The Manual of the Botany of the Northern United States Part 197

Spikelets spiked or somewhat racemed, in 2--4 rows on one side of a flattened or filiform continuous rhachis, jointed upon very short pedicels, plano-convex, awnless, 1-flowered. Glumes 3 (rarely only 2), the terminal one flowering. Flower coriaceous, mostly orbicular or ovate, flat on the inner side, convex on the outer. Stamens 3. Spikes one or more, at or toward the summit of an elongated peduncle.

(?asp????, a Greek name for Millet.)

[*] _Spikes with a (1") broad and thin membranaceous or foliaceous and keeled rhachis, the incurved margins partly enclosing the small two-rowed spikelets. (Smooth, aquatic, or nearly so, dec.u.mbent or floating.)_

1. P. fluitans, Kunth. Annual; _leaves lanceolate, flat_ (3--8"), broad; _spikes numerous in a raceme_, the rhachis somewhat projecting beyond the minute and slightly p.u.b.escent spikelets into a tapering point, scabrous on the back.--River-swamps, Va. to S. Ill., Mo., and southward. Sept., Oct.

2. P. Walterianum, Schultes. Perennial; _leaves linear, short; spikes_ 3--7, the lowest partly included in the sheath of the uppermost leaf, the rhachis blunt; spikelets glabrous.--Low or wet grounds, N. J. (Cape May, _Nuttall_), Del., and southward.

[*][*] _Spikes with a narrow wingless rhachis; perennials, or mostly so._

[+] _Spikelets very obtuse, orbicular; spikes one terminal and often 1--5 lateral._

3. P. setaceum, Michx. Culm ascending or dec.u.mbent (1--2 long), slender; leaves (2" wide, flat) and sheaths clothed with soft spreading hairs; _spikes very slender_ (2--4' long), smooth, _mostly solitary on a long peduncle, and usually one from the sheaths of each of the upper leaves on short peduncles or included_; _spikelets_ (" wide) _narrowly 2-rowed_.--Sandy fields; common from E. Ma.s.s. to Ill., and southward.

Aug.

4. P. lae've, Michx. (Pl. 13, fig. 1--3.) Bright green, sparingly villous, rather stout; stems somewhat dec.u.mbent; leaves and spikes widely spreading; spikes (2--4) approximate, 2--4' long, smooth or nearly so; spikelets about 1" wide, 2-rowed.--Moist soil, S. New Eng. to Ky., and southward.

5. P. Floridanum, Michx. Stout, erect, 3--6 high, glaucous; sheaths and leaves more or less villous, the latter and the spikes erect or ascending; spikes (2--5) broader, 2--5' long, the smooth spikelets nearly 2" broad, in 2 rows.--Moist soil; Del. to Fla., Ark., and Tex.

[+][+] _Spikelets acute; spikes several, racemose._

6. P. dilatatum, Poir. Stout, erect, 2--5 high, villous at the top of the sheath; spikes few on a naked peduncle, erect, 2--3' long; spikelets 1" long or more, the lower glume soft-villous on the margin.--Va. to Tex.

[+][+][+] _Spikelets acute; spikes always a pair at the summit of the naked peduncle._

7. P. distichum, L. (JOINT-GRa.s.s.) Nearly glabrous, rather glaucous; culms ascending (about 1 high) from a long creeping base; leaves linear-lanceolate (2--3' long); peduncle usually short; _spikes short_ and closely-flowered (9"--2' long), often slightly separated; rhachis flat on the back; _spikelets ovate, slightly pointed_ (barely 1"

long), _approximate on one side of the rhachis_.--Wet fields, Va. and southward. July--Sept.

8. P. Elliottii, Watson. Culms ascending (1--2 high) from a creeping base; leaves lanceolate (3--6' long, 4--6" wide); _spikes slender_, rather spa.r.s.ely flowered (1--4' long), _both sessile_ upon the long slender peduncle; _spikelets ovate-lanceolate_ (2" long), _on nearly opposite sides of the rhachis_. (Milium paspaldes, _Ell._ P. Digitaria, _Chapm._; not _Poir._)--Va. and southward.

4. ERIoCHLOA, HBK. (Pl. 16.)

Spikelets ovate, subsessile or shortly pedicelled upon one side of the rhachis of a spike, with a callus at base and jointed on the pedicel, 1-flowered. Glumes 3, the 2 empty ones slightly unequal, membranaceous, acute, the flowering one shorter, indurated, obtuse, enclosing the free grain.--Coa.r.s.e tufted gra.s.ses, with flat leaves, the spikes more or less scattered along a common peduncle, and the pedicels and rhachis of the spike usually p.u.b.escent or hairy (hence the name, from ?????, _wool_, and ???a, _gra.s.s_).

1. E. polystachya, HBK. Culms erect or dec.u.mbent, 2 high; spikes 6--12, erect or ascending, 1--2' long, forming a compound spike 3--6' long; spikelets glabrous, very shortly pedicelled, oblong-lanceolate, nearly 2" long.--S. Kan. to Tex. and Mex.

5. PaNIc.u.m, L. PANIC-GRa.s.s. (Pl. 13.)

Spikelets jointed upon the pedicels, ovate, panicled, racemed, or sometimes spiked, not involucrate, with one perfect and sometimes a second lower rudimentary or staminate flower. Glumes 4, but the lower one usually short or minute (rarely even wanting), and the third empty or sterile, membranaceo-herbaceous. Upper flower perfect, closed, coriaceous or cartilaginous, usually flattish parallel with the glumes, awnless (except in -- 3), enclosing the free and grooveless grain.

Stamens 3. Stigmas plumose, usually purple. (An ancient Latin name of the Italian Millet, P. Italic.u.m (now Setaria Italica), of uncertain origin and meaning.)

-- 1. DIGITaRIA. _Spikelets crowded 2--3 together in simple and mostly 1-sided cl.u.s.tered spikes or spike-like racemes, wholly awnless and pointless, 1-flowered; lower glume minute or obsolete or wanting; annual, often purplish._

[*] _Spikes erect; the rhachis filiform and nearly terete._

1. P. filiforme, L. Culms very slender (1--2 high), upright; lower sheaths hairy; spikes 2--8, alternate, approximate, filiform; spikelets oblong, acute (" long); lower glume almost wanting.--Dry sandy soil, Ma.s.s. to N. J. along the coast, to Iowa, Neb., and southward. Aug.

[*][*] _Spikes spreading; the rhachis flat and thin._

P. GLaBRUM, Gaudin. Culms spreading, prostrate, or sometimes erect (5--12' long), glabrous; _spikes 2--6, widely diverging_, nearly digitate; spikelets ovoid (about 1" long); _upper empty glume equalling the flower, the lower almost wanting_.--Cultivated grounds and waste places; common, especially southward; sometimes appearing indigenous.

Aug., Sept. (Nat. from Eu.)

P. SANGUINaLE, L. (COMMON CRAB- or FINGER-GRa.s.s.) (Pl. 13, fig. 1--3.) Culms erect or spreading (1--2 high); leaves and sheaths glabrous or hairy; _spikes 4--15, spreading_, digitate; spikelets oblong (1"

long); _second glume half the length of the flower, the lower one small_.--Cultivated and waste grounds. Aug.--Oct. (Nat. from Eu.)

-- 2. PANIc.u.m proper. _Spikelets scattered, in panicles, awnless._

[*] _Panicle elongated and racemose, wand-like or pyramidal; the numerous and usually pointed spikelets short-pedicelled, excepting n. 3 and 4._

[+] _Sterile flower none; lower glume short; spikelets --1" long; annuals except_ n. 4; _leaves flat; sheaths flattened._

[++] _Glabrous and smooth throughout; spikelets appressed, short-pedicelled._

2. P. proliferum, Lam. Culms usually thickish and rather succulent, branched, geniculate and ascending from a proc.u.mbent base; sheaths flattened; ligule ciliate; panicles terminal and lateral, compound, pyramidal, the slender primary branches at length spreading; spikelets pale green, rarely purplish; lower glume broad, {1/3} to the length of the upper, which is little longer than the flowering one.--Marshy river-banks and sh.o.r.es, especially if brackish, but also in the interior, from Ma.s.s. to Iowa, and southward. Aug.

[++][++] _Hispid or hairy on the sheaths, at least the lower; spikelets mostly scattered on slender pedicels in an ample, loose, at length very effuse panicle; culms mostly branched from the base, erect or ascending (10--20' high)._

3. P. capillare, L. (OLD-WITCH GRa.s.s.) (Pl. 13, fig. 4, 5.) All the sheaths and usually the leaves _copiously hairy or hispid_; panicle mostly very compound, the branches divaricate when old; spikelets from ovoid to narrowly oblong, pointed; _lower glume half the length of the upper empty one_, which is longer than the _elliptical obtuse perfect flower_.--Sandy soil and cultivated fields everywhere.

Aug.--Oct.--Varies extremely in size and appearance, the culms erect and simple, or dec.u.mbent, geniculate and branched; in depauperate forms the spikelets only ", in the larger forms 1" in length.

4. P. autumnale, Bosc. Root perennial (?), lower sheaths and margins of the small narrow leaves more or less hairy, _otherwise glabrous_, except some _bristly hairs in the main axils of the very effuse capillary panicle_, its much elongated divisions sparingly branched, or even simple and terminated with solitary _spindle_-shaped spikelets; _lower glume minute; perfect flower lanceolate-oblong and pointed_, nearly equalling the lance-oblong obtusish empty glumes.--Sand-hills, Ill. to Minn., Mo., and southward.

[+][+] _Sterile flower rudimentary (staminate in n. 7), its glume fully twice the length of the lower glume; spikelets small (1 or 1" long); root perennial._

5. P. anceps, Michx. _Culms flat, upright_ (2--4 high); leaves rather broadly linear (1--2 long, 4--5" wide), smooth; panicle contracted-pyramidal; _spikelets ovate-lanceolate, pointed_, a little curved; _second glume 5--7-nerved_; neutral flower one third longer than the perfect one.--Wet sandy soil, N. J. and Penn. to S. Ill., and southward. Aug.--Spikelets larger and branches of the panicle longer and narrower than in the next.

6. P. agrostodes, Muhl. _Culms flattened, upright_ (2--4 high); leaves long, and with the sheaths smooth; panicles terminal and often lateral, pyramidal (4--8' long); _spikelets_ racemose, crowded and one-sided on the spreading branches, _ovate-oblong, acute_ (purplish); _second glume 5-nerved_, longer than the neutral flower; perfect flower shorter, bearded at the apex.--Wet meadows and sh.o.r.es, E. Ma.s.s. to Minn., Neb., and common southward. Aug.

7. P. Curtisii, Chapm. Culms stout, 3--4 high, often rooting below; mostly glabrous; panicle slender, simple, spike-like (6--8' long), the spikes appressed; spikelets lanceolate, acute; lower glume half the length of the 5-nerved second one.--Ponds, Del. to Fl. and Tex.

[+][+][+] _Sterile flower staminate; lower glume more than half the length of the next; spikelets large (2--2" long), ovate, pointed, as are the glumes, etc.; perennials, glabrous, with tall or stout and rigid upright culms._

8. P. virgatum, L. (Pl. 13, fig. 8, 9.) Tall (3--5 high); _leaves very long, flat_; ligule silky-bearded; _branches of the compound loose and large panicle_ (9'--2 long) _at length spreading or drooping_; spikelets scattered, usually purplish.--Moist sandy soil; common. Aug.

9. P. amarum, Ell. Culms (1 high or more) sheathed to the top; _leaves involute, glaucous, coriaceous, the uppermost exceeding the contracted panicle_, the simple racemose branches of which are appressed; spikelets pale.--Sandy sh.o.r.es, Conn., Va., and southward. Aug., Sept.--The northern form (var. MNUS, Vasey & Scribn.) somewhat smaller than the southern.

[*][*] _Panicle short or small, loosely spreading or diffuse; perennials._

[+] _Sterile flower none; spikelets warty roughened._

10. P. verrucsum, Muhl. Smooth; culms branching and spreading, very slender (1--2 long), naked above; leaves linear-lanceolate (2--3"

wide), shining; branches of the diffuse panicle capillary, few-flowered; spikelets dark green, oval, acute, " long; lower glume as long as the faintly nerved second.--Sandy swamps, N. Eng. to Va., near the coast, and southward.

[+][+] _Lower (sterile) flower neutral, or in n. 12 and sometimes in n. 11 staminate, the palet scarious and sometimes small and inconspicuous._

[++] _Culm-leaves broadly lanceolate or wider, with 9--15 princ.i.p.al nerves (obscure or none in n. 17)._