488 



ILLUSTRATIONS OF THE NATURAL ORDERS. 



quently the embryo) curved or doubled upon itself. Triglochin and 

 Scheuchzeria chiefly constitute the suborder JuNCAGiNEif; ; where 

 the seed and embryo ai-e straight, and the petals (if present) are 

 greenish like the calyx. Slightly acrid plants, and some of them 

 astringent. 



935. Ord. ButomaceiE, represented by Butomus, the Flowering- 

 Eusli of Europe, and three small tropical genera, is a form of the 

 last with many ovules attached to the whole face of the carpels : 

 these are separate or combined. Some have a milky juice. 



936. Ord. Ilydrocharidaceffi {Frog's-bit Family) consists of a few 

 aquatic herbs, with dicecious or polygamous regular flowers on scape- 

 like peduncles from a spathe, and simple or double floral envelopes, 

 which in the fertile flowers are united in a tube, and adnate to the 

 1 — 6-celled ovary, more commonly one-celled with three parietal 

 placentas. Seeds numerous, without albumen. — Fx. Llmnobium, 

 Vallisneria, Anacharis. 



937. Ord. OrchidaceiB (Orchis Family). Herbs, of varied aspect 

 and form ; distinguished from the other orders with an adnate ovary, 

 and from all other plants, by their irregular flowers, with a perianth 



FIG. 1220. Raceme or ppike of Triglochia palustre. 1221. Enlarged flower. 1222. A petal 

 and stamen. 1^3. The club-shaped capsule. 1224. A magnified seed, exhibiting the rhaphe 

 and rhalaza. 1225. Embryo of the same. 1226. Vertical section of the same, bringing the 

 plumule to Tiew. 1^7. Cross-section (more magnified), showing the cotyledon wrapped 

 around the plumule. 



FIG. 1228. Leaf, and 1229, flower, of Alisma Plantago. 1230. More enlarged flower, with 

 the petals removed. 1231. Carpel, with the ovary divided, showing the doubled ovule. 1232. 

 Verticjil section of the germinating seed of Alisma Dama^onium ; a, the cotyledon ; 6, the plu- 

 mule ; c, the protruding radicle. 



