304 THE FLORA. 



Oedeh CXXXII. TYPHACE^. Typhads. 



Herls growing in marshes and ditches, with rigid, sword-shaped leaves ; 

 floicers monoecious, arranged on a spadix or in heads with no spathe ; 

 Ijerianth of a few scales, or a tuft of hairs, or ; stamens 1-4, slender ; 

 ooary 1-OTuled, nut-like and 1-seeded in fruit. — Comprises 2 genera. 



Analysis of the Genera. 



§ Cat-tail. Reed-mace. Spadix long-C}''Iindric, brownish green, the sterile flowers above, 

 the fertile innumerable, packed solid in the lower part. Stem with its terminal spa- 

 dix 3-4f., the leaves 4-5f. long. Ttpha. 



§ Burr-reed. Spadices or globular heads many, the lower fertile ; pistils sessile, each 

 with 3-6 scales for a calyx. Upper heads staminate. Sparga'nium. 



Okder CXXXIII. NAIADACE^. Naiads. 



Water plants, with sheathing petioles or stipules, and jointed stems ; 

 flowers often perfect, with a perianth, or imperfect and naked ; with 

 stamens definite, ovaries free, sessile, and 1-sceded Indehiscent/rz^iY. • 



The Naiads grow in rivers, lakes, or seas. They have linear, grass-like leaves, and 

 some of the Pondweeds have broad or oval leaves beside. 



Potamoge'ton {Pondweed) is the principal genus. Its flowers are perfect, greenish, 

 clustered on spike-lilce sp:idicc'S which arise just above tlie water while in bloom. The 

 stamens, sepals, and ovaries are each 4, and the fruit 4 achenia. We have about 20 species, 

 all in fresh water. Eight of these have two kinds of leaves; the submersed linear, the 

 floating elliptical. The other species have all their Ivs. submersed and linear. (See 

 Botanist and Florist.) 



COHORT YI. 



FLORIDE^, OR THE FLOWERING ENDOGENS. 



Order CXXXIV. HYDEOCHAEIDACE^. Frogbits. 



Aqvatic herbs with regular, imperfect flowers growing from a spathe ; 

 2Jerianih 3- or 6-parted, the inner segments petaloid; stamens 3-12; 

 ovary adherent, 6-9-celled; fi'uit indehiscent, many-seeded. 



