268 DICOTYLEDONS. 



oval clusters borne on slender, long peduncles which arise from the axils of 

 the leaves. Petals are wanting, and the calyx is usually five-parted, with 

 the margin colored. The stamens are mostly eight, and the styles three on 

 the compound ovary. There is a single seed developed in the ovary which 

 in ripening forms a three-angled achene like a buckwheat grain. The 

 species of dock, and of field, or sheep, sorrel (rumex) also belong to this 

 family. 



CURVEMBRYy€. 



517. The purslane family (portulacacese). — The little spring beauty (Clay, 

 tonia virginica), shown in fig. 349, is a member of this family. It occurs 

 in moist places. The stem arises from a deeply buried tuber, and bears, 

 about midway, two long, narrow, fleshy, thick leaves. The upper part of 

 the stem bears a raceme of pretty rose-colored flowers. The sepals are two. 

 The petals are five in number, and the stamens of the same number are 

 inserted on little claws at the base of the petals. The ovary has a long 

 style, three-cleft at the apex, and in fruit it forms a three-valved pod. The 

 ovule in claytonia and other members of the family is curved, and conse- 

 quently the embryo is curved. 



518. In some other related families, like the goosefoot family, the embryo 



Fig. 3S°- 

 Curved embryos of Russian thistle (Salsola soda). (Warming.) 



is also curved. In fig. 350 is shown the embryo of the Russian thistle 

 (Salsola kali), a member of this family. 



POLYCARPICE. 



519. Lesson VII. The crowfoot family (ranunculaceae). — 



The marsh-marigold (Caltha palustris) is a member of this family. 

 The leaves are heart-shaped or kidney-shaped, and the edge is 

 crenate. The bright golden -yellow flowers have a single whorl 

 of petal-like envelopes, and according to custom in such cases 

 they are called sepals. The number is not definite, varying from 



