472 A TEXT-BOOK OF BOTANY. 



grains are more or less translucent and horny, they have a 

 wrinkled or shrivelled surface. The cells of the endosperm con- 

 tain gum-like substances and a relatively small number of nearly 

 spherical starch grains from 4 to 10 /i. in diameter. 



Broom corn. (Andropogon anindinaccus vidgaris) is a plant 

 which is cultivated for the panicles or seed heads, which are used 

 in the manufacture of brooms. Tliis plant differs from the other 

 species of Andropogon in that the branches of the panicles are 

 longer, straighter, and stronger, forming a so-called *' brush." 



Quite a number of the grasses contain odorous principles, as 

 Andropogon citratus, which yields lemon-grass oil; A. Schocnan- 

 tlius, which yields gingergrass or geranium-grass oil; A. sqitar- 

 rosus, the rhizome of which is known as Vetiver. Coumarin is 

 found in \^anilla grass {Anthoxanthiim odoratmn) and white or 

 Dutch clover {Hierochlcr odorata). Some species of Stipa are 

 used in the manufacture of paper (Alfa or Esparto) in North 

 Africa and Spain. 



b. CYPERACE^ OR SEDGE FAMILY.— These plants are 

 all herbaceous, the majority being perennial (seldom annual). 

 The rhizomes are mostly sympodial (being monopodial, however, 

 in certain Carices), and the stems are mostly solid and triangular, 

 without swollen nodes. The leaves are grass-like, generally 

 arranged in three rows, and the sheath is closed, being mostly 

 without ligules. The flowers may be hermaphrodite or unisexual, 

 sometimes dioecious, and arranged in spikes or racemes. The 

 perianth is wanting or only represented by 6 bristles, or by an 

 indefinite number of hairs. The number of stamens is 3, with the 

 anthers attached by their bases to the filament. The gynaecium 

 consists of 2 to 3 carpels, with one style divided into 2 or 3 

 branches, and provided with papill?e. The fruit is a nut, whose 

 seed is generally united with the pericarp. The embryo is small 

 and is centrally situated at the base of the seed, being surrounded 

 by the endosperm. On germination, the cotyledon is freed from 

 the seed. 



A number of the sedges yield food products, as the rhizomes 

 of Cyperus esculentns and Eleocharis tiiherosa, the latter of which 

 is used in the manufacture of starch in China and India. Quite 

 a number of species of Scirpus, Cyperus, Carex, etc., are used in 



