Special M orphology and Classtfication. 345 
which is called the scucellum (Fig. 461, Iv.) ; [though the scutellum is 
by some considered an outgrowth of the axis]. The Grasses constitute 
one of the largest orders in the 
vegetable kingdom, and are uni- 
versally distributed, but form 
meadows only in the temperate 
zone. Many genera are culti- 
vated for the sake of the nutri- 
ment contained in the seed, and 
form our cereal crops. Among 
these are wheat Z7iticum vul- 
gare, spelt Z. spelta, rye Secale Nay 
cereale, barley Hordeum vulgare, yy. 462.—Seed of Fic. 463.—Outer palez 
hexastichon, and other species, Dactylis glome- of the two barren 
. . . rata, with ter- flowers of a spikelet 
various species of oat Avena, minal awn. of Axthoxanthum; 6b 
millet Panicum  multaceum,. witha straight, a with 
: . : a bent dorsal awn. 
maize or Indian corn Zea Mais, 
rice Oryza sativa, and Egyptian millet Sorghum vulgare. The seeds 
of many species, especially wheat, contain gluten (protein) in addition . 
tc starch. Sugar occurs in the stem of most Grasses, but chiefly in the 
sugar-cane, Saccharum officinarum. Among officinal products are 
the rhizome of the couch-grass, Z7iticum repens. Among the more 
serviceable meadow-grasses are Anthoxanthum odoratum, Alopecurus 
pratensis, Phleum pratense, Agrostis vulgaris, FHolcus lanatus, Avena 
fiavescens and pubescens, Briza media, Poa annua, trivialis, and pra- 
tensis, Dactylis glomerata, Cynosurus cristatus, Festuca ovina, pratensis, 
rubra, and elatior, Bromus mollis, and Lolium perenne. ‘The largest > 
species is the East Indian bamboo, Bamébusa arundinacea (Fig. 464), 
30 to 60 feet high. [Important genera: —Andropogon, Panicum, 
Digitaria, Setaria, Zizanta, Oryza, Arthoxanthum, Phalaris, Zea, 
Coix, Phleum, Alopecurus, Agrostis, Milium, Macrochloa, Stipa, Cal- 
amagostis, Arundo, Phragmites, Ammophila, Cynodon, Spartina, Aira, 
Arrhenatherum, Avena, Holcus, Poa, Glyceria, Briza, Melica, Molinia, 
Dactylis, Cynosurus, Festuca, Bromus, Bambusa, Lolium, Triticuna, 
Elymus, Nardus, Hordeum, Secale, Sorghum, Saccharum. | 
Order 2, CYPERACE#. Perianth absent or consisting of bristles, 
rarely scales, or of asheathing bract; anthers basifixed; fruit compressed 
or trigonous ; embryo at the base of endosperm; stem usually solid and 
trianeular ; leaf-sheaths entire. Perennial plants of grass-like habit, 
often with creeping underground tuberous rhizomes (Fig. 465). ‘rhe 
aérial portion of the stem is, with the exception of the inflorescence, un- 
branched, unseptated, and usually triangular; the leaves are all radical, 
