Herbs, rarely woody or arborescent, with (mostly) hollow, jointed culms; with leaves alternate, distychous, on tubular sheaths split down to the nodes, and a ligule (stipules) of membranous texture where the leaf joins the sheath. Flowers in little spikelets of 1 or several, with glumes distychously arranged, and collected into spikes, racemes or panicles. Glumes, the lower pair of scales in the spikelet, alternate, enclosing the fls. Pales (palas) the outer pair of scales of each particular flower, unequal. Scales (perianth) usually 2 or 3, minute, hypogynous, distinct or united. Sta?nens 1 - 6, commonly 3, anthers versatile, of 2 distinct cells. Ovary simple with 1 ascending ovule, 2 styles and 2 feathery stigmas. Fruit a caryopsis. Embryo lateral, at the base of the farinaceous albumen.

Genera 300, species about 3S00, universally diffused throughout the world, baring no other limits than those that bound vegetation in general. But the species and their characters are widely different in different climes. In temperate zones the grasses clothe a large portion of the earth's surface with a compact, soft, green, carpet-like turf; but in tropical regions this beautiful grassy turf disappears and the grasses become larger, more isolated like other plants, fewer in the number of individuals, with broader leaves and more showy flowers.

Properties. - This family doubtless contributes more to the sustenance of man and beast than all others combined. Its sweet and nutritious properties reside both in the farinaceous albumen at the seed and in the herbage. No poisonous or even suspicious herb is found anions them, with the single exception of Lolium temulentum. The poisonous and medicinal Ergot or Spurred Rye is only a parasitic fungus, and therefore forms no exception to this remark. The stems of many grasses contain sugar, as the Maize and Sugar Cane. Silex is also a frequent ingredient. To this Order belong the common grains. Maize, Wheat. Rye, Rice, Barley, Oats, etc. The most important of the cultivated grasses are Phleum or Timothy grass, several kinds of Poa, Agrostis, Alonecurus, Festuca, Aira, Panicum, China, Briza, etc

FIG. 721. Agrostis alba; all flowered spikelet; a, the two glumes

FIG. 721. Agrostis alba; all flowered spikelet; a, the two glumes. 2. A flower, with the two paleae, three stamens and two plumo«s stigmas. 3. Leersia oryzoides; a flower removed from its glumes, showing its 2 hypogynous scales, three stamens and ovary with the two stgma-. 4. Phleum pratense; a l-flowered spikelet; a, glumes; b, truncate palea; etc. 5. Polypogon; a l-flowered spikelet; glumes and lower palea' awned. 6. Holcus lanatus; a two-flowered spikelet; a. glumes; b. the two flowers (upper staminate). 7. Poa pratensis; a 4-flowered spikelet; a, the two glumes; b, a single flower, with two paleae, etc. 8. Festuca duriuscula; a 5-flow-ered spikelet; a, two glumes; b, a single flower. 9. The caryopsis of Hordeuin, showing the embryo at the base of the copious albumen.

Tribes And Genera

§ Spikelet 1-flowered with no apparent rudiment of a second fl. (2)

§ Spikelet 2-flowered, one of the fls. sterile or rudimentary. (7)

§ Spikelet 3-flowered, the 2 lower (lateral) fls. sterile or rudimentary, (i).................................

Tribe

6

§ Spikelet 2 - ∞-flowered, 2 or more of the fls. perfect. (9)

2 Inflorescence paniculate. (3)

2 Inflorescence strictly spicate, spikes equilateral. (5)

2 Inflorescence strictly spicate, spikes unilateral. (6)

3 Glumes none (or minute and the stamens 6). (a)........................

Tribe

1

3 Glumes present, at least 1 conspicuous. (4)

4 Pales of the flower thin and soft, often awned. (b)......................

Tribe

2

4 Pales of the flower coriaceous, - tipped with awns. (f)..................

Tribe

4

- awnless. (g).............................

Tribe

5

5 Spikes cylindric, the spikelets condensed all around. (e).........................

Tribe

3

5 Spikes prismatic, spikelets sessile in rows. (v).......................................

Tribe

9

6 Spikelets rounded on the back, appressed to the rachis. (g).................

Tribe

5

6 Spikelets acutely keeled on the back, imbricated on cach other, (x)

Tribe

10

7 Upper fls. of the spikelet abortive. - Fls. in unilateral spikes, (x).................

- Fls. paniculate. (k)..............................

Tribe

7

7 Lower flower of the spikelet abortive. (8)

8 Pales coriaceous, firmer in texure than the gls. Paniculate, (g).....

Tribe

5

8 Pales memberanous, thinner than the glumes. Spicate. (bb)...................

Tribe

11

9 Flowers in 2 or 4-rowed, - equilateral spikes. (v)..............................

Tribe

9

- unilateral spikes. (x)..................................

Tribe

10

9 Fls. in panicles more or less diffuse. (10)

10 Pale awned at the tip orawnless. (n)..........................

Tribe

8

10 Pale awned on the back or below the tip. (k)...........

Tribe

7

Tr. 1. ORYZEae. (Spikelets 1-flowered, panicled. Gls obsolete. Stam. 1 - 6.)

a Flowers perfect, flattened laterally, awnless. - Gl. 0. Stam. 2 or 3.....

LEERSIA.

1

- Gl. minute. Stam. 6.....

ORYZA.

2

a Flowers monœcious, convex on the back, awned. Stamens 6.......................

ZIZANIA.

3

Tr. 2. AGROSTIDEae. (Spikelets 1-flrd., panicled. Gl. and pales thin. Grain free.)

b Fls. surrounded at base with a tuft of long, silky hairs......................

CALAMAGROSTIS.

9

b Fls. naked or thinly bearded at base, (c)

c Glumes both long-awned and longer than the awned pales...............

POLYPOGON.

8

c Glumes both awn-pointed (or minute and the pale awned)............

MUHLENBERGIA.

7

c Glumes awnless, conspicuous, (d)

d Pale stalked in the glumes, awned on the back, monandrous.....

CINNA.

6

d Pale sess. in the gls. 3-androus, - acute, awnless. Gls. shorter...

SPOROBOLUS.

5

- obtuse, often awned on the bad

Agrostis

4

TR. 3. PHLEOIDEae. - e Gls. united at base, awnless. Pale 1, awned......

Alopecurus.

10

- e Gls. distinct, mucronate. Pales 2, awnless.......

PHLEUM.

11

Tr. 4. STIPACEae - f Awn of the flower simple, straight, deciduous.......

ORYZOPSIS.

14

- f Awn of the flower simple, straight, deciduous...............

STIPA.

13

- f Awn of the flower triple or 3-parted.................

ARISTIDA.

12

TR.. 5. PANICIEae (Spkl. 2-fl., lower fl. abortive. Gls. very unequal.Tribes And Genera 2435 Pale coriaceous.)

g Spkl. apparently 1-flowered, the lower glume wanting and the single abortive pale supplying its place. - Fls. spicate, unilateral........................

PASPALUM.

15

- Fls. diffusely panicled, all alike...................

MILLIUM.

16

- Fls. paniculate, 2 sorts, one under ground.......

AMPHICARPUM.

17

g Spkl. evidently 2-flowered, both gl. present, abort, fl. neutral orTribes And Genera 2436 . (h)

h Fls. paniculate, - without awns or spines. Gl. very unequal....................

PANICUM.

18

- with the glumes and pale coarsely awned......................

Oplismenus.

19

h Fls. spike - paincled. - each with an invol. of awned pedicels...............

SETARIA.

20

- each with a hardened, burr - like invol.................

CENCHRUS.

21

Tr. 6. PHALAEIDEae. - i Sterile fls. 2 minute rudiments. Panicle spicate............

PHALARIS

22

- i Sterile fls. 2 awned pales. Panicle spicate..........

Anthoxanthum.

23

- i Sterile fls. both 2-valved,Tribes And Genera 2437 . Panicle, open..........

HlEROCHLOA.

24

Tr. 7. AVENEae. (Spkl. 2 - ∞-flrd., panicled. Gls. large. Tale awned below the tip.)

k Spikelet with 1 perf. flower and 1 awned stam. flower - above............................

HOLCUS.

25

- below.....

§ ARRHENATHERUM.

28

k Spikelet with definitely 2 perfect fls. Pale subentire. awn dorsal..........................

AIRA.

26

k Spikelet with 2 or more perfect fls. Pale 2-tootbed at apex, (m)

m Awn between the 2 teeth, twisted; glumes very large........................

DANTHONIA.

27

m Awn dorsal below the middle (except in the cultivated Oat)............

AVENA.

28

m Awn dorsal above the middle. - Fls. 2 - 5. Teeth cuspidate...........

TRISETUM.

29

- Fls. 5 - ∞. Teeth acutish.........

BROMUS.

30

Tr. 8. FESTUCACEae. (Spkl. 2 - ∞-flrd. panicled, awnless, or the lower pale tipped with a straight bristle or awn. Glumes 2.)

n Glumes definitely 2, all the lower fls. of the spkl. perfect, (o)

n Glumes several, indefinite, the lower fls. abort, and glume-like, (p)

o Lower pale 3-cuspidate at apex, fringe-bearded below, (q)

o Lower pale mueronate or awn-pointed (except in 1 Festuca). (r)

o Lower pale obtuse or acute, not at all awned. (s)

q Upper pale naked, lower with 3 cusps and 2 teeth..........................

TRICUSPIS.

31

q Both pales fringed, lower with 1 awn and 2 cuspidate teeth.........

URALEPIS.

32

r Glumes and pales keeled, - herbaceous, 5-veined. Fls. glomerate

DAOCTYLIS.

83

- membranous, 3-veined. Pan. spicate

KŒLERIA.

34

r Gls. and pales rounded on the back, - both coriaceous. Grain free

DlARUHENA.

35

- pale papery, gr. adherent..

Festuca.

36

s Spkl. 2 - 3-flrd. with some abortive terminal fls. Pale papery, not keeled, (t)

t Upper glume broad-obovate, shorter than the flower.....................

EATONIA.

37

t Upper glume oblong, 7-9-veined, longer than the fls......................

MELICA.

38

s Spikelets 2 - 50-flowered, all perfect. Tales usually thin, (u)

u Lower pale keeled, 3-veined, membranous like the glumes.....

ERAGROSTIS.

89

u Lower pale keeled, 5-veined, usually cobwebbed at base...................

POA.

40

u Lower pale convex-keeled, obscurely 9-vcincd. Pan. spiked...

BRYZOPYRUM.

41

u Lower pale convex, 7 ( - 5)-veined, never webbed at base...............

GLYCERIA.

42

u Loer pale convex-ventrocous, cordate, obscurely veined...............

BRIZA.

43

p Herbaceous. - Fls. glabrous, awnless, falcate-pointed................

UNIOLA.

44

- Fls. silky-villous at base. Tall, stout....................

PHRAGMITES.

45

p Woody, tall (the flowering branches low). Fls. short-awned,

Arundinaria.

46

Tr. 9. HORDEACEae. (Spkl. 1 - 10-fld., sessile, alternate in a spike. Rachis jointed.)

v Spikes sveral. Spike. solitary at each joint, 1-flowered.....................

LEPTURUS.

47

v Spikes single. - Spikelets 1-flowered, 3 at each joint..........................

HORDEUM.

48

- Spikelets 2 - ∞ -flowered, - several at each joint ..........

ELYMUS.

49

- 1 at each joint, (w)

w Glume 1, in front of the spikelet which is edgewise to rachis...................

LOLIUM.

50

w Glumes 2, opposite. - Spikelet 3 - ∞- flowered.............................

TRITICUM.

51

- Spikelet 2-flowered.....................................

SECALE.

52

Tr. 10. CHLORIDEae. (Spkl. in 1-sided jointlessspikes, 1 - ∞-flrd. Up. fl. abortive.)

x Spikes very slender, many, in an equilateral raceme, (y)

y Spikes raceme-like. Spkl. with several perfect fls...............................

LEPTOCHLOA.

53

y Spikes with sessile, 2-flowered spkl., 1 fl. a rudiment............

Gymnopogon.

54

x Spikes slender, several, digitately arranged above, or, in No. 55, axillary, (z)

z Spikelets with 1 perfect flower, - awnless, globular, no rudiment.

MANISURUS.

55

- awnless, oblong, with a rudimen

Cynodon.

56

- awnless, oblong, with a rudiment.....

EUSTACHYS.

57

- awned, glume 3-lobed...................

ELEUSINE.

58

z Spikelets with several perfect flowers. - Fls. awnless..........................

Dactyloctemum.

59

x Spikes thick and dense, 1 - ∞. Spikl. with 1 perfect flower, (aa)

aa Spikes several or many. - Flower with no rudiment.........................

SPARTINA.

60

aa Spikes 1, few, or many. Flower with a terminal rudiment............

BOUTELOUA.

61

aa Spikes solitary, recurved. Awns terminal and dorsal.....................

CTENIUM.

62

Tr. 11. SACCHARIEae. (Spkl. in pairs or 3s, 2-flowercd, the lower flower abortive.

Fertile pales thinner than the glumes, except in No. 66.)

bb Fls. (the fertile) imbedded in the cavities of glabrous, jointed spikes, (cc)

cc Spikes monœcious,Tribes And Genera 2438 abortive, Tribes And Genera 2439 below enveloed in husks..

TRIPSACUM.

63

cc Spikes monoeciousTribes And Genera 2440 above panicled, Tribes And Genera 2441 below enveloped in husks.

Zea.

64

cc Spikes uniform, - terete. The pedunculate spkl. abortive......

ROTTBŒLLIA.

65

- compressed. Both spikelets fertile............................

STENOTAPHRUM.

66

bb Fls. not imbedded, spicate or panicled, mostly long-bearded, (dd)

dd Both spikelets of each pair fertile. - Lower fl. awned......................

ERIANTHUS.

67

- Flowers awnless...........................

SACCHARUM.

68

dd Only one spikl. of each pair fertile. - Fls. and rachis hairy.....

Andropogon.

69

- Fls. and rachis smoothish...

SORGHUM.

70

dd The lower spikelet on each spike, fertile, in a bony shell......................

COIX.

71

1. LEER'SIA, Soland. Cut Grass. False Rice. (In honor of John Daniel Leers, a German botanist.) - Spikelets 1-flowered,Tribes And Genera 2442 , flat; glumes none; palea; boat-shaped, compressed, awnless, bristly-ciliate on the keel, nearly equal in length but the lower much broader, enclosing the free, flat grain (caryopsis). - Tribes And Genera 2443 Swamp grasses, with flat, retrorsely rough-edged leaves, and the fls. racemous-paniculate, somewhat secund, jointed to the pedicels.

1 D. oryzoides Swartz Cut Grass. Culm retrorsely scabrous, 3 - 5f high; lvs-. lanceolate, carinate, the margin very rough backwards; sheaths also very rough with retrorse prickles; panicle much branched, diffuse, sheathed at the base; spikelets spreading; palece full 2" long, ciliate on the keel, white, compressed and closed; sta. 3. -Tribes And Genera 2444 A very rough grass, common in swamps, by streams, etc., U. S. and Can. Aug.

2 L. Virginica Willd. White Grass. Culm slender, branched, geniculate or decumbent at base, 2 - 3f long, nodes retrorsely hairy; lvs. lance-linear, roughish; sheaths roughish backwards, striate; panicle simple, at length much exserted, the lower branches diffuse; fls. pedicellate, in short, appressed, flexuous racemes; lower palea scarcely more than l" long, green-veined, mucronate; sta. 1 - 2. -Tribes And Genera 2445 Damp woods, U. S. and Can. Aug.

3 L. lenticularis Michx. Catch-fly Grass. Plant smoothish; culm erect, 2 - 4f high; panicle erect; fls. large, roundish-oval, near 3" diam., imbricated; sta. 2; pales with the keel and veins ciliate. -Tribes And Genera 2446 Wet places, Ct. (Eaton) to I11. and S. States. Not common. Said to catch flies by the sudden closing of its pales.

2. ORY'ZA, L. Rice. (Gr.Tribes And Genera 2447 , from the Arabic, Eruz.) - Spikelets 1-flowered, Tribes And Genera 2448 ; glumes 2, very small, cuspidate; pales 2, boat-shaped, flattened, the lower one broader and mostly tipped with a straight awn; stam. 6; stigmas with branching hairs; grain oblong, free, smooth, enveloped in the pales. - Mostly Tribes And Genera 2449 , Fls. in a branching panicle of racemes. Spikes hispid, jointed to the pedicel.

O. sativa L. Culm 2 - 4f high, striate; lvs. long, rough, lance-linear; ligule long (near 1), erect, pointed; panicle with erect branches, 6 - 9'in length; outer pale strongly 5-veined or keeled, hispid-ciliate and commonly tipped with a short awn. - Extensively cultivated in the S. States, both in upland meadows and in low inundated grounds. The former variety - the upland rice, is usually awnless, the latter is awned. A most important Cereal. \ Asia.