ALISMACE^ — BUTOMACE^. 623 



fever, hypogynous, some of them occasionally abortive or deformed ; 

 anthers introrse. Ovary 3-celled ; ovules few in each cell ; style 1 ; 

 stigma 1. Fruit a 2-3-celled, 2-3-valved capsule, with locijioidal 

 dehiscence. Seeds often in pairs, with a lateral and linear hilum ; 

 embryo pulley-shaped, antitropal, in a cavity of fleshy albumen, remote 

 from the hilum. — Herbs with flat narrow leaves, which are usually 

 -sheathing at the base. Natives chiefly of warm climates. Some have 

 fleshy rhizomes, which are used for food. Tradescantias, Spider-worts, 

 have moniliform staminal hairs, in which a microscopic movement of 

 protoplasmic granules is seen (fig. 246, p. 153). Genera, 17 ; species, 

 264. Examples — Commelyna, Tradescantia, Mayaoa. 



Order 207. — Alismace-s;, the Water-plantain' Family. (Mono- 

 Sypog) Perianth in 6 divisions and 2 verticils ; outer whorl usually 

 herbaceous ; inner usually petaloid ; sometimes the perianth is want- 

 ing. Stamens definite or 00, hypogynous ; anthers introrse or extrorse. 

 Ovaries, 3, 6, or more, distinct or united ; ovules erect or ascending, 

 solitary or in pairs ; styles and stigmas equal to the number of car- 

 pels. Fruit of several dry, indehiscent carpidia. Seeds 1-2 in each 

 carpel, exalbuminous ■ (fig. 621, p. 342); embryo straight, or curved 

 like a horse-shoe ; radicle next the hUum. — Plants growing in flowing 

 or stagnant water, usually with a creeping rhizome, parallel-veined 

 leaves, and hermaphrodite or unisexual flowers. Natives both of 

 tropical and temperate regions. The limits of the order are not well 

 defined. It has been divided into two sub-orders : — 1. Alismees, inner 

 perianth petaloid, anthers introrse, embryo curved or hooked. 2. 

 Juncaginese, inner perianth herbaceous, sometimes perianth 0, anthers 

 extrorse, embryo straight, plumule coming through a slit in the em- 

 bryo (fig. 600, p. 336). They have few important properties. Some 

 are a^jrid, others have'eatable rhizomes. Various Brazilian Sagittarias 

 are very astringent ;■ their expressed juice being employed in the pre- 

 paration of ink. There are 10 known genera and about 50 species. 

 Examples — Alisma, Sagittaria; Triglochin, Scheuchzeria, Triuris. 



Order 208. — BuTOMACEiE, the Flowering-rush Family. (Mono- 

 Eypog.) Perianth of 6 parts, in 2 verticils (fig. 415, 2, p. 238) ; 

 outer usually herbaceous ; inner petaloid. Stamens definite (fig. 415, 

 2, eo, ei, p. 238), or 00, hypogynous. Ovaries, 3, 6, or more, distinct 

 or united, 1-celled (fig. 415); ovules 00; stigmas simple, as many 

 as the carpels. Fruit consisting of several follicles, which are either 

 distinct (fig. 427, p. 243) and beaked, or combined. Seeds 00, minute, 

 attached to the whole inner surface of the pericarp (fig. 428, p. 243), 

 ■ exalbuminous ; embryo often curved like a horse-shoe ; radicle next 

 the hilum. — Aquatic plants, often lactescent, with parallel-veined 

 leaves, and frequently umbellate flowers. They are chiefly found in 

 northern countries, and some of them have acrid and bitter properties. 

 Butomus umbellatus, Flowering-rush, is the only British plant in the 



