long as the lemma, inclosing stamens; fertile lemma firm, brownish, mucronate, somewhat
scaberulous.

TYPE LocaLity: Santo Domingo.

DistrR1BpuTIoN: Cuba and Santo Domingo.
ILLusTRaTiIon: Contr. U. S. Nat. Herb. 22: f. 72.

14. Pennisetum durum Beal, Grasses N. Am. 2: 163. 1896.

Pennisetum crinitum Scribn.; Beal, Grasses N. Am. 2: 163. 1896. Not P. crinitum Spreng. 1825.
Pennisetum Pringlei Leeke, Zeits. Naturw. 79:33. 1907.

Plants perennial; stems erect, glabrous, sometimes glaucous, 1-2 meters tall, branched
above, the few branches appressed, the nodes glabrous or puberulent; leaf-sheaths glabrous or
scaberulous; ligule densely ciliate, about 1.5—2 mm. long; blades flat, linear, gradually narrowed

Part 4, 1931] POACEAE 339

into a slender point, as much as 60 cm. long, 5-15 mm. wide, scabrous or pubescent; panicles
terminal and 1-4 from the upper sheaths, on rather slender scabrous peduncles, nodding,
3-10 cm. long, 1 cm. wide, densely flowered, pale-greenish, the axis angled, scabrous; bristles
several, most of them shorter than the spikelets, the innermost sometimes twice as long as the
spikelet; spikelets 6-7 mm. long, acuminate; first glume obtusish, about one fourth as long as
spikelet, nerveless, ciliolate; second glume about half as long as spikelet, obtusish, ciliolate,
sometimes scaberulous, 3—5-nerved; sterile lemma acuminate, as long as spikelet, scaberulous,
5-nerved, concave on the back; fertile lemma acuminate, firm, scaberulous, especially at tip.
TYPE LocaLity: State of Chihuahua, Mexico.

DISTRIBUTION: Chihuahua to Oaxaca.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: f. 73.

15. Pennisetum distachyum (Fourn.) Rupr.; Fourn. Mex. Pl.
Gram. 48. 1886.
Gymnothrix distachya Fourn. Mex. Pl. Gram. 48. 1886.

Plants perennial; stems 1—4 meters tall, robust, glabrous or scabrous below the nodes,
branching from the middle and upper nodes, the primary branches ascending, the secondary
and ultimate branchlets slender and spreading or nodding with 1—4 slender-peduncled drooping
panicles from each sheath, the whole forming a top-heavy, leafy compound inflorescence;
nodes appressed-hirsute; leaf-sheaths loose, hirsute along the margin and at the summit or
glabrate; ligule 2-3 mm. long; blades flat, mostly spreading, appressed-hirsute on both surfaces
or glabrate beneath and sometimes nearly so above, those of the main culm 25-45 cm. long,
1.5-3.5 em. wide, narrowed or attenuate at base, the apex acuminate; panicles numerous, dull
green, the slender, flexuous, scabrous peduncles unequal, the longest often as much as 15-20
em. long, one of the cluster of panicles usually partly included, the panicles rather densely
flowered, 3-8 cm., rarely 10 cm. long, about 1 cm. wide, excluding the longest bristles, usually
tapering to the apex, the axis slender, angled, scabrous; bristles slender, scant (mostly less
than 20) unequal, most of them shorter than the spikelet, or but little exceeding it, the inner-

_ most about twice as long as the spikelet; spikelets 4.5-5.5 mm. long, 1-1.2 mm. wide, acuminate;

glumes unequal, obscurely ciliolate, the first minute, l-nerved, acute or obtuse, the second
about one third to nearly half the length of the spikelet, 3-nerved, acute or subacute; sterile
lemma slightly exceeding the fertile lemma, 5-nerved, depressed down the middle, scabrous
especially toward the summit, acuminate, the palea wanting; fertile lemma acuminate, but
little indurate, 5-nerved and scabrous toward the summit.

TYPE LocaLity: State of Vera Cruz, Mexico.
DISTRIBUTION: Southern Mexico to Costa Rica.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: f. 74.

16. Pennisetum prolificum Chase, Contr. U. S. Nat. Herb. 22:
23. M9217

Plants perennial; resembling P. distachyum, branching from the upper nodes, the branches
often in fascicles of 2 to several, relatively slender, repeatedly fasciculately branching, the
ultimate branchlets very slender, nodding, their nodes often strongly geniculate, the very
numerous panicles 2-5 together on very slender flexuous usually glabrous peduncles, mostly
2-10 cm. long, the terminal panicle often solitary, the whole system of branches forming a
great drooping, leafy compound inflorescence often 1 meter or more long and probably nearly
as wide; nodes glabrous or strigose; leaf-sheaths loose, glabrous or ciliate on the margin above,
sometimes with a few long soft hairs.at the summit; ligule about 2 mm. long; blades on the
average a little shorter and broader than those of P. distachyum, narrowed but not long-
attenuate at base, glabrous on both surfaces or slightly scabrous above; panicles tawny, 3-5
cm. long, about 1 cm. wide, denser than in P. distachyum, slightly tapering or obtuse at the
apex; bristles slender, numerous, more spreading than in P. distachyum, most of them exceeding
the spikelet, the innermost not conspicuously longer than the rest; spikelet similar to that of
P. distachyum, but minutely scabrous only or glabrous, the glumes thinner, more obtuse, the

340 NORTH AMERICAN FLORA [VOLUME 17

first usually nerveless, often erose; sterile palea wanting; fertile lemma thinner than in P.
distachyum.

TYPE LOCALITY: State of Vera Cruz, Mexico.
DISTRIBUTION: Southern Mexico.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: f. 75.

17. Pennisetum bambusiforme (Fourn.) Hemsl.; B. D. Jackson,
Ind. Kew. 2: 458. 1894.

Gymnothrix bambusiformis Fourn. Mex. Pl. Gram. 48. 1886.
Pennisetum tristachyum bambusiforme Leeke, Zeits. Naturw. 79: 33. 1907.
Pennisetum tristachyum Galeottiana Leeke, Zeits. Naturw. 79:33. 1907.

Plants perennial, resembling P. distachyum, glabrous, branching from the upper nodes,
the branches often in fascicles of 2 or 3 (on the average less numerous than in P. prolificum),
slender, repeatedly branching, the whole forming a drooping compound leafy inflorescence,
looser and less massive than in P. prolificum; nodes glabrous, rarely appressed-pubescent;
leaf-sheaths loose, ciliate on the margin and with an erect tuft of white hairs at the summit
(old sheaths commonly glabrescent); ligule about 2 mm. long; blades flat, rather firmer than
in the two preceding species, ascending or spreading, those of the main culm 20-35 cm. long,
2-3.5 cm. wide, narrowed, sometimes somewhat attenuate at base, scabrous or appressed-
pubescent on the upper surface, softly appressed-pubescent beneath, sometimes glabrescent;
panicles purplish-tawny, 5-12 cm. long (rarely longer), about 1 cm. wide, excluding the longest
bristles, loose, flexuous, tapering at the apex, the slender angled axis scabrous or hispidulous;
fascicles not crowded, ascending; bristles slender, flexuous, numerous, very unequal, most of
them about twice the length of the spikelet, the innermost sometimes as much as 2 cm. long;
spikelet 5-6 mm. long, 1—1.2 mm. wide, scabrous; glumes unequal, the first minute, usually
nerveless, obtuse or erose, the second one fourth to one third the length of the spikelet, 1—3-
nerved, acute or erose; sterile lemma exceeding the fertile lemma, 5—7-nerved, attenuate into a
slender flexuous tip, inclosing a well-developed palea and usually a staminate flower; fertile
lemma 4.5—5 mm. long, scabrous toward the acuminate apex, but little indurate.

TYPE LocaLity: Mirador, Vera Cruz.

DISTRIBUTION: Southern Mexico to Peru.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: f.76. *

72. CENCHROPSIS. See 74. Cenchrus (page 341).
73. PARATHERIA Griseb. Cat. Pl. Cub. 236. 1866.

Perennial spreading grasses with short flat blades and spike-like racemes. Spikelets
appressed to slender erect branches, the ends of the branches produced beyond the spikelets as
slender awns, the articulation at the base of spikelet and also of branch, this forming a sharp
callus below the attached acuminate spikelet. Glumes minute or obsolete. Sterile lemma
equaling the cartilaginous fruit.

Type species, Paratheria prostrata Griseb.

1. Paratheria prostrata Griseb. Cat. Pl. Cub. 236. 1866.
Chamaeraphis parvigluma Munro; Sauvy. Anal. Acad. Ci. Habana 8: 208, name only. 1871.
Panicum leptochyrium Doll, in Mart. Fl. Bras. 2?: 150. 1877.

Stems prostrate or decumbent, branching, 50 cm. long, glabrous, the nodes appressed-
hispid; leaf-sheaths hirsute or the upper glabrate; ligule densely ciliate, about 1 mm. long, with
a few longer hairs at the sides; blades rather stiff, spreading or ascending, flat, more or less
villous, scabrous on the margin, acuminate, scarcely narrowed at base, as much as § em. long,
mostly 3-5 cm., 3-4 mm. wide; raceme partly inclosed in the base of the upper sheath, erect,
5-10 cm. long, the axis scabrous, the branches appressed, slender and stiff, angled, scabrous,
the basal part adnate to the axis and tapering to a point, separating at maturity and forming a
scabrous sharp point to the fruit, the upper part tapering into a slender awn 2-3 em. long;
spikelets narrow, flattened, lanceolate-acuminate, 7-9 mm. long, the pedicel about 1 mm.

Parr 4, 1931] POACEAE 341

long; glumes thin, less than 1 mm. long, sometimes obsolete, a few slender hairs at base, the
second glume next to the axis; sterile lemma as long as the spikelet, acuminate, weakly several-
nerved or striate, neuter, the palea wanting; fertile lemma acuminate, cartilaginous, the wide
thin flat margins inclosing the margins of the palea to the tip; palea acuminate and as long
as the lemma, rounded on the back, the two keels appearing as faint nerves.

TYPE LocALITY: Handabana, Cuba.

DISTRIBUTION: Western Cuba; also in Brazil and tropical Africa.
ILLUSTRATION: Mart. Fl. Bras. 2?: pl. 25.

74. CENCHRUS L. Sp. Pl. 1049. 1

Rarum Adans. Fam. Pl. 2: 35,597. 1763.
Cenchropsis Nash, in Small, Fl. SE. U.S. 109, 1327. 1903.

Annual or perennial low or moderately tall, often spreading grasses, with mostly flat leaf-
blades and spicate inflorescence. Spikelets sessile, one to several together, permanently
inclosed in a bristly or spiny involucre or bur, composed of more or less coalesced sterile branch-
lets; burs sessile or nearly so on a slender, compressed cr angled axis, its apex produced into a
short point beyond the uppermost bur, the burs falling entire, the grains germinating within
them; involucre (especially in our species) somewhat oblique, its body irregularly cleft, the
lobes rigid, in most species resembling the spines, the cleft on the side of the bur next to the axis
reaching to the tapering, abruptly narrowed or truncate base, the bristles or spines barbed,
at least toward the summit; spikelets mostly glabrous or nearly so; first glume 1-nerved,
usually narrow, sometimes wanting; second glume and sterile lemma 3- to 5-nerved, the lemma
inclosing a well-developed palea and usually a staminate flower; fruit usually turgid, indurate,
the lemma acuminate, the nerves visible toward thé summit, the margins thin, flat, a prominent
U-shaped ridge on the back just above the base, the radicle at germination breaking through
its outer margin; stamens 3; styles 2, the stigmas plumose; grain dorsally compressed, with a
punctiform hilum, free within the lemma and palea.

Type species, Cenchrus echinatus 1.

~sI

On
Ww

Involucral lobes united at the base only; spikes dense.

Plants perennial; involucral lobes terete, scabrous. 1. C. myosuroides.
Plants annual; inner involucral lobes sulcate down the outside, densely
villous-ciliate within. 2. C. catharticus.

Involucral lobes united above the base.
Blades involute, squarrose, numerous, conspicuously distichous, not more
than 2.5 cm. long, about 1 cm. apart. 3. C. distichophyllus.
Blades not involute and squarrose, nor conspicuously distichous, much
longer and farther apart.
Involucre with a ring of slender bristles at base. Plants annual.
Bristles antrorsely scabrous, much exceeding the involucral lobes. 4. C. pilosus.
Bristles retrorsely barbed, not much exceeding the involucral
lobes.
Burs, excluding the bristles, not more than 4 mm. wide, numer-
ous, crowded in a long spike; lobes of the involucre interlock-
ing, not spine-like. 5. C. viridis.
Burs, excluding the bristles, 5-7 mm. wide, not densely
crowded; lobes of the involucre erect or nearly so or
rarely one or two lobes loosely interlocking, the tips
spine-like.
Spikelets about 5.5 mm. long; involucral lobes villous at
base within. 6. C. echinalus.
Spikelets 6.5 mm. long; involucral lobes long-ciliate except
at summit. 7. C. insularis.
Involucre with flattened spreading spines, no ring of slender bristles
at base.
Body of the bur ovate, not more than 3.5 mm. wide, tapering at
base; plants perennial.

Burs glabrous; spines 4-6 mm. long. 8. C. gracillimus.
Burs pubescent; spines rarely more than 4 mm. long, usually
shorter. ,
Body of bur 3-3.5 mm. wide; spines 3-4 mm. long. 9. C. incertus.
Body of bur less than 3 mm. wide; spines 2-3 mm. long. 10. C. microcephalus.

Body of the bur globose, 5 mm. wide or more, not tapering at base;
plants annual.

Burs, including spines, 7-8 mm. wide, finely pubescent. 11. C. pauciflorus.
Burs, including spines, 10-40 mm. wide, densely woolly. , i
Burs several to many; spines not more than 8 mm. long. 12. C. tribuloides,

Burs 1 to 4; spines 1 cm. long or more. 13. C. Palmeri.

342 NORTH AMERICAN FLORA [VoLUME 17

1. Cenchrus myosuroides H.B.K. Noy. Gen. & Sp. 1: 115. 1815.
1

Panicum cenchroides Ell. Bot. S. C. & Ga. 1: 111. 1816. Not P. cenchroides Rich. 1792.
Pennisetum pungens Nutt. Gen. 1:54. 1818.

Pennisetum myosuroides Spreng. Syst. 1: 303. 1825.

Cenchrus Elliottii Kunth, Rév. Gram. 51. 1829.

Cenchrus alopecuroides Presl, Rel. Haenk. 1: 317. 1830.

Cenchrus setoides Buck. Prel. Rep. Geol. & Agr. Surv. Tex. App.3. 1866.

Cenchropsis myosuroides Nash, in Small, Fl. SE. U. S. 109, 1327. 1903.

Plants perennial, solitary or in small clumps, usually 1-2 meters tall, glabrous as a whole;
stems rather robust and woody, terete, commonly glaucous, erect or geniculate below (rarely
decumbent with ascending flowering branches), commonly branching from the lower 2-5 nodes,
most of the branches sterile, sometimes fascicled, forming conspicuous knobs at the node;
leaf-sheaths loose, usually not clasping the internodes, firm, strongly nerved; ligule 2-3 mm.
long, firm-membranaceous, with a densely ciliate margin; blades ascending or spreading, firm,
15-40 cm. long, 5-12 mm. wide, tapering from the rounded flat base to an attenuate, often
involute tip, scabrous on the upper surface, rarely sparsely pilose at the base; inflorescence
usually short-exserted, 10-25 em. long, 5—9 mm. wide, strict, erect, dense, the common axis
slender, angled, puberulent; burs 1-flowered, at first appressed, spreading in age, 5-7 mm.
(mostly about 5 mm.) long, at maturity about as wide, the bristles retrorsely scabrous, united
at the base only, the lowest row shorter, slender and spreading, the inner bristles slender, not
flattened nor nerved, about equaling the spikelet, erect or nearly so; spikelet 4.5-5.5 mm.
long, 1.5-1.8 mm. wide, acuminate; first glume about one third the length of the spikelet;
second glume and sterile lemma 3- to 5-nerved, the glume slightly shorter than the equal
sterile lemma and fruit.

TYPE LOCALITY: Batabané, Cuba. .
DISTRIBUTION: Georgia to Florida, Texas, and Sonora, south to Oaxaca; Cuba, Porto Rico;

Peru to Argentina.
ILLUSTRATIONS: H.B.K. Nov. Gen. & Sp. pl. 35; Bull. U. S. Dep. Agr. Bot. 12!: pl. 6; Bull.
U.S. Dep. Agr. Agrost. 7: f. 70; Contr. U. S. Nat. Herb. 22: f. 7.

2. Cenchrus catharticus Delile, Ind. Sem. Hort. Monsp. 1838: 4.
1839; Linneea 13: Lit.-Ber. 103. 1839.
Cenchrus niloticus Fig. & De-Not. Mem. Accad. Torino II. 14: 380. 1855.
Cenchrus annularis Anderss. in Peters, Reise Mossamb. Bot. 553. 1864.

Plants annual, glabrous as a whole, decumbent and rooting at the lower nodes, the ends
and the branches ascending; stems 30-100 cm. long, not much compressed, scabrous below
the inflorescence; leaf-sheaths loose, keeled, scabrous at the summit; ligule stiffly ciliate, about
1 mm. long; blades narrowly ascending, 10-20 cm. long, 5—6 mm. wide at the base, tapering
thence to an attenuate involute tip, scabrous on the upper surface, smooth or nearly so beneath;
spikes included at base or short-exserted, 8-10 cm. long, about 7—9 mm. wide, the axis slender,
angled, scabrous; burs usually 2-flowered, nearly erect, 4-6 mm. long, scarcely as wide, the
pedicel almost obsolete; bristles united at the base only, the outer row short, terete, spreading,
unequal, the inner (7-10) flattened, subequal, rigid, erect, the scabrous tips slightly spreading,
the outer surface sulcate down the middle, with 1-3 green nerves in the sulcus, densely villous
along the margin on the inner surface except at the summit; spikelets slightly shorter than
the inner involucral lobes; first glume developed or obsolete; second glume and sterile lemma
thin, faintly 3- to 7-nerved, two thirds to three fourths as long as the fruit, the sterile palea
usually well developed; fruit 4-4.5 mm. long, about 1.5 mm. wide, acuminate.

TYPE LocaLity: Nubia.

DISTRIBUTION: On ballast about Mobile, Alabama; native from Egypt to Abyssinia.
ILLUSTRATIONS: Mem. Accad. Torinto II. 14: pl. 33; Contr. U. S. Nat. Herb. 22: f. 8.

3. Cenchrus distichophyllus Griseb. Cat. Pl. Cub. 234. 1866.

Plants perennial; stems tufted, rigid, erect, or ascending from a curved, not geniculate
base, simple or with a few appressed branches, the numerous internodes very short, the long
leafless upper part of the stem appressed-pubescent; leaf-sheaths overlapping, appressed-
pubescent, often becoming glabrate in age; ligule ciliate, scarcely 1 mm. long; blades 1.5—2.5

Part 4, 1931] POACEAE 343

em. long, about 1.5 mm. wide, conspicuously distichous, stiffly spreading at a uniform angle
and usually about 1 cm. apart, involute, sharp-pointed, glabrous on the outer surface, scabrous
on the inner, sometimes with a few long hairs at the base; spike long-exserted, 2-3 cm. long,
bearing usually 5—7 spreading yellow burs, the slender axis glabrous, its summit prolonged
beyond the uppermost bur as a sharp point 2-4 mm. long; burs, including the spines, 5-6 mm.
long, nearly as broad, the body of the bur about 3 mm. long and 2 mm. wide, puberulent, the
outer spines subterete, swollen at the base, the lobes of the involucre about 10, prolonged into
sharp, slender spines, pilose on the inner surface toward the base, retrorsely barbed toward
the tip; spikelet solitary, terete or thicker than wide, about 3.3 mm. long and 1.3 mm. wide;
first glume very narrow, often obsolete; second glume obtuse, shorter than the subequal pointed
sterile and fertile lemmas; fruit turgid, the palea puberulent on the upper half.
‘TYPE LocaLity: Guanes, Cuba.

DISTRIBUTION: Western Cuba.
ILLUSTRATION: Contr. U. S. Nat. Herb. 22: f. 9.

4. Cenchrus pilosus H.B.K. Nov. Gen. & Sp. 1: 116. 1815.
Cenchrus pallidus Fourn. Mex. Pl. Gram. 50. 1886.

Plants annual; stems often rather stout, compressed, usually decumbent at base and
rooting at the lower nodes, 20-100 cm. long, simple or sparingly branching below, scabrous
below the inflorescence, otherwise glabrous; leaf-sheaths keeled, loose, glabrous or toward
the summit scabrous, or rarely ciliate; ligule ciliate, about 0.8 mm. long; blades 10—40 cm. long,
or rarely longer, 6-12 mm. wide, rather thin and lax, flat or folded at the rounded base, scabrous
on the upper surface and usually pilose, glabrous on the lower surface or scabrous toward the
summit; spikes finally rather long-exserted, 5—14 cm. long, dense or loose at the base, the axis
strongly angled, scabrous, a tuft of white hairs usually borne just below the burs, the summit
prolonged beyond the uppermost bur into a slender point 2-3 mm. long; burs globose, the
body about 5 mm. high, as broad or broader, densely villous, tawny, the numerous slender
bristles antrorsely scabrous, commonly purplish, the inner more than twice as long as the body,
the lobes of the body about 8, interlocking at maturity; spikelets usually 3, exceeding the body
of the involucre, +-4.5 mm. long, about 1.8 mm. wide, acuminate; first glume obsolete; second
glume and sterile lemma shorter than the fruit, thin, very minutely puberulent; fruit turgid,
the palea minutely puberulent between the nerves except toward the base.

TYPE LOCALITY: Near Villa del Pao, Venezuela.

DISTRIBUTION: Southern Mexico to Venezuela and Ecuador.

IL_ustrations: H.B.K. Nov. Gen. & Sp. pl. 36; Contr. U.S. Nat. Herb. 22: f. 10; Field Mus.
Publ. Bot. 7: 40.

5. Cenchrus viridis Spreng. Syst. 1: 301. 1825.

Cenchrus echinatus viridis Spreng.; Griseb. Fl. Brit. W. Ind. 556. 1864.
?Cenchrus viridis macrocephalus DOll, in Mart. Fl. Bras. 2*: 310. 1877.
?Cenchrus rigidus Willd.; D6ll, in Mart. Fl. Bras. 2?:310. 1877.

Plants annual; stems often rather robust, 30-100 cm. tall or more, usually terete, erect
from a more or less geniculate base, the lower internodes commonly short, sparingly branching
from the base or lower nodes, glabrous, or scabrous below the spike only; leaf-sheaths mostly
overlapping, loose, keeled, glabrous; ligule ciliate, scarcely 1 mm. long; blades thin, flat, lax,
mostly 10-30 cm. long, 6-12 mm. wide, rounded at the base, scabrous on the upper surface,
on the margins, and on the midnerve beneath; spike usually short-exserted, 4-10 cm. long,
rarely longer, dense, the slender axis minutely pubescent, the naked tip 2-4 mm. long; burs
depressed-globose, the body about 4 mm. high, as broad or broader, villous, tawny, the outer
bristles numerous, very slender, crowded toward the base, the inner usually exceeding the body
and the spikelets, erect or spreading, the lobes of the body usually 6-8, interlocking at maturity;
spikelets usually 3, exceeding the body of the involucre, mostly 4—4.5 mm. long, about 1.4 mm.
wide; first glume obsolete; second glume two thirds to three fourths as long as the subequal
sterile lemma and fruit.

Type LocALiIty: Guadeloupe, West Indies. eb,

DISTRIBUTION: South Florida, Mexico, and the West Indies to Brazil; also in the Philippine
Islands, Guam, Siam, and northern Australia,

ILLustRaTiIons: Contr. U.S. Nat. Herb. 22: f. 11; Field Mus. Publ. Bot. 7: 40.

344 NORTH AMERICAN FLORA [VOLUME 17

6. Cenchrus echinatus L. Sp. Pl. 1050. 1753.

Cenchrus pungens H.B.K. Nov. Gen. & Sp. 1: 115. 1815.

Cenchrus macrocarpus Ledeb.; Steud. Nom. Bot. ed. 2.1: 317. 1840.

Cenchrus brevisetus Fourn. Mex. Pl. Gram. 50. 1886.

Cenchrus echinatus brevisetus Scribn. in Millsp. Field Mus. Publ. Bot. 2: 26. 1900.

Plants annual; stems ascending from a geniculate or decumbent base, often rooting at
the lower nodes, branching from the base and usually from the lower nodes, commonly 25—
60 cm. long, sometimes as much as 1 meter long, compressed, scabrous below the spike, other-
wise glabrous; leaf-sheaths loose, mostly compressed, glabrous or hairy on the margin toward
the summit, rarely sparsely pilose; ligule ciliate, about 1 mm. long; blades commonly 6-20 cm.
long and 3-8 mm. wide (extremes larger or smaller), usually rather stiff, but sometimes lax,
flat, tapering from the rounded base to a more or less involute or folded summit, glabrous
beneath, scabrous and sparsely pilose on the upper surface, at least toward the base; spikes
finally rather long-exserted, 3-10 cm. long (commonly not more than 7 cm. long), not very dense,
the axis strongly flexuous, scabrous; burs truncate at base, the body 4-7 mm. high, as broad
or broader, pubescent, tawny or plumbeous, the outer slender bristles on the average less
numerous and relatively shorter than in C. viridis, the inner stout, broadened at base, the
longest of them usually about equaling the lobes of the body but sometimes longer or sometimes
much reduced, ascending or spreading, the lobes of the body commonly 10, erect or bent
inward or sometimes one or two lobes inflexed, often with one or two green lines down the back,
the tips hard and spine-like, retrorsely barbed; spikelets 3-6, usually 4, about equaling the lobes
or shorter, 4.5-6 mm. long, about one third as wide; first glume narrow, 1-nerved; second glume
two thirds to three fourths as long as the subequal sterile lemma and fruit, the summit of the
fertile lemma submembranaceous, the 3 nerves usually obvious.

TYPE LOCALITY: Jamaica.

DISTRIBUTION: South Carolina to New Mexico, and southward to Uruguay; introduced in the
Hawaiian Islands, Philippine Islands, and Samoa.

ILLUSTRATIONS: Bull. U.S. Dep. Agr. Agrost. 17: f. 407; Mart. Fl. Bras. 2?: pl. 43; Contr. U.S.
Nat. Herb. 22: f. 12; Field Mus. Publ. Bot. 7: 41 (2 f., 1 as C. brevisetus).

7. Cenchrus insularis Scribn. in Millsp. Field Mus. Publ. Bot. 2:
26. 1900.

Plants annual, resembling robust specimens of C. echinatus, the rather firm blades scabrous
on the upper surface, not pilose; spikes 5-10 cm. long, not very dense, the axis as in C. echinatus;
burs globose, the body 9-11 cm. high, minutely pubescent, the obconical base villous; bristles
very numerous, ascending, the outermost very slender, short, the inner successively broader
at base and longer, two rather well-defined series equaling or exceeding the lobes of the body,
conspicuously long-ciliate at the broad base; lobes of the body 8-10, suberect, exceeding the
spikelets, conspicuously long-ciliate except at the sharp spine-like summits; spikelets 2 or 3,
6-7 mm. long, 2—2.2 mm. wide; first glume narrow, usually obsolete; second glume very minutely
puberulent down the center or glabrous, two thirds to three fourths as long as the equal sterile
lemma and fruit, the base of the sterile lemma and upper part of the palea minutely puberulent,
the summit of the fertile lemma submembranaceous, strongly nerved.

TypE Locattty: Alacran Shoals near Yucat4n.
DISTRIBUTION: Yucatan; also in Colombia.
InLustraTions: Contr. U.S. Nat. Herb. 22: f. 13; Field Mus. Publ. Bot. 7: 42, 43.

8. Cenchrus gracillimus Nash, Bull. Torrey Club 22: 299. 1895.

Plants perennial, at length forming dense clumps, glabrous as a whole; stems 20-80 cm.
tall, commonly branching from the lower nodes, but sometimes remaining simple, often
scabrous toward the summit, compressed, slender, wiry, erect or ascending, the outer culms of
large clumps geniculate at base; leaf-sheaths loose, keeled, the lower overlapping, sometimes
sparsely pilose; ligule ciliate, about 0.5 mm. long; blades usually folded and stiffly flexuous,
5-20 em. long, 2-5 mm. (usually 2-3 mm.) wide, scabrous on the upper surface and sometimes
pilose at the base; spikes usually long-exserted, 2-6 cm. long, the burs not crowded, sometimes
distant more than their own length, the slender axis flexuous, scabrous; burs 3.5—5 mm. wide

Part 4, 1931] POACEAE 345

(excluding the spines), somewhat tapering to the base, glabrous; spines spreading or reflexed,
all glabrous and flat, broadened at base, the lowest ones slender, shorter, some of the upper
ones commonly 5—6 mm. long; body of the bur usually with 1 or 2 deep clefts, the lobes about
8, erect or spreading, 6-8 mm. long, ciliate at the base, rigid and spine-like; spikelets 2 or 3,
5.5-7 mm. long, about 1.5 mm. wide; first glume narrow, usually present; second glume and
sterile lemma attenuate-pointed, the tips often spreading, the glume about three fourths the
length of the attenuate-pointed fruit.

TYPE LocaLity: Eustis, Florida.
DISTRIBUTION: Southern Alabama to Florida, Cuba, Jamaica.
ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost. 17: f. 404; Contr. U.S. Nat. Herb. 22: f. 14.

9. Cenchrus incertus M. A. Curt. Bost. Jour. Nat. Hist. 1:
sisy, Aliskeste
Cenchrus strictus Chapm. Bot. Gaz. 3: 20. 1878.

Plants perennial but apparently fruiting the first year, at length forming dense clumps,
glabrous as a whole; stems 25 to 100 cm. tall, compressed, on the average stouter than those of
C. gracillimus, scabrous (or rarely pubescent) at the summit, ascending or erect from a de-
cumbent base, freely branching; leaf-sheaths loose and open, overlapping on the short lower
internodes, often pilose near the margin toward the summit; ligule ciliate, about 0.5 mm. long;
blades commonly folded, but sometimes flat, rarely stiffly flexuous as in C. gracillimus, 7-25 em.
long, 2-5 mm. (rarely 7 mm.) wide, scabrous on the upper surface and sparsely long-pilose, at
least toward the base; spikes lang-exserted or those of the branches short-exserted, 4-10 cm.
long, the burs not crowded but on the average closer than in C. gracillimus, the slender axis
flexuous, scabrous, sometimes pilose; burs 3-5 mm. wide, excluding the spines, the body finely
and densely pubescent, the base glabrous; spines spreading, flat, broadened at base, the lower
often obsolete on the outer face of the bur and represented by low knobs or ridges, the upper
few, rarely more than 5 mm. long; body of the bur usually not deeply cleft on the outer face,
the lobes commonly 5-7, erect to spreading, 4-6 mm. long, rigid and spine-like, long-ciliate
at the broad base; spikelets 1-3, 5-6 mm. long, about 2 mm. wide; first glume usually present,
narrow, pointed; second glume about three fourths the length of the subequal sterile and fertile
lemmas; fruit attenuate, the palea minutely puberulent toward the summit.

TYPE LocaLity: Near Wilmington, North Carolina.

DistrRIBuTION: North Carolina to Florida and Texas.
ILLUSTRATIONS: Bull. U.S. Dep. Agr. Agrost. 17: f. 405; Contr. U.S. Nat. Herb. 22: f. 15.

10. Cenchrus microcephalus Nash; Hitche. & Chase, Contr. U. S.
Nat. Herb. 18: 356. 1917.

Plants probably perennial, tufted, with numerous leafy sterile shoots at the base, glabrous
as a whole; stems 30-70 cm. tall, compressed, slender, scabrous below the spike, ascending from
a decumbent base, branching from the middle and upper nodes; leaf-sheaths, especially those
of the sterile shoots, strongly keeled, pilose on the margin toward the summit and on the shoots,
with a tuft of white hairs on each side at the apex, this inconspicuous on the old leaf-sheaths;
ligule ciliate, about 0.5 mm. long; blades folded at base, often flat above, rather thin, mostly
10-20 cm. long, 2-3 mm. wide, pilose on the upper surface; spikes mostly short-exserted,
3-5 cm. long, the slender axis flexuous, scabrous; burs (including the bristles) about 6 mm.
long and 5 mm. wide, the body scarcely wider than the thick base, minutely pubescent; spines
flat, broadened at base, the lowermost short and spreading, the upper stout, ciliate at the base,
shorter than the 5 or 6 lobes of the involucre, these erect or ascending, ciliate nearly to the
summit, rigid but relatively blunt; spikelets usually 2, 4-4.5 mm. long, about 1 mm. wide;
first glume nearly half the length of the equal sterile lemma and fruit.

Type Locauity: Berry Islands, Bahamas.

Distrisution: Berry Islands.
ILLUSTRATION: Contr. U.S. Nat. Herb. 22: /f. 16.

346 NORTH AMERICAN FLORA [VoLUME 17

11. Cenchrus pauciflorus Benth. Bot. Voy. Sulph. 56. 1844.

Cenchrus roseus Fourn. Mex. Pl. Gram. 50. 1886.
Cenchrus echinatus {. longispina Hack.; Kneucker, Allg. Bot. Zeits. 9: 169. 1903.

Plants annual, sometimes forming large mats; stems 20-90 cm. long, compressed, rather
stout, scabrous or rarely pubescent at the summit, spreading, ascending or rarely suberect,
from a decumbent base, usually freely branching; leaf-sheaths pubescent along the margin,
rarely throughout, sometimes with a tuft of white hairs at the summit, loose, those below
the spikes commonly inflated; ligule ciliate, nearly 1 mm. long; blades usually flat but some-
times subinvolute or folded, spreading, 3-15 cm. long, 2-7 mm. wide, tapering from base to
apex, scabrous on the upper surface and sometimes on the lower, often pilose near the base
above; spikes numerous, short-exserted or partly included, 1-10 cm. long (commonly 3-8 cm.
long), the burs rather crowded, the slender axis flexuous, scabrous, sometimes pilose; burs
(excluding the spines) 3—7 mm. wide (commonly 4-6 mm.), pubescent, often densely so, rarely
nearly glabrous; spines numerous, spreading or reflexed, flat, broadened at base, the lowermost
shorter and relatively slender, some of the upper ones commonly 4-5 mm. long, usually villous
at the base; body of the bur often with one deep cleft on the outer face, the lobes commonly
about eight, erect or spreading or one or two inflexed, usually villous at the base, rigid and
spine-like; spikelets commonly two, 5—7 mm. long, about 2 mm. wide; first glume usually not
more than one third the length of the spikelet; second glume and sterile lemma subequal or the
lemma nearly as long as the turgid acuminate-pointed fruit.

TYPE LocaLity: Bay of Magdalena, Lower California.

DISTRIBUTION: Maine to Oregon, and southward to Florida, California, and tropical America.

ILLUSTRATIONS: Bull. U. S. Dep. Agr. Bot. 12): pl. 7; Bull. U. S. Dep. Agr. Agrost. 7: f. 69
(as C. tribuloides); Tenn. Agr. Exp. Sta. Bull. 7: pl. 17, f. 65 (as C. tribuloides); Hitche. Text-book
Grasses f. 27 (as C. carolinianus); Britt. & Brown, Ill. Fl. f. 284 (as C. tribuloides); ed. 2. f. 397 (as
C. carolinianus); Contr. U.S. Nat. Herb. 22: /. 17, 18; Field Mus. Publ. Bot. 7: 45 (as C. tribuloides).

Norte: This species was commonly known as C. tribuloides until 1908, and more recently as
C. carolinianus.

12. Cenchrus tribuloides L. Sp. Pl. 1050. 1753.

Cenchrus echinatus tribuloides Torr. F1. U.S. 69. 1823.

Cenchrus vaginatus Steud. Syn. Gram. 110. 1854.

Cenchrus tribuloides macrocarpus Steud. Syn. Gram. 110. 1854.

Cenchrus tribuloides macrocephalus DOll, in Mart. Fl. Bras. 27: 312. 1877.
Cenchrus macrocephalus Scribn. Bull. U.S. Dep. Agr. Agrost. 17: 110. 1899.

Plants annual, very leafy; stems stout, at first erect, soon branching and becoming radiate-
decumbent, 15-60 cm. long, the ends ascending, rooting at the nodes and with numerous
ascending branches 10-30 cm. tall, scabrous or pilose at the summit; leaf-sheaths usually
much overlapping, sharply keeled, broad, those below the spikes inflated, pubescent at least
along the margin and with a dense tuft of hairs on each side at the summit; ligule ciliate, 1 mm.
long; blades flat or folded, the margins usually more or less involute, firm, spreading, 3-18 cm.
long (seldom more than 12 cm. long), 4-7 mm. wide, tapering from base to apex, scabrous on the
upper surface; spikes numerous, usually exceeded by the subtending leaf, 3-9 cm. long, the
burs crowded, the axis flexuous, scabrous or pilose; burs more oblique than in any other of our
species, 5-6 mm. wide and 8-9 mm. high (excluding the spines), usually conspicuously villous,
but sometimes short-pubescent only, the base puberulent, usually with a few long hairs at the
very base; spines finally spreading, flat, the lowermost relatively short and slender, the upper
ones broadened at the base, sometimes as much as 3 mm. broad, some of them 5-8 cm. long,
long-villous on the inner face and margins of the broad base, the hairs of the margin rather
stiffly spreading, the ends needle-like and retrorsely barbed; body of the bur with no deep
cleft on the outer face, the tips of the spikelets usually not showing above the base of the clefts,
the lobes six to eight, mostly about equal and simulating the larger spines, erect to spreading,
villous on the inner face and on the margins at the base like the spines, the outer surface glabrous
or nearly so above the base; spikelets usually two, 7-8 mm. long, about 3 mm. wide; first glume
about one third the length of the spikelet; second glume sometimes minutely puberulent on
the lower part of the middle internerves, slightly shorter than the sterile lemma, this slightly
shorter than the acuminate-pointed fruit.

Part 4, 1931] POACEAE 347

TYPE LOCALITY: Virginia.

DisTRIBUTION: Along the coast, New York to Florida and Louisiana; Costa Rica; West Indies;
also in Brazil.

ILLUSTRATIONS: Bull. U.S. Dep. Agr. Agrost. 17: f. 400; A. Gray, Man. ed. 6. pl. 14; Britt. &
Brown, Ill. Fl. ed. 2. f. 396; Contr. U.S. Nat. Herb. 22: f. 19; Bull. U.S. Dep. Agr. 772: f. 151.

13. Cenchrus Palmeri Vasey; Brand. Proc. Calif. Acad. II. 2:
PANS — altsyexe)-

Plants annual, leafy; stems rather slender, compressed, scabrous below the nodes, pubes-
cent at the summit, at first erect, soon branching and spreading, 12—42 cm. tall; leaf-sheaths
mostly overlapping, loose, retrorsely velvety-pubescent, the hairs longer and denser at the
summit; ligule ciliate, 2-2.5 mm. long; blades mostly flat, rather firm, ascending or spreading,
3-18 cm. long, 3-7 mm. wide, tapering from the base to an attenuate apex, very scabrous on
both surfaces; spikes reduced to 1-4 burs, commonly 1 or 2, the terminal spikes mostly long-
exserted, those of the branches overtopped by the subtending leaf; burs (including the spines)
2-2.5 cm. high and 2.5—4 cm. broad, the body scarcely oblique, depressed-globose, truncate
at base, about 10 mm. high and 12 mm. wide, pale-tawny-canescent ; spines numerous, spreading
or reflexed, usually blackish purple above the villous-canescent, greatly thickened base, but
sometimes yellow, the lowermost short, stout, and thorn-like, the others long-attenuate, re-
trorsely barbed and sometimes flexuous at the needle-like tips, commonly some of them divided
in two part way or to the base, and some 12-15 mm. long; body of the bur thick-walled, the
lobes mostly 12-15, erect or spreading, similar to the spines; spikelets 4-7, more or less distorted
by the pressure of the rigid involucre, 7-9 mm. long, 2-3 mm. wide; first glume very narrow,
usually wanting; second glume and sterile lemma slightly shorter than the acuminate fruit,
obscurely puberulent on the middle internerves.

TYPE LocaLity: Guaymas, Mexico.
DisTRIBUTION: Sonora and Lower California.
ILLustTRATIONS: Bull. U.S. Dep. Agr. Bot. 13!: pl. 3; Contr. U.S. Nat. Herb. 22: f. 20.

DOUBTFUL SPECIES

Cenchrus carolinianus Walt. Fl. Carol. 79. 1788.
Cenchrus gracilis Beauv. Agrost. 57, 157. 1812.
Cenchrus hirsutus Spreng. Neue Entd. 3:15. 1822.

75. STENOTAPHRUM ‘Trin. Fund. Agrost. 175. 1820.

Creeping stoloniferous perennials, with short flowering stems, rather broad and short
obtuse blades, and terminal and axillary spikes. Spikelets imbedded in one side of an enlarged
and flattened corky rachis disarticulating at maturity, the spikelets remaining attached;
first glume small; second glume and sterile lemma about equal, the latter with a palea or
staminate flower; fertile lemma chartaceous.

Type species, Panicum dimidiatum L.

1. Stenotaphrum secundatum (Walt.) Kuntze, Rev. Gen.
794. 1891.

Ischaemum secundatum Walt. Fl. Car. 249. 1788.

Roltboellia stolonifera Poir. in Lam. Encyc. 6: 310. 1804.

Stenotaphrum americanum Schrank, Fl. Monae. pl. 98. 1812.

Stenotaphrum sarmentosum Nees, Agrost. Bras. 93. 1829.

Stenotaphrum glabrum americanum DOll, in Mart. Fl. Bras. 2?: 300. 1877.

“epee te dimidialum americanum Hack.; Stuck. Anal. Mus. Nac. Buenos Aires III. 14: 57.

An extensively creeping glabrous perennial, the stolons with long internodes and short
leafy branches, the sheaths equitant, the blades short, obtuse; flowering stems 10-30 cm. tall,
compressed; leaf-sheaths compressed-keeled, glabrous on the margin; ligule densely pubescent,
scarcely 0.5 mm. long, a few longer hairs at the sides; blades oblong or linear, abruptly rounded
at base and apex, flat or often folded, 2-15 cm. long, usually less than 10 cm., 4-8 mm. wide;

348 NORTH AMERICAN FLORA [VoLUME 17

spikes flat, often falcate, 5-10 cm. long, the rachis 4-5 mm. wide; spikelets partially imbedded
in 2 rows on one side of the rachis, lanceolate, 4-5 mm. long, glabrous or minutely puberulous,
sometimes a few short hairs at the base of the cavity in the rachis and at the base of the first
glume; first glume orbicular, thin, nerveless, sometimes puberulent under a lens, 1 mm. long;
second glume as long as the spikelet, about 7-nerved, rather firm; sterile lemma as long as the
second glume, nearly as firm as the fertile floret, nerveless; fertile lemma cartilaginous, nearly
as long as the second glume.

Typrk LocaLity: South Carolina.

DISTRIBUTION: South Carolina to Louisiana, and southward to Panama and Brazil.

ILLUSTRATIONS: Bull. U. S. Dep. Agr. 772: f. 132; Field Mus. Publ. Bot. 3: 45; Bull. U. S.
Dep. Agr. Bot. 12!: pl. 8; Bull. U. S. Dep. Agr. Agrost. 20: f. 28; Mart. Fl. Bras. 2: pl. 39.

76. AMPHICARPON Raf. Am. Mo. Mag. 2: 175. 1818.

Annual or perennial erect grasses with flat blades and narrow terminal panicles. Spikelets
of two kinds on the same plant, one in a terminal panicle, perfect but usually not fruitful, the
other cleistogamous on slender leafless subterranean branches from the base of the stem or
sometimes also from the lower nodes; first glume of the aerial spikelets variable in size, some-
times obsolete; second glume and sterile lemma about equal; lemma and palea indurate, the
margins of the lemma thin and flat; fruiting spikelets much larger, the first glume wanting;
second glume and sterile lemma strongly nerved, subrigid, exceeded at maturity by the turgid,
elliptic, acuminate fruit with strongly indurate lemma and palea, the margins of the lemma
thin and flat; stamens with small anthers on short filaments.

Type species, Miliwm amphicarpon Pursh.

Blades conspicuously hispid. 1. A. Purshit.
Blades glabrous or nearly so. 2. A. floridanum.

1. Amphicarpon Purshii Kunth, Rév. Gram. 1: 28. 1829.

Milium amphicarpon Pursh, Fl. Am. Sept. 1:62. 1814.
Milium ciliatum Muhl. Descr. Gram. 77. 1817. Not M. ciliatum Moench, 1802.
Amphicarpon amphicarpon Nash, Mem. Torrey Club 5: 352. 1894.

Erect annual; stems glabrous, 30-60 cm. tall; leaf-sheaths overlapping on the lower half
of the culm, papillose-hispid, the uppermost longer; ligule densely ciliate, 1-2 mm. long; blades
stiffly ascending, gradually narrowed from near the base to a stiff somewhat involute point,
densely papillose-hispid, ciliate, 5-15 cm. long, as much as 15 mm. wide, the uppermost reduced
and somewhat distant; terminal panicle 5-15 cm. long, the few branches appressed, or some-
what spreading in anthesis, the lowermost as much as 5 cm. long, the axis and angled branches
very scabrous; spikelets elliptic-lanceolate, glabrous, about 4 mm. long and 1 mm. wide, pale
or yellowish, appressed to the branches, the pedicels hispid-scabrous; first glume small or
wanting; second glume and sterile lemma similar, as long as the spikelet or the sterile lemma a
little longer, 5-nerved, the sterile floret neuter, the palea wanting; fertile floret about as long
as the second glume, cartilaginous, brownish, elliptic-lanceolate, acute, the flat margins of
the lemma with a few appressed hairs, inclosing the palea to the tip; subterranean spikelets on
slender branches reflexed or descending from the base of the culms, the branches bearing
papery scales near the base and usually a single spikelet on a leafless terminal peduncle, the
branches as much as 15 cm. long, usually 5-10 cm.; spikelets fusiform, turgid at maturity,
about 7 mm. long, acute, more or less appressed-hispidulous; first glume wanting; second glume
and sterile lemma about equal, striately several-nerved; fertile lemma indurate, as long as
the sterile lemma, rounded on the back, appressed-hispidulous toward the summit, the apex
acuminate, awl-shaped, hard and sharp.

TYPE LocaLity: Egg Harbor, New Jersey.

DISTRIBUTION: New Jersey to Georgia.

ILLUSTRATIONS: Pursh, Fl. Am. Sept. pl. 2; Bull. U.S. Dep. Agr. Agrost. 7: f. 32; Britt. & Brown,
Ill. Fl. f. 238; ed. 2. f. 389; Bull. U.S. Dep. Agr. 772: f. 152.

Part 4, 1931] POACEAE 349

2. Amphicarpon floridanum Chapm. FI. S. U. S. 572. 1860.

An erect perennial with extensively creeping and branching scaly rhizomes; stems glabrous,
30-60 cm. tall, the nodes glabrous or hispidulous; leaf-sheaths papillose-pubescent, especially
near summit, the lower overlapping, the upper shorter than the internodes; ligule densely
ciliate, about 1 mm. long; blades appressed or ascending, sometimes spreading, oblong-
lanceolate, rounded or partly clasping at the base, acute at apex, rather firm and stiff, glabrous
or sometimes sparingly appressed-hispidulous, the margin thick and cartilaginous, sharply
hispidulous-scabrous; 5-10 cm. long, 4-10 mm. wide, the uppermost somewhat reduced;
panicle 5-15 cm. long, the few distant branches appressed, or in anthesis spreading, the lower-
most as much as 6 cm. long, the axis scabrous; spikelets narrowly elliptic, about 6 mm. long,
acute, glabrous, the angular pedicels hispid-scabrous; first glume small and nerveless or wanting;
second glume and sterile lemma similar, as long as the spikelet, 7-nerved, one or two nerves
sometimes faint, the sterile floret neuter, the palea wanting; fertile floret glabrous, as long as
the second glume, acute; subterranean spikelets borne on branches from the base of the culms or
from the rhizomes, the branches scaly at base with a naked peduncle bearing a single spikelet;
spikelet glabrous, 8-10 mm. long, fusiform, at maturity turgid, the fruit spreading apart the
glume and sterile lemma; first glume wanting; second glume and sterile lemma firm, equal, as
long as the spikelet, several-nerved; fertile floret brownish, turgid-fusiform, subulate-pointed,
the palea rounded and turgid from the inclosed caryopsis; caryopsis subspheric, 5 mm. long,
4.5 mm. wide, with a pubescent apiculate apex.

Type Locatity: Apalachicola River, Florida.

DIstTRIBuTION: South Carolina to Florida.
ILLUSTRATION: Bull. U.S. Dep. Agr. Agrost. 7: f. 33.

77. OLYRA L,. Syst. Nat. ed. 10. 1261. 1759.

Mapira Adans. Fam. Pl. 2:39. 1763.

Woody climbing or straggling perennials with ample blades abruptly narrowed into a
petiole, convolute in the bud before expanding, the consequent creases permanent and con-
spicuous in the mature blades. Spikelets unisexual, unlike in appearance, the staminate and
pistillate together in panicles terminating the culm or leafy branches, the pistillate spikelets on
clavate pedicels on the upper panicle branches or at the ends of the branches, the staminate
spikelets on slender pedicels or subsessile on the lower branches or on the lower part of the
pistillate branches; pistillate spikelets ovate-lanceolate, usually setaceous-pointed; first glume
wanting; second glume and sterile lemma membranaceous, nerved, acuminate-setaceous or
long-acuminate, the glume longer-pointed than the lemma; fruit elliptic, lemma and palea
thick, bony-indurated at maturity, the margins of the lemma scarcely inrolled; grain dorsally
subcompressed, inclosed in the lemma and palea; staminate spikelets readily deciduous, much
smaller than the pistillate, narrowly lanceolate, glumes and sterile lemma wanting, lemma and
palea thin-membranaceous, the lemma 3-nerved, the palea 2-nerved.

Type species, Olyra latifolia L.

Fruit pitted. 1. O. Standleyi.
Fruit not pitted.
Fruit silky-pubescent at base and margins. 2. O. yucatana.

Fruit smooth and glabrous.
Panicles, at least the primary, much more than 10 cm. long, many-flowered;
pistillate spikelets more than 3 mm. long.
Fruit about 10 mm. long.
Fruit 5-6 mm. long.
Blades rounded or subcordate at the asymmetric base.
Blades cordate at the symmetric base.
Panicles ovoid, few-flowered, less than 3 cm. long; pistillate spikelets less
than 3 mm. long.

. O. caudata.

. O. latifolia.
. O. cordifolia,

a nF WwW

. O. lateralis.

1. Olyra Standleyi Hitche. Proc. Biol. Soc. Wash. 40: 86. 1927.

Erect cespitose perennial; stems slender, 1-3 meters tall, the nodes in dry specimens
presenting one or two raised dark sharp edges, sometimes hirsutulous on these ridges; ligule
shorter than the somewhat flaring border at top of leaf-sheath; blades oblong-elliptic, as

350 NORTH AMERICAN FLORA [VoLuME 17

much as 17 cm. long and 4 cm. wide (the lower not seen), somewhat cordate at base, puberulent
on the upper surface at base and on the short petiole; panicle of several fastigiate branches
spreading at maturity, the axis extending above the whorl and bearing one or two ascending
branches, the main branches 8-12 cm. long, bearing appressed spikelets, 1—4 pistillate spikelets
on the upper part, staminate spikelets below, the peduncle and base of the branches more or
less puberulent, smaller axillary panicles from the upper sheaths; staminate spikelets about
1 em. long, the lemma narrow, acuminate-pointed, the palea a little shorter? acute; pistillate
spikelets glabrous, the glume and sterile lemma 5-nerved, rather thin, somewhat reticulate
with cross veins, gradually acuminate, pointed, the glume (including the point) about 2 cm.
long, the sterile lemma a little shorter; fruit narrow, about 8 mm. long, narrowed to an obtuse
apex, glabrous, minutely pitted, the pits oblong; palea nearly as long as the lemma, almost
inclosed by the margins of the lemma.

TYPE LocALITy: El Mufieco, Costa Rica.
DISTRIBUTION: Known only from the type collection.

2. Olyra yucatana Chase, Proc. Biol. Soc. Wash. 21: 178. 1908.

Stems tall, slender; leaf-sheaths mostly longer than the internodes, crisp-puberulent;
blades oblong-lanceolate, 13-16 cm. long, one third as wide, abruptly acuminate, trapezoid-
truncate at base; panicles contracted, often a second one from the upper sheath, 8—15 em. long,
2 cm. wide, axis and rachis scabrous; staminate spikelets on the lower branches and lower
part of upper pistillate branches, 8 mm. long including the setaceous tip of the lemma, palea
about 2 mm. shorter; pistillate spikelets 15-17 mm. long, the glume and sterile lemma
scabrous, 7-nerved, 8 mm. long, and acuminate into flexuous setaceous tips as long again in
the glume, half as long in the sterile lemma; fruit elliptic, obscurely pointed, 7 mm. long,
4 mm. wide, white and shining or old ivory toward maturity, the lemma silky-pubescent at
base and on the margins.

TYPE LocALITY: Pocoboch, Yucatan.
DISTRIBUTION: Yucatan.
ILLUSTRATION: Field Mus. Publ. Bot. 3: 46.

3. Olyra caudata Trin. Linnaea 10: 292. 1836.

Olyra Pittieri Hack. Oesterr. Bot. Zeits. 51: 461. 1901.

Stems simple, 60 cm. or more tall, glabrous; leaf-sheaths longer than the internodes,
glabrous; ligule firm, rounded, puberilent, 3-5 mm. long; blades oblong-lanceolate, 20-26 cm.
long, 6-7 cm. wide, abruptly narrowed at the somewhat unequal base into a hispidulous
petiole about 3 mm. long, acuminate, scabrous on the margin, especiaily at apex, glabrous,
somewhat glaucous and weakly reticulate beneath, scaberulous beneath at apex; panicle
corymbiform, simple, spreading, the axis short, the branches (racemes) 6—8, simple, fastigiate,
as much as 10 cm. long, the rachis compressed-triangular, the angles scabrous; staminate
spikelets in twos or threes along the raceme, shortly pedicelled, the pistillate single at the apex
of each raceme; staminate spikelets 7 mm. long, linear-lanceolate, acute, awnless, glabrous,
the glume and sterile lemma 3-nerved; glume and sterile lemma of pistillate spikelets ovate,
scaberulous, 7- to 9-nerved, about | cm. long, extending into a slender scabrous point 3-4 cm.
long (total length 4-5 cm.); fertile lemma oblong-ovate, smooth, 9-10 mm. long, 5 mm. wide,
slightly umbonate, gray or plumbeous.

TYPE LOCALITY: Peru.
DisTRrBuTioN: Costa Rica to Brazil and Pern.

4. Olyra latifolia L. Syst. Nat. ed. 10.1261. 1759.

Olyra paniculata Sw. Prodr. 21. 1788.
Olyra arundinacea H.B.K. Nov. Gen. & Sp. 1:197. 1816.
Olyra latifolia arundinacea Griseb. Fl. Brit. W. Ind. 535. 1864.

Glabrous perennial, bamboo-like in aspect, commonly 5 meters tall, the strong hollow
stems sometimes 1 cm. thick, erect and unsupported, the summit only arching (or weaker
stems leaning among brush), the lower half to two thirds simple and naked, the short sheaths

Part 4, 1931] POACEAE 351

bladeless or nearly so, the elongate internodes blotched with dull purple, branching from the
upper nodes, the branches commonly fascicled, divaricate, often 1 meter long, sometimes
again branching; leaf-sheaths glabrous, puberulent, scaberulous or hispidulous; ligule mem-
branaceous or chartaceous, 1-5 mm. long, puberulent or glabrous; blades oblong-lanceolate,
glabrous or puberulent or scaberulous, rounded or subcordate at the unequal base, contracted
into a glabrous or hispidulous petiole 1-2 mm. long, acuminate, as much as 25 cm. long and
10 cm. wide on the primary culms, often much smaller on the branches, the lowermost on both
primary culm and branches rudimentary; panicles 10-15 cm. long, about two thirds as wide,
those of the secondary branches reduced, the branches stiffly ascending or spreading, each
bearing a single large long-acuminate pistillate spikelet at the thickened summit and several
small slender-pedicelled staminate spikelets along the rachis; staminate spikelets 3-5 mm.
long, narrow, the lemma extending into an awn about 5 mm. long, the palea similar, acuminate;
second glume and sterile lemma of pistillate spikelets membranaceous, ovate-lanceolate,
glabrous or scabrous, 7- to 9-nerved, acuminate or extending into a scabrous point as much
as 2 cm. long; fruit oval, rounded at both ends, flattened, 4-5 mm. long, 3 mm. wide, smooth
and shining, pearly white, gray, or plumbeous.

TYPE LOCALITY: Jamaica.

DISTRIBUTION: Mexico and the West Indies to Brazil; reported from Florida.

- IniLustRaTIons: Trin. Ic. pl. 346; Bull. U.S. Dep. Agr. 772: f. 153; Proc. Biol. Soc. Wash. 21:
L777. f- 1.

5. Olyra cordifolia H.B.K. Nov. Gen. & Sp. 1: 198. 1816.

Resembling O. latifolia; leaf-blades on the average larger, glabrous, oblong, abruptly
rounded to the cordate symmetric base, rather abruptly narrowed toward apex to a slender
twisted point, 15-25 cm. long, 7-10 cm. wide, the pubescent petiole mostly less than 5 mm. long.

Type Loca.ity: Brazil.

DISTRIBUTION: Southern Mexico; also from Venezuela to Paraguay.
ILLUSTRATION: Trin. Ic. pl. 342.

6. Olyra lateralis (Presl) Chase, Proc. Biol. Soc. Wash. 21:
179. 1908.

Panicum laterale Presl, Rel. Haenk. 1: 305. 1830.

Plants much-branched, straggling or climbing; stems slender, rather wiry, glabrous, the
nodes swollen, more or less pubescent; leaf-sheaths pubescent, striate, villous on the margin,
mostly 1-2 cm. long, the truncate summit bearing a few long cilia; ligule a membrane less
than 0.5 mm. long, bearing short cilia; blades oblong-lanceolate, 1.5-4.5 em. long, 7-12 mm.
wide, slightly ciliate and more or less puberulous at the truncate or subcordate base, the width
about the same in the lower third or half, gradually narrowed above to a rounded tip, this acute
or slightly apiculate, the surface glabrous or slightly scabrous above, glabrous and sometimes
glaucous beneath, several-nerved, striate between the nerves, the petiole pubescent, about 1
mm. long; panicles on slender peduncles, ovoid, 2-3 cm. long, rarely longer, few-flowered, the
branches terete, glabrous, or the lower puberulent, the pulvini slightly puberulent; staminate
spikelets appressed on the lower branches; pistillate spikelets elliptic or ovoid, flattish on one
side, convex on the other, 2.5 mm. long, 1.4 mm. wide, apiculate, pubescent, brown at maturity;
second glume and sterile lemma about equal, the latter inclosed within the margins of the
former, the sterile palea wanting; fruit smooth, brownish, inclosed within the margins of the
sterile lemma, about 1.5 mm. long, | mm. wide.

TYPE LOCALITY: Peru. ‘
DISTRIBUTION: Costa Rica to Bolivia.

78. LITHACHNE Beauv. Agrost. 135. 1812.

Cespitose herbaceous perennials with simple stems, the blades contracted at base and
convolute in the bud as in Olyra. Spikelets unisexual, unlike in appearance; inflorescence
consisting of few to several small panicles or racemes, solitary or borne in fascicles of two to
five, short-exserted from the sheaths, each bearing one pistillate spikelet on a clavate pedicel

352 NORTH AMERICAN FLORA [VOLUME 17

at the summit, and one to several staminate spikelets on slender pedicels below; a narrow,
short-exserted, terminal, wholly staminate panicle often present, rarely a fascicle of 2 or 3 such
panicles; pistillate spikelets V-shaped owing to the greatly swollen fertile lemma; first glume
wanting; second glume and sterile lemma membranaceous, nerved, unequal, long-acuminate;
fruit laterally subcompressed (forming an exception to the tribe character of dorsally com-
pressed fruit in Paniceae); lemma and palea thick bony-indurate, the lemma greatly swollen
or gibbous on the back, so as to appear in side view half obcordate-truncate, the margins
inrolled over a narrow palea; grain laterally subcompressed, inclosed in the lemma and palea.
Staminate spikelets narrowly lanceolate, reduced to the thin-membranaceous lemma and
palea and 3 stamens.
Type species, Olyra pauciflora “1,.”’ [Sw.].

Leaf-blades 1.5-3 cm. wide. 1. L. pauci flora.
Leaf-blades less than 5 mm. wide. 2: L. Panets-

1. Lithachne pauciflora (Sw.) Beauv.; Poir. Dict. Sci. Nat. 27:
60. 1823.
Olyra pauciflora Sw. Prodr. 21. 1788.

Olyra axillaris Lam. Encyc. 4: 547. 1797.
Lithachne axillaris Beauv. Agrost. 166. 1812.

Stems tufted, slender, hard, glabrous, geniculate and naked below, ascending and leafy
above, 30-50 cm. tall; leaf-sheaths mostly shorter than the internodes, striate, glabrous or
puberulous between the nerves, ciliate; ligule a short membrane less than 0.5 mm. long; blades
flat, asymmetrically rhombic-lanceolate, 5—8 cm. long, 1-2.5 cm. wide, acuminate, spreading,
glabrous, sometimes puberulous around the base or sparsely hispidulous, scabrous on the
margin and toward apex, contracted into a petiole about 1 mm. long, this puberulous and also
hispid; panicles narrow and few-flowered, from the upper sheaths, more or less included,
the branches ascending or appressed; staminate spikelets narrow, 3-4 mm. long, the lemma
3-nerved, scabrous on the keel, acuminate into a short awn, the palea similar, 2-nerved, acu-
minate, a little shorter than the lemma; pistillate spikelets usually only 1-3 in each panicle,
the second glume and sterile lemma similar, oblong, abruptly narrowed above the fruit into
a slender point, in all 8-10 mm. long, 7- to 9-nerved, glabrous; fruit pearly-white, triangular-
truncate, 4-5 mm. long, 3 mm. wide at summit.

TYPE LOCALITY: Jamaica.
DISTRIBUTION: West Indies and southern Mexico to northern Argentina.
ILLUSTRATIONS: Proc. Biol. Soc. Wash. 21: 181, f. 2; Beauv. Agrost. pl. 24, f. 11.

2. Lithachne Pineti (Wright) Chase, Proc. Biol. Soc. Wash. 21:
182. 1908.
Olyra Pineli Wright; Griseb. Mem. Am. Acad. IT. 8: 532. 1862.

Stems tufted, spreading, capillary, glabrous, about 20 cm. long, naked below; leaf-sheaths
about 1 cm. long, sulcate, glabrous; ligule a short membrane less than 0.5 mm. long; blades
flat, spreading or reflexed, rather remote below, somewhat crowded at summit, oblong-elliptic,
10-15 mm. long, 2-3 mm. wide, rounded at base, rather abruptly acute at apex, many-nerved,
glabrous or slightly scabrous, the petiole less than 1 mm. long, hispidulous; panicles 1 to few-
flowered from the upper sheaths; staminate spikelets lanceolate-acuminate; pistillate spikelets
about as in L. pauciflora, the second glume and sterile lemma about 5 mm. long; fruit about
3 mm. long, apiculate.

TYPE LocaLity: Eastern Cuba.

DISTRIBUTION: Cuba and Haiti.
79. RADDIA Bertol. Opusce. Sci. Bologna 3: 410. 1819.

Strephium Schrad.; Nees, Agrost. Bras. 298. 1829.
Low cespitose herbaceous perennials with simple stems, the blades narrowed at the base,
the creases (folds in the bud) indistinct, usually conspicuously distichous and turned with

Part 4, 1931] POACEAE 353

the surfaces on a single plane. Spikelets unisexual, unlike in appearance; the staminate and
pistillate in distinct small panicles, the staminate terminal or from the upper nodes, the
pistillate axillary, short-exserted, few-flowered, usually from the lower nodes (a few staminate
spikelets sometimes borne below the pistillate spikelets); pistillate spikelets lanceolate; first
glume wanting, second glume and sterile lemma membranaceous, strongly nerved, subequal,
acuminate; fruit dorsally subcompressed, lanceolate, acute; lemma and palea bony-indurate
but less so than in Olyra and Lithachne, the margins flat, nearly meeting over the palea.
Staminate spikelets linear-lanceolate.

Type species, R. brasiliensis Bertol.
Sheaths glabrous or nearly so.

Blades 4-7 cm. long.

Blades 1.5-3 cm. long.
Sheaths densely hirsute.

. Stricti flora.
. concinna,
. costaricensis.

eer
cicelas!

1. Raddia strictiflora (Fourn.) Chase, Proc. Biol. Soc. Wash. 21:
So. 908;
Strephium strictiflorum Fourn. Bull. Soc. Bot. Belg. 15: 465. 1876.
Olyra strictiflora Hemsl. Biol. Centr. Am. Bot. 3: 510. 1885.

Stems cespitose, ascending from a geniculate base, striate, puberulent between the nerves,
30-50 cm. tall, naked below, the leaves crowded toward the summit; leaf-sheaths striate,
glabrous, or puberulent between the nerves, ciliate, produced upward on each side 1-3 mm.;
ligule firm, rounded, extending between the projections of the sheath, puberulent, 1-3 mm.
long; blades oblong-elliptic, 3-6 cm. long, 1.5—2 cm. wide, rounded below into a pubescent
petiole about 1 mm. long, abruptly contracted at apex into an acuminate subulate point,
glabrous, or slightly scaberulous above; panicles narrow, the branches appressed, more or less
included in the upper sheaths, 2-4 cm. long; staminate spikelets narrow, about 5 mm. long,
acuminate, the lemma membranaceous, 3-nerved, the palea similar, 2-nerved, a little shorter
than the lemma; pistillate spikelets narrow, 10-12 mm. long, 2 mm. wide, the second glume and
sterile lemma similar, rather firm, oblong, acuminate, 7—9-nerved, the 2 or 3 pairs of nerves
near the margin, leaving a wide internerve on each side the midnerve, glabrous or minutely
seaberulous; fruit about 7 mm. long and 1.5 mm. wide, brownish.

TyPr LocaLity: Arroyo Sellero, Mexico.
DISTRIBUTION: Southern Mexico to Honduras.

2. Raddia concinna (Hook. f.) Chase, Proc. Biol. Soc. Wash. 21:
185. 1908.
Olyra concinna Hook. f. Bot. Mag. pl. 7469. 1896.

Stems cespitose, slender, erect, 15-30 cm. tall, the conspicuously d’stic! ous leafy shoots
resembling the pinnately compound leaves of a legum‘nous plant, tke leaf-steatts overlapping,
slightly compressed; blades oblong, 1.5-3 em. long, 5-10 mm. wice, somewlat abruptly
pointed, glaucous beneath; staminate spikelets about 1 cm. long, on slender pedicels;
pistillate spikelets 7-10 mm. long, on thickened pedicels; fruit a little storter t!an the glume
and sterile lemma, narrow, nearly terete, smooth and glabrous.

Type LocaALity: San José, Costa Rica.
DistrRigution: Nicaragua and Costa Rica.
ILLUSTRATION: Bot. Mag. pl. 7469.

3. Raddia costaricensis Hitchc. Proc. Biol. Soc. Wash. 40:
Sr. L927.

Erect cespitose perennial; stems stiff, sometimes bent at the nodes, glabrous, 20-30 cm.
tall; leaf-sheaths overlapping, densely hirsute; blades crowded, rather firm and stiffly spreading,
oblong-lanceolate, rounded at base, acute, 3-4 cm. long, 4-6 mm. wide, villous beneath, glabrous
or sparsely hirsute on the upper surface, revolute in drying; staminate panicles narrow, pale,
the spikelets 3-4 mm. long; pistillate panicles consisting of a few (apparently 1 or 2) pistillate

354 NORTH AMERICAN FLORA [VoLUME 17

spikelets and several staminate ones below, the pistillate spikelets glabrous, 7 mm. long, with
an apiculation 1.5 mm. long; staminate spikelet glabrous, pale, 3 mm. long.

TYPE LocaLity: Rio Hondo, Costa Rica. ,
DISTRIBUTION: Known only from the type collection.

80. MNIOCHLOA Chase, Proc Biol. Soc. Wash. 21: 185. 1908.

Low tufted perennials, the flowering stems with 1-3 nodes, the short sheaths destitute
of blades, distinct from the sterile stems, which bear several to many more or less distichous,
flat, ovate-lanceolate blades less than 2 cm. long, narrowed into a short petiole. Inflorescence
monoecious, consisting of two slender spike-like racemes, one pistillate, the other staminate,
at the summit of a slender naked culm; pistillate spikelets dorsally compressed, 1-flowered,
lanceolate-oblong, solitary on very short clavate pedicels along one side of a slender triangular
rachis; first glume wanting, second glume and sterile lemma subequal, not setaceous; fertile
lemma white-cartilaginous, subindurated, the margins flat, infolding a palea of like texture
and equal length; grain dorsally compressed; staminate spikelets smaller than the pistillate,
glumes and sterile lemma wanting, lemma and palea membranaceous, equal, the lemma
1-nerved, palea 2-nerved; stamens 3.

Type species, Digitaria pulchella Griseb.

Flowering stems much exceeding the sterile ones; fruit glabrous.

1. M. pulchella.
Flowering stems about equal in height; fruit pubescent. 2. M.

strephioides.

1. Mniochloa pulchella (Griseb.) Chase, Proc. Biol. Soc. Wash. 21:
186. 1908.

Digitaria pulchella Griseb. Cat. Pl. Cub. 231. 1866.
Strephium? pulchellum Wright; Sauy. Anal. Acad. Ci. Habana 8: 202. 1871.

Flowering stems filiform, 15-25 em. tall, the nodes 2 or 3, at least the lower geniculate,
the upper internode and peduncle elongate; sterile stems spreading or prostrate, the distichous
leaves approximate; leaf-sheaths of fertile stem slightly inflated, 1-3 cm. long, those of the
sterile shoots ciliate on the margin and at the summit, at least the upper overlapping; blades
firm, oblong-ovate, 8-18 mm. long, 3-5 mm. wide, subacute, sparsely hairy along the mid-
nerve, pale green above, dark purplish beneath, undulate on the margins; racemes erect or
ascending, 2-3.5 em. long, the staminate slightly shorter than the pistillate; spikelets glabrous,
2.5 mm. long; staminate spikelets 1.5 mm. long, glabrous, the glume and sterile lemma of the
pistillate spikelets about one fourth shorter than the glabrous fruit.

Type LocaLity: El Yunque de Baracoa, Cuba.

DISTRIBUTION: Known only from the type collection.
ILLUSTRATION: Proc. Biol. Soc. Wash. 21: pl. 4.

2. Mniochloa strephioides (Griseb.) Chase, Proc. Biol. Soc.
Wash. 21: 186. 1908.
Olyra strephioides Griseb. Cat. Pl. Cub. 229. 1866.

Flowering stems slender, 4-7 cm. tall, equaling or shorter than the sterile stems; sterile
stems less delicate than in the preceding, puberulent in lines, naked below, the nodes pubescent;
leaf-sheaths striate, puberulent, ciliate on margin and at summit, the upper overlapping;
blades triangular-ovate, rather firm, 10-15 mm. long, 4-8 mm. wide, truncate and somewhat
unequal at base, striate with many nerves, scaberulous, or puberulent beneath; racemes
erect, 1-3 cm. long, about equal; staminate spikelets scarcely half as long as the pistillate,
glabrous; pistillate spikelets 3.5 mm. long, the glume and sterile lemma glabrous, exceeding
the fruit; fruit clothed with white silky hairs.

TYPE LOCALITY: Western Cuba.
DISTRIBUTION: Western Cuba.

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