17. Anthoxanthum. Middle glumes empty, awned on the back. Stamens 2.

18. Hierochloe. Middle glumes triandrous. Fertile flower diandrous.

Tribe VI. AGROSTIDEÆ. Glumes 3; flower solitary, perfect (rarely a rudimentary or perfect second flower in n. 23 and 32–34), palet 2-nerved.

[*] Flowering glume with a terminal awn (none in n. 22), closely embracing the grain in fruit; spikelets in panicles or loose spikes, the rhachis not produced beyond the flower (except in n. 24 and a single species of n. 23).—Stipeæ.

[+] Fruiting glume firm and indurated, with a callus at base (none in n. 22).

19. Aristida. Awn 3-fid, the branches divaricate. Callus acute.

20. Stipa. Awn simple, twisted. Callus mostly acute.

21. Oryzopsis. Awn simple, straight, deciduous. Flower oblong; callus short, obtuse.

22. Milium. Awn none. Flower small, ovoid, without callus.

[+][+] Fruiting glume thin and membranous; outer glume smaller or minute.

23. Muhlenbergia. Flower mostly hairy at base, the glume mucronate or awned.

24. Brachyelytrum. Rhachis produced into a bristle above. Outer glumes very small, the flowering one long-awned. Stamens 2.

[*][*] Flowering glume awnless or short-awned, loosely embracing the grain, thin, the lower glumes complicate carinate; spikelets in dense spike-like panicles, the rhachis not produced.—Phleoideæ.

25. Heleochloa. Awns none. Spikes short and scarcely exserted.

26. Phleum. Glumes somewhat truncate, mucronate or short awned. Spike cylindric.

27. Alopecurus. Lower glumes united at base, the flowering awned on the back. Palet none. Spike cylindric.

[*][*][*] Glumes membranous, the lower rarely strongly complicate, the flowering with a dorsal awn or awnless; spikelets variously panicled.—Agrosteæ.

[+] Flowering glume 1- (rarely 3-) nerved, awnless; grain loosely enclosed or naked.

28. Sporobolus. Culms wiry or rigid. Leaves involute.

[+][+] Flowering glume 3–5 nerved, mostly awned; grain enclosed.

[++] Rhachis not reduced above the single flower.

29. Agrostis. Spikelets in an open panicle.

30. Polypogon. Empty glumes long-awned. Panicle spike-like.

31. Cinna. Spikelets flattened, in a loose panicle. Palet 1-nerved. Stamen 1

[++][++] Rhachis bearing a rudimentary second flower or short bristle (except in species of n. 33).

[*][*][*] Glume 3-nerved, the nerves (at least the mid-nerve) excurrent; spikelets few, in the axils of floral leaves.

75. Elymus. Spikelets 1–several-flowered, all perfect and similar.

1. SPARTÌNA, Schreber. Cord or Marsh Grass. (Pl. 9.)

Spikelets 1-flowered, very much flattened laterally, jointed and sessile in 2 ranks on the outer side of a triangular rhachis. Glumes 3, unequal, lanceolate, strongly compressed-keeled, acute or bristle-pointed, mostly rough-bristly on the keel; palet thin, equalling or longer than the flowering glume. Stamens 3. Styles long, more or less united.—Perennials, with simple and rigid often reed-like culms, from extensively creeping scaly rootstocks, racemed spikes, very smooth sheaths, and long tough leaves (whence the name, from σπαρτίνη, a cord, such as was made from the bark of the Spartium or Broom).

[*] Spikelets compactly imbricated, very rough-hispid on the keels; spikes (2–4´ long) more or less peduncled; culm and elongated leaves rigid.

1. S. cynosuroìdes, Willd. (Fresh-water Cord-Grass.) Culm rather slender (2–6° high); leaves narrow (2–4° long, ½´ wide below or less), tapering to a very slender point, keeled, flat, but quickly involute in drying, smooth except the margins; spikes 5–20, scattered, spreading; rhachis rough on the margins; glumes awn-pointed, especially the middle one (its awn about ¼´ long), strongly serrulate-hispid on the keel, the lower equalling the upper, whose strong midrib abruptly terminates below the membranous apex.—Banks of rivers and lakes, or in rich soil, especially northward. Aug.

2. S. polystàchya, Willd. (Salt Reed-Grass.) Culm tall and stout (4–9° high, often 1´ in diameter near the base); leaves broad (½–1´), roughish underneath, as well as the margins; spikes 20–50, forming a dense oblong raceme (purplish); glumes barely mucronate, the lower half the length of the flowering one, of which the rough-hispid midrib reaches to the apex.—Salt or brackish marshes, within tide-water, especially southward.

3. S. júncea, Willd. (Rush Salt-Grass.) Culms low (1–2° high) and slender; leaves narrow and rush-like, strongly involute, very smooth; spikes 1–5, on very short peduncles, the rhachis smooth; glumes acute, the lower scarcely half the length of the middle one, not half the length of the upper.—Salt marshes and sea-beaches. Aug. (Eu.)

[*][*] Spikelets loosely imbricated, or somewhat remote and alternate, the keels only slightly hairy or roughish under a lens; spikes sessile and erect, soft; leaves, rhachis, etc., very smooth; culm rather succulent.

4. S. strícta, Roth. (Salt Marsh-Grass.) (Pl. 9, fig. 1–3.) Culm 1–4° high, leafy to the top; leaves soon convolute, narrow; spikes few (2–4), the rhachis slightly projecting beyond the crowded or imbricated spikelets; glumes acute, very unequal, the larger 1-nerved, a little longer than the flower.—Salt marshes, Penn., etc.—Odor strong and rancid. (Eu.)

Var. glàbra, Gray. Culm and leaves longer; spikes 5–12 (2–3´ long); Spikelets imbricate-crowded.—Common on the coast.

Var. alterniflòra, Gray. Spikes more slender (3–5´ long), and the spikelets remotish, barely overlapping, the rhachis continued into a more conspicuous bract-like appendage; larger glume indistinctly 5-nerved; otherwise as in the preceding form, into which it passes.—Common with the last; also Onondaga Lake, J. A. Paine.

2. BECKMÁNNIA, Host. (Pl. 16.)

Spikelets jointed upon the pedicels, 1–2-flowered (only one fertile), obovate and laterally compressed, imbricated in 2 rows upon one side of the angled rhachis of a spike. Glumes 3 or 4, the 2 lower strongly concave and carinate, obtuse or acutish, the 1 or 2 flowering glumes narrower, lanceolate, acute or acuminate and a little exserted, becoming rather rigid and with the thin palet enclosing the oblong grain.—A stout erect subaquatic perennial, with the short spikes erect and simply spicate or in a strict narrow panicle. (Named for John Beckmann, professor of botany at Goettingen.)

1. B. erucæfórmis, Host, var. uniflòra, Scribn. Glumes 3 and spikelets 1-flowered; spikes (6´´ long or less) panicled.—N. W. Iowa, W. Minn., and westward. The Old World form, which also is found in the far northwest, has 2-flowered spikelets.

3. PÁSPALUM, L. (Pl. 13.)

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. (Πασπάλος, 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, decumbent or floating.)

1. P. flùitans, Kunth. Annual; leaves lanceolate, flat (3–8´´), broad; spikes numerous in a raceme, the rhachis somewhat projecting beyond the minute and slightly pubescent spikelets into a tapering point, scabrous on the back.—River-swamps, Va. to S. Ill., Mo., and southward. Sept., Oct.

2. P. Walteriànum, 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. setàceum, Michx. Culm ascending or decumbent (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 (½´´ wide) narrowly 2-rowed.—Sandy fields; common from E. Mass. to Ill., and southward. Aug.

4. P. læ̀ve, Michx. (Pl. 13, fig. 1–3.) Bright green, sparingly villous, rather stout; stems somewhat decumbent; 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.

4. ERIÓCHLOA, 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.—Coarse tufted grasses, with flat leaves, the spikes more or less scattered along a common peduncle, and the pedicels and rhachis of the spike usually pubescent or hairy (hence the name, from ἔριον, wool, and χλόα, grass).

1. E. polystàchya, HBK. Culms erect or decumbent, 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. PÁNICUM, L. Panic-Grass. (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. Italicum (now Setaria Italica), of uncertain origin and meaning.)

§ 1. DIGITÀRIA. Spikelets crowded 2–3 together in simple and mostly 1-sided clustered spikes or spike-like racemes, wholly awnless and pointless, 1-flowered; lower glume minute or obsolete or wanting; annual, often purplish.

P. sanguinàle, L. (Common Crab- or Finger-Grass.) (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 (1½´´ long); second glume half the length of the flower, the lower one small.—Cultivated and waste grounds. Aug.–Oct. (Nat. from Eu.)

§ 2. PANICUM 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 ½–1½´´ long; annuals except n. 4; leaves flat; sheaths flattened.

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

2. P. prolíferum, Lam. Culms usually thickish and rather succulent, branched, geniculate and ascending from a procumbent 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 ¼ the length of the upper, which is little longer than the flowering one.—Marshy river-banks and shores, especially if brackish, but also in the interior, from Mass. 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. capillàre, L. (Old-witch Grass.) (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 decumbent, geniculate and branched; in depauperate forms the spikelets only ¾´´, in the larger forms 1½´´ in length.

4. P. autumnàle, 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.

8. P. virgàtum, 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. amàrum, Ell. Culms (1½° 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 shores, Conn., Va., and southward. Aug., Sept.—The northern form (var. mìnus, Vasey & Scribn.) somewhat smaller than the southern.

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

[+] Sterile flower none; spikelets warty roughened.

10. P. verrucòsum, 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, ¾´´ long; lower glume ¼ 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 principal nerves (obscure or none in n. 17).

[=] Spikelets 1–1½´´ long.

11. P. xanthophỳsum, Gray. Culm simple, or at length branched near the base (9–15´ high); sheaths hairy; leaves lanceolate, very acute (4–6´ long by ½´ wide), not dilated at the ciliate-bearded clasping base, smooth except the margins, strongly 9–11-nerved; panicle long-peduncled, very simple, the appressed branches bearing a few roundish-obovate spikelets (about 1½´´ long); lower glume ovate, acutish, {1/3}–½ the length of the 9-nerved second.—Dry sandy soil, Maine to Penn., Wisc., Iowa, and northward; rare. June.—Yellowish-green; spikelets minutely downy; sterile flower sometimes staminate.

13. P. clandestìnum, L. (Pl. 13, fig. 6, 7.) Culm rigid (1–3° high), very leafy to the top, at length producing appressed branches, the joints naked; sheaths rough with papillæ bearing very stiff and spreading bristly hairs; leaves oblong-lanceolate from a heart-clasping base, very taper-pointed; lateral and usually also the terminal panicle more or less enclosed in the sheaths, or with the terminal one at length long-peduncled;—otherwise resembling n. 12; but the spikelets more ovoid, often smooth; the lower flower (always?) neutral.—Low thickets and river-banks, N. Eng. to Mich., Mo., and southward. June–Sept.

14. P. víscidum, Ell. Culms stout, upright or ascending, at length much branched, leafy to the top, densely velvety-downy all over, as also the sheaths, with reflexed soft and often clammy hairs, except a ring below each joint; leaves likewise velvety, lanceolate (½´ wide), 11–13-nerved; panicle spreading, the lateral ones included; spikelets obovate, 1 or 1½´´ long, downy; the roundish lower glume scarcely one fourth the length of the 7-nerved second one.—Damp soil, N. J. to Va., and southward. Aug.

15. P. scopàrium, Lam. Culms upright, at length much branched and reclining (1–2° long), roughish; leaves lanceolate (3–5´ long by {1/3}–½´ wide), rather faintly 9-nerved, hairy or smooth, fringed on the whole margin or next the base with long and stiff spreading hairs, the sheaths bristly throughout with similar hairs; panicle open, nearly simple, bearing few tumid-obovate hairy or smoothish spikelets about 1½´´ long; lower glume roundish, about half or a quarter of the length of the upper one. (P. pauciflorum, Ell.)—Wet meadows and copses, E. Mass. to Minn., west and southward. June, July.

16. P. commutàtum, Schultes. Rather slender, erect, 1–2° high, nearly glabrous; leaves lanceolate, acuminate (3–6´ long), the margins toward the base and the sheaths sparsely ciliate; panicle spreading, often short-peduncled; spikelets scattered, glabrous, oblong, acutish, little more than 1´´ long; lower glume ovate, often acute.—N. Y. to Fla.—A frequent variety with smaller spikelets (not 1´´ long) approaches the next, and has also been confused with P. dichotomum.—Ont. to Va. and southward.

[=][=] Spikelets less than 1´´ long.

17. P. nítidum, Michx. (Lam.?) Resembles the last; leaves rather thick and the principal nerves very obscure or none except at the base; panicle broad, more slender; spikelets smaller ({2/3}´´ long), broadly ovate and very obtuse; lower glume very obtuse. (P. sphærocarpon, Ell.)—N. Y. to Ga., and westward.

P. Crus-gálli, L. (Barnyard-Grass.) Root annual; culms stout, branching from the base (1–4° high); leaves lanceolate (½´ wide or more), rough-margined, otherwise with the sheaths smooth; spikes alternate (1–3´ long), crowded in a dense panicle; glumes ovate, abruptly pointed; glume of the neutral flower bearing a rough awn of variable length.—Varies greatly; sometimes awnless or nearly so; sometimes long-awned, especially in the var. híspidum, a very large and coarse form with the sheaths of the leaves very bristly.—Moist, chiefly manured soil; the variety in ditches, especially of brackish water; possibly indigenous. Aug.–Oct. (Nat. from Eu.)

6. SETÀRIA, Beauv. Bristly Foxtail Grass. (Pl. 13)

Spikelets altogether as in Panicum proper, and awnless, but with the short peduncles bearing below the joint of the spikelet solitary or clustered bristles resembling awns (but not forming an involucre). Inflorescence a dense spiked panicle, or apparently a cylindrical spike.—Annuals, in cultivated or manured grounds, with linear or lanceolate flat leaves. (Name from seta, a bristle.)

[*] Bristles single or in pairs, roughened or barbed downward.

S. verticillàta, Beauv. Spike cylindrical (2–3´ long, pale green), composed of apparently whorled short clusters; bristles short, adhesive.—Near dwellings. (Adv. from Eu.)

[*][*] Bristles in clusters, roughened or barbed upward.

S. glaùca, Beauv. (Foxtail. Pigeon-Grass.) (Pl. 13, fig. 1, 2.) Spike cylindrical, dense, tawny yellow (2–4´ long); bristles 6–11 in a cluster, much longer than the spikelets; perfect flower transversely wrinkled.—Very common, in stubble, etc. (Adv. from Eu.)

S. víridis, Beauv. (Green Foxtail. Bottle-Grass.) Spike nearly cylindrical, more or less compound, green; bristles few, longer than the spikelets; flower striate lengthwise and dotted.—Cultivated grounds. (Adv. from Eu.)

S. Itálica, Kunth. Spike compound, interrupted at base, thick, nodding (6–9´ long), yellowish or purplish; bristles 2 or 3 in a cluster, either much longer or else shorter than the spikelets.—Cultivated under the name of Millet, or Hungarian or Bengal Grass; rarely spontaneous. (Adv. from Eu.)

7. CÉNCHRUS, L. Hedgehog- or Bur-Grass. (Pl. 14.)

Spikelets as in Panicum, awnless, but enclosed 1 to 5 together in a globular and bristly or spiny involucre, which becomes coriaceous and forms a deciduous hard and rigid bur; the involucres sessile in a terminal spike. Styles united below. (An ancient Greek name of Setaria Italica.)

1. C. tribuloìdes, L. Annual; culms branched and ascending (1° high or less); leaves flat; spike oblong, of 8–20 spherical heads; involucre prickly all over with spreading and barbed short spines, more or less downy, enclosing 2 or 3 spikelets.—Sandy soil, on river banks, etc. Aug.—A vile weed.

8. AMPHICÁRPUM, Kunth. (Pl. 13.)

Spikelets jointed upon the pedicels, 1-flowered, oblong or ovoid, of two kinds; one kind in a terminal panicle, deciduous from the joint without fruit, although the flower is perfect; the other kind solitary at the extremity of slender runner-like radical peduncles (more or less sheathed toward the base), much larger than the others, perfect and fertile, subterranean, fertilized in the bud. Glumes 3, nearly equal, 5-nerved in the panicle, many nerved in the fertile spikelets; palet a little shorter; all becoming indurated and enclosing the very large grain. Stamens 3 (small in the radical flowers). Stigmas plumose, deep purple. (Name from ἀμφίκαρπος, doubly fruit-bearing.)

1. A. Púrshii, Kunth. Annual or biennial(?), erect, 1–4° high; leaves lanceolate, copious on the lower part of the culm, hispid, especially on the sheaths; panicle strict, naked; grain ovoid or oblong (2–3´´ long), terete.—Moist sandy pine-barrens, N. J. to Fla. Sept.

9. LEÉRSIA, Swartz. White Grass. (Pl. 7.)

Flowers crowded in one-sided panicled spikes or racemes, perfect, but those in the open panicles usually sterile by the abortion of the ovary, those enclosed in the sheaths of the leaves close-fertilized in the bud and prolific. Spikelets 1-flowered, flat, more or less imbricated over each other, jointed upon the short pedicels. Glumes 2, chartaceous, strongly flattened laterally or conduplicate, awnless, bristly-ciliate on the keels, closed, nearly equal in length, but the lower much broader, enclosing the flat grain. Palet none. Stamens 1–6. Stigmas feathery, the hairs branching.—Perennial marsh grasses; the flat leaves, sheaths, etc., rough upward, being clothed with very minute hooked prickles. (Named after John Daniel Leers, a German botanist.)

[*] Spikelets narrowly oblong, rather loosely crowded.

1. L. Virgínica, Willd. (White Grass.) Panicle simple; the spikelets closely appressed on the slender branches, around which they are partly curved (1½´´ long); stamens 2 (a third imperfect or wanting); glumes sparingly ciliate (greenish-white).—Wet woods; Maine to Minn., and southward. Aug.

2. L. oryzoìdes, Swartz. (Rice Cut-grass.) (Pl. 7, fig. 1–3.) Panicle diffusely branched; spikelets flat, rather spreading (2½–3´´ long); stamens 3; glumes strongly bristly-ciliate (whitish).—Very wet places; Mass, to Minn., and southward; common. Aug. (Eu.)

[*][*] Spikelets broadly oval, imbricately covering each other (2½–3´´ long).

3. L. lenticulàris, Michx. (Catch-fly Grass.) Smoothish; panicle simple; glumes very flat, strongly bristly-ciliate (said to close and catch flies); stamens 2; otherwise like the preceding.—Low grounds, Va., Ill., and southward.

10. ZIZÀNIA, Gronov. Water or Indian Rice. (Pl. 7.)

Flowers monœcious; the staminate and pistillate both in 1-flowered spikelets in the same panicle. Glumes 2, subtended by a small cartilaginous ring, herbaceo-membranaceous, convex, awnless in the sterile, the lower one tipped with a straight awn in the fertile spikelets. Palet none. Stamens 6. Stigmas pencil-form.—Large, often reed-like water-grasses. Spikelets jointed upon the club-shaped pedicels, very deciduous. (Adopted from ζιζάνιον, the ancient name of some wild grain.)

1. Z. aquática, L. (Indian Rice. Water Oats.) (Pl. 7, fig. 1–4.) Annual; culms 3–9° high; leaves flat, 2–3° long, linear-lanceolate; lower branches of the ample pyramidal panicle staminate, spreading; the upper erect, pistillate; lower glume long-awned, rough; styles distinct; grain linear, slender, 6´´ long.—Swampy borders of streams and in shallow water; common, especially northwestward. Aug.

2. Z. miliàcea, Michx. Perennial; panicle diffuse, ample, the staminate and pistillate flowers intermixed; awns short; styles united; grain ovate.—Penn. (?), Ohio, and southward. Aug.—Leaves involute.

11. TRÍPSACUM, L. Gama-Grass. Sesame-Grass. (Pl. 14.)

Spikelets monœcious, in jointed unilateral spikes, staminate above and fertile below. Staminate spikelets in pairs, sessile at each triangular joint of the narrow rhachis, both alike, 2-flowered, longer than the joints; glumes 4, coriaceous, the lower (outer) one nerved, the second boat-shaped, the upper with the palets very thin and membranaceous, awnless; anthers opening by 2 pores at the apex. Pistillate spikelets 2-flowered (the lower flower neutral), single and deeply imbedded in each oblong joint of the cartilaginous thickened rhachis, occupying a boat-shaped recess which is closed by the polished and cartilaginous ovate outer glume, the inner glume much thinner and pointed, the upper with the palets very thin and scarious, pointless. Styles united; stigmas very long (purple), hispid. Grain ovoid, free.—Culms stout and tall, solid, from very thick creeping rootstocks. Leaves broad and flat. Spikes axillary and terminal, separating spontaneously into joints at maturity. (Name from τρίβω, to rub, perhaps in allusion to the polished fertile spike.)

1. T. dactyloìdes, L. Spikes (4–8´ long) 2–3 together at the summit (when their contiguous sides are more or less flattened), and also solitary from some of the upper sheaths (when the fertile part is cylindrical); in var. monostàchyum, the terminal spike also solitary.—Moist soil, from Conn. to Penn. and Fla., near the coast, and from Ill. southward. Aug.—Culm 4–7° high; leaves like those of Indian Corn. This is one of our largest and most remarkable Grasses; sometimes used for fodder at the South.

12. ROTTBŒ́LLIA, L. f. (Pl. 16.)

Spikelets in pairs at each joint of a terete slender spike, awnless; one imperfect or rudimentary on a short and thick appressed pedicel; the other sessile and imbedded in an excavation of the joint of the rhachis, 1-flowered or rarely with a second staminate flower. Glumes 4, obtuse, the outer hard and cartilaginous, with a transverse depression next the base, the inner one boat-shaped and membranaceous, the 2 upper thin and delicate. Stamens 3. Styles 2.—Tall or coarse perennials, with rigid stems, and single cartilaginous spikes terminating the stem and axillary branches, chiefly subtropical. (Named for Prof. C. F. Rottboell, an excellent Danish botanist, who wrote much upon Gramineæ, Cyperaceæ, etc.)

1. R. rugòsa, Nutt. Culm flattish, 2–4° high; leaves linear; spikes 1–2´ long, the lateral ones on short clustered branches in the axils, often partly included in the sheaths of the leaves; sterile flower neutral; lower glume transversely rugose.—Low pine-barrens, from S. Del. (W. M. Canby) southward near the coast. Sept.–Oct.

13. ERIÁNTHUS, Michx. Woolly Beard-Grass. (Pl. 14.)

Spikelets spiked, in pairs upon each joint of the slender rhachis, one sessile, the other pedicelled, both 1-flowered, alike. Glumes 4, the 2 lower nearly equal, one 4–5-nerved, the other many-nerved; the 2 upper hyaline, one empty, the upper awned from the tip. Stamens 3. Grain free.—Tall and stout reed-like perennials, with the spikes crowded in a panicle, and clothed with long silky hairs, especially in a tuft around the base of each spikelet (whence the name, from ἔριον, wool, and ἄνθος, flower).

1. E. saccharoìdes, Michx. (Pl. 14, fig. 1, 2.) Culm (4–6° high) woolly-bearded at the joints; panicle contracted; the silky hairs longer than the spikelets, shorter than the awn; stamens 2. (E. alopecuroides, Ell.)—Wet pine-barrens, from N. J. and Ill. southward; rare. Sept., Oct.

2. E. brevibárbis, Michx. Culm (2–5° high), somewhat bearded at the upper joints; panicle rather open; silky hairs shorter than the spikelets.—Low grounds, Va., and southward.

14. ANDROPÒGON, Royen. Beard-Grass. (Pl. 14.)

Spikelets in pairs upon each joint of the slender rhachis, spiked or racemed, one of them pedicelled and sterile (staminate, pistillate or neutral), often a mere vestige, the other sessile, 1-flowered and fertile; lower glume the larger, coriaceous and nerved, blunt, the second carinate and acute, the 2 upper hyaline, the flowering glume awned from the tip. Stamens 1–3. Grain free.—Coarse, mostly rigid perennials, mostly in sterile or sandy soil; with lateral or terminal spikes commonly clustered or digitate; the rhachis hairy or plumose-bearded, and often the sterile or staminate flowers also (whence the name, composed of ἀνήρ, man, and πώγων, beard).

[*] Spikes digitate, thickish, short-bearded, the sterile spikelet staminate; stamens 3.

1. A. furcàtus, Muhl. (Pl. 14, fig. 1–3.) Tall, 3–4° high, rigid, the naked summit of the culm (and usually some lateral branches) terminated by 2–5 rigid spikes; spikelets approximate, appressed; hairs at the base of the fertile spikelet, on the rhachis and on the stout pedicel of the awnless staminate spikelet short and rather sparse; awn of fertile flower long and bent; leaves flat, roughish, the lower ones long. ("A. provincialis, Lam.")—Common in dry sterile soil. Aug.–Oct.

[*][*] Spikes with slender often zigzag rhachis, silky-villous.

[+] Single and scattered along the branches, with the silky hairs shorter than the flowers; sterile spikelet conspicuous but mostly neutral; the fertile triandrous.

2. A. scopàrius, Michx. Culms slender (1–3° high), with numerous paniculate branches; lower sheaths and narrow leaves hairy; spikes slender, scattered, mostly peduncled (1–2´ long), very loose, often purplish, silky with lax dull-white hairs; sterile spikelet awn-pointed or awnless; the fertile about half the length of its twisted or bent awn.—Dry ground. July–Sept.

3. A. marítimus, Chapm. Smooth and glaucous; culms ascending from creeping rootstocks, 1–1½° high; leaves rather rigid, divaricate, their compressed sheaths imbricated; panicle short; peduncles included within the conspicuous bracts; rhachis and pedicels copiously ciliate with spreading hairs; glumes larger, 3–4´´ long.—Sandy sea-coast; Cape May, and south to Fla.

[+][+] In pairs or clustered; the copious soft-silky hairs much longer than the flowers; sterile spikelet a small neutral rudiment (in n. 4 and 5), or altogether wanting on the very plumose-hairy pedicel; fertile flower monandrous, its awn capillary; leaves narrow, the lower or their sheaths often rather hairy.

4. A. argénteus, Ell. Smooth; culms rather slender (1–3° high); spikes in pairs (rarely in fours) on short mostly exserted and loosely paniculate peduncles, densely flowered (1–2´ long), very silky with long bright white hairs. (A. argyræus, Schultes.)—Md. to Va., near the coast, and southward.

15. CHRYSOPÒGON, Trin. (Pl. 14.)

Spikelets in pairs on the ramifications of an open panicle (those at the ends of the branches in threes), the lateral ones pedicellate, sterile or often reduced merely to their pedicels; only the sessile middle or terminal one fertile, its glumes coriaceous or indurated, sometimes awnless; otherwise nearly as in Andropogon. Stamens 3. (Name composed of χρυσός, gold, and πώγων, beard.)

1. C. nùtans, Benth. (Indian Grass. Wood-Grass.) Root perennial; culm simple (3–5° high), terete; leaves linear-lanceolate, glaucous; sheaths smooth; panicle narrowly oblong, crowded or loose (6–12´ long); the perfect spikelets at length drooping (yellowish or russet-brown and shining), clothed especially toward the base with fawn-colored hairs, lanceolate, shorter than the twisted awn; sterile spikelets small and imperfect, deciduous, or reduced to a mere plumose-hairy pedicel. (Andropogon avenaceus, Michx. Sorghum nutans, Gray.)—Dry soil; common, especially southward.

16. PHÁLARIS, L. Canary-Grass. (Pl. 13.)

Spikelets crowded in a clustered or spiked panicle, 1-flowered. Glumes 5, the third and fourth reduced to mere rudiments (a scale or a pedicel), one on each side, at the base of the flowering glume and palet, which are flattish, awnless and shining, shorter than the equal boat-shaped and keeled persistent empty glumes, finally coriaceous or cartilaginous, and closely enclosing the flattened free and smooth grain. Stamens 3.—Leaves broad, mostly flat. (The ancient name, from φαλός, shining, alluding to the shining seed.)

§ 1. PHALARIS proper. Panicle very dense, spike-like; glumes wing-keeled.

1. P. arundinàcea, L. (Reed C.) (Pl. 13, fig. 1, 2.) Perennial, 2–4° high; leaves flat (3–5´´ wide); glumes open at flowering, 3-nerved, thrice the length of the fertile flower; rudimentary glumes reduced to a minute hairy scale or pedicel.—Wet grounds; common, especially northward. June, July.—Var. pícta, the leaves striped with white, is the familiar Ribbon-Grass of the gardens. (Eu.)

17. ANTHOXÁNTHUM, L. Sweet Vernal-Grass. (Pl. 13.)

Spikelets spiked-panicled, 1-flowered. Glumes 5, the third and fourth empty, hairy, 2-lobed and awned on the hack, the flowering glume and palet small, hyaline and obtuse; basal glumes persistent, very thin, acute, keeled, the lower half as long as the upper. Squamulæ none. Stamens 2. Grain ovate, adherent. (Name compounded of ἄνθος, flower, and ἄνθων, of flowers. L.)

A. odoràtum, L. Spikelets (brownish or tinged with green) spreading at flowering-time; one middle glume bearing a bent awn from near its base, the other short-awned below the tip.—Meadows, pastures, etc. Low slender perennial; very sweet-scented in drying. May–July. (Nat. from Eu.)

18. HIERÓCHLOE, Gmelin. Holy Grass. (Pl. 13.)

Spikelets 3-flowered, open-panicled, the two lower (lateral) flowers staminate only, 3-androus, sessile, the carinate glumes often awned on the middle of the back or near the tip, the uppermost flower perfect, short-pedicelled, scarcely as long as the others, 2-androus, awnless. Basal glumes persistent, carinate, acute, somewhat 3-nerved, equalling or exceeding the spikelet.—Perennials; leaves flat. (Name composed of ἱερός, sacred, and χλόη, grass; these sweet-scented grasses being strewn before the church-doors on saints' days, in the North of Europe.)

1. H. boreàlis, Roem. & Schultes. (Vanilla or Seneca Grass.) (Pl. 13, fig. 1, 2.) Panicle somewhat one-sided, pyramidal (2–5´ long); peduncles smooth; staminate flowers with the glume mucronate or bristle-pointed at or near the tip; rootstock creeping.—Moist meadows, chiefly northward near the coast and along the Great Lakes. May.—Culm 1–2° high, with short, lanceolate leaves. Spikelets chestnut-color; the staminate flowers strongly hairy-fringed on the margins, and the fertile one at the tip. (Eu.)

2. H. alpìna, Roem. & Schultes. Panicle contracted (1–2´ long); one of the staminate flowers with its glume barely pointed or short-awned near the tip, the other long-awned from below the middle; lowest leaves very narrow.—Alpine mountain-tops, N. Eng., N. Y., and northward. July. (Eu.)

19. ARÍSTIDA, L. Triple-awned Grass. (Pl. 8.)

Spikelets 1-flowered, not jointed on the pedicels. Outer glumes unequal, often bristle-pointed; the flowering glume tipped with three awns; the palet much smaller. Otherwise much as in Stipa.—Culms branching; leaves narrow, often involute. Spikelets in simple or panicled racemes or spikes. Grain linear. All grow in sterile, dry soil, and all ours have the awns naked and persistent, and flower late. (Name from arista, a beard or awn.)

7. A. purpùrea, Nutt. Perennial; culms (1° high or less) densely tufted, spreading; leaves revolute and filiform, short; panicle loose, of rather few slender-pedicellate spikelets; lower glumes thin, 1-nerved, loose, the outer about half the length of the inner, which is 8–10´´ long; awns 2–4´´ long.—Minn. and Dak. to Tex.—Very variable.

8. A. purpuráscens, Poir. (Pl. 8.) Glabrous; leaves long, rather involute; spikelets in a (10–18´) long spiked panicle; lower glumes 1-nerved; awns much longer than the spikelet, the middle one about 1´ long.—Mass. to Mich., Minn., and southward; common.

9. A. lanàta, Poir. Tall and stout; leaves tardily involute, rough above, rigid; sheaths woolly; panicle (1–2° long) spike-like or more compound and open; glumes 1-nerved, 6–8´´ long; middle awn 1´ long.—Del. to Fla.

[*][*] Awns united below into one, jointed with the apex of the glume; root annual.

10. A. tuberculòsa, Nutt. Culm branched below (6–18´ high), tumid at the joints; panicles rigid, loose, the branches in pairs, one of them short and about 2-flowered, the other elongated and several-flowered; lower glumes (1´ long, including their slender-awned tips) longer than the upper, which is tipped with the common stalk (about its own length) of the 3 equal divergently-bent awns (1½–2´ long) twisting together at the base.—Sandy soil, E. Mass. to N. J.; also Wisc., Minn., and southward.

20. STÌPA, L. Feather-Grass. (Pl. 8.)

Spikelets 1-flowered, terete; the flower falling away at maturity (with the conspicuous obconical bearded and often sharp-pointed callus) from the membranaceous persistent lower glumes. Fertile glumes coriaceous, cylindrical-involute and closely embracing the smaller palet and the cylindrical grain, having a long and twisted or tortuous simple awn jointed with its apex. Stamens mostly 3. Stigmas plumose.—Perennials, with narrow involute leaves and a loose panicle. (Name from στύπη, tow, in allusion to the flaxen appearance of the feathery awns of the original species. In our species the awn is naked.)

[*] Callus or base of the flower short and blunt; lower glumes pointless.

1. S. Richardsònii, Link. Culm (1½–2° high) and leaves slender; panicle loose (4–5´ long), with slender few-flowered branches; lower glumes nearly equal, oblong, acutish (2½–4´´ long), about equalling the pubescent linear-oblong fertile one, which bears a tortuous awn 6–9´´ long.—Pleasant Mountain, near Sebago Lake, Maine, Mt. Marcy, N. Y., north shore of L. Superior, Mont., and northward.

[*][*] Callus pungently pointed, at maturity villous-bearded; flowering glume slender and minutely bearded at the tip; empty glumes taper-pointed.

2. S. avenàcea, L. (Black Oat-Grass.) (Pl. 8.) Culm slender (1–2° high); leaves almost bristle-form; panicle open; fertile glume blackish, nearly as long as the lower ones (about 4´´ long); the awn bent above, twisted below (2–3´ long).—Dry woods, S. New Eng. to Wisc., and southward.

3. S. spàrtea, Trin. (Porcupine Grass.) Culm rather stout (1½–3° high); panicle contracted; fertile glume linear, ¾–1´ long (including the long callus), pubescent below, shorter than the lanceolate slender subulate pointed greenish lower glumes; the twisted strong awn (3½–7´ long), pubescent below, rough above.—Plains and prairies, from Ill. and N. Mich. northwestward.