EXOGENOUS OR DICOTYI.EDONOVS PLAXTS. 



395 



The plants yield a resinous acrid juice, and a bittei-, balsamic ex- 

 tractive matter. 



762. Ord. ElalinacefC {Waterwort FamihJ). Small annual weeds 

 with membranaceous stipules between the opposite leaves, and mi- 

 nute axillary flowers. Sepals and petals three to five. Stamens as 

 many or twice as many as the petals, distinct. Capsule 2 - 5-celled, 

 septicidal or septifragal ; the numerous seeds attached to a persist- 

 ent central axis. Albumen none. — Ex. Elatine is the type of this 

 order, containing a few insignificant weeds. 



763. Ol'd. Caryopliyllacea; {Pink Famlhj). Herbs, with opposite 

 entire leaves ; the stems tumid at the nodes. Flowers regular. 

 Calyx of four or five sepals. Corolla of four or five petals, or 

 sometimes wanting. Stamens as many, or commonly twice as many, 

 as the petals, sometimes reduced to two or thi-ee. Styles two to 

 five, stigmatose down the inside. Ovary mostly one-celled, with a 

 central or basilar placenta, forming a pod in fruit. Embryo periph- 

 eric, curved or coiled around the outside of mealy albumen (Fig. 

 620, 621, 726). — There are five principal suborders, viz. : — 



7G4. Sllbord. Sileiieae {Pink Family proper) ; in which the sepals 

 are united into a tube, and the petals (mostly convolute in osstiva- 

 tion) and stamens are inserted on the stipe of the ovary, the former 

 with long claws (Fig. 432, 449), and there are no stipules. — Ex. 

 Silene, Dianthus (Pink, Carnation). 



7G5. Suboi'd. AlsineCB {CIdckweed Family)', in wliich there are no 



FIG. 720. Ilj'pericum perforatum (St Johnswort). 721. Its tricarpellary pistil. 722. 

 Cross-section of the capsule. 723. Vertical section of a seed and itj ea.br^ o. 



