MONOCOTYLEDONES 213 



Distribution. — They are widely' distributed, but are chiefly 

 found in extra-tropical regions. Illustrative Genera : — Naias, 

 Willd, ; Zannichellia, Michel; Zostera, Linn. 



ProiJerties and Uses. — Their properties are of Httle impor- 

 tance. 



Order 34. Juncaginace.e, the Arrow-grass Order. — Cha- 

 racter. — Herbs, growing in marshes. Leaves with parallel 

 veins. Flowers hermaphrodite, whitish or greenish. Perianth 

 small, more or less scaly, inferior, in two whorls, each containing 

 three pieces. Stamens 6, perigynous, anthers usually extrorse. 

 Carpels 3 — 6, separate or more or less united; ovules 1 — 2. 

 Fruit dry, ultimately separating into as man}' parts as there are 

 carpels. Seeds attached to axile or basal placentas, exalbumi- 

 nous ; embryo straight, with a lateral cleft. This order is in- 

 cluded by Bentham and Hooher in Naiadacea^. 



Distribution and Numbers. — The plants of this order are 

 found more or less in nearly all parts of the world, but are most 

 abundant in temperate and cold regions. Illustrative Genera : 

 — Triglochin, Linn. ; Potamogeton, Linn. There are about 50 

 species. 



Properties and Uses. — Of little importance. 



Series 7. — Glumacece. 



Order 35. Eriocaulace^, the Eriocaulon or Pipe wort Order. 

 Ch a r a c t e r. — Aquatic or marsh plants. Lea ves clustered, linear, 

 usually grass-like. Flowers minute, unisexual, in dense heads, 

 each flower arising from the axil of a membranous bract. 

 Perianth membranous, tubular, 2 — 3-toothed or -lobed. Stamens 

 2 — 6 ; anthers 2-celled, introrse. Ovary superior, 2 — 3-celled. 

 Fruit dehiscent, 2 — 3-celled, 2 — 3-seeded. Seeds pendulous, 

 albuminous, hairy or winged ; embryo lenticular, at the end 

 of the albumen remote from the hilum. 



Distribution, Numbers, and Propei'ties. — Mostly natives of 

 tropical America and the North of Australia. One species is 

 f'omid in Britain, Eriocaulon septangulare. With. The order 

 contams about 200 species. Their properties are unimportant. 



Order 36. Desvauxiace.e, the Bristlewort Order. — Charac- 

 ter. — Small sedge-like herbs, with setaceous sheathing leaves. 

 Flo2oers glumaceous, enclosed in a terminal spathe. Glumes 1 

 or 2. PalecB none, or 1 or 2 scales parallel with the glumes. 

 Stamens 1 or very rarely 2 ; anthers 1-celled. Carpels 1 — 18, 

 distinct or partially miited, with 1 stigma and 1 pendulous ovule 



