SPURGE FAMILY 147 



glands at its notches. Sterile flowers many, borne inside the 

 involucre at its base (Fig. 23, A), each- consisting only of a 

 single stamen attached by a joint to a pedicel which looks like 

 a filament. Fertile flower standing alone at the center of the 

 involucre (Fig. 23, C) (soon pushed out by the growth of its 

 pedicel), consisting only of a 3-lobed and 3^celled ovary, 3 2- 

 cleft styles, and 6 stigmas. Pod 3-celled and 3-seeded. 



A. Cultivated shrubs. 



1. E. splendens Bojer. Crown of Thorns. An extremely prickly 

 shrub, with many erect, few-leaved branches. Leaves obovate or 

 obovate-spatulate, mucronate, entire, each with two very sharp 

 prickles (longer than the petiole) as stipules. Peduncles long, 

 sticky, each bearing 2-4 objects which appear to be showy scarlet 

 flowers, but which are actually 2-bracted involucres containing the 

 true flowers. Involucral scales somewhat kidney-shaped, mucronate. 

 Flowering all the year round. Cultivated in greenhouses. From 

 Mauritius. 



B. Herbs with rather showy white flower clusters. 



2. E. marginata Pursh. Snow on the MouNXAiif. Annual. Stem 

 stout, 1-3 ft. high. Leaves sessile, ovate, obovate or oblong, acute, 

 |-3 in. long, the upper ones whorled and with white petal-like mar- 

 gins. Involucres 5-lobed in an umbel-like inflorescence with three 

 forking rays. In dry soil W. and commonly cultivated. 



3. E. coroUata L. Flowering Spurge. Perennial. Stem erect, 

 umbellately branched above, smooth or downy, 1-3 ft. high. Leaves 

 of the stem alternate, those of the branches usually opposite or 

 whorled, rather thick, oval to narrowly oblong, pale beneath, usu- 

 ally slightly downy. Flowering branches repeatedly forked; invo- 

 lucres terminal and in the forks of the branches, peduncled ; glands 

 4-.5, oblong, green; appendages white and petal-like, showy. Cap- 

 sule erect, seed smooth or faintly pitted. Common in dry, open 

 woods. 



C. Herbs: No. 4 i native species; No. 5 cultivated from Europe or 

 escaping from gardens. Flower clusters in umbels, not white. Involucre 

 Jfr or 5-lobed, each lobe with a gland. 



4. E. dictyosperma Fisch. & Mey. Annual. Stem slender, 8-18 in. 

 high, erect. Stem leaves oblong-spatulate to obovate, serrate ; floral 

 ones roundish-ovate, somewhat heart-shaped. Flower cluster a com- 

 pound Timbel, the rays once or twice 3-forked, then 2-forked. Seeds 

 covered with a network. Prairies and roadsides. 



