STANDLEY TREES AND SHRUBS OF MEXICO. 597 



Leaves entire or toothed. 



Capsule large, 5 to 20-celled, elastically dehiscent; bracts large, 

 membranaceous, inclosing the buds, in anthesis irregularly 

 cleft 20. HURA. 



Capsule small, usually 3-celled, or the fruit drupaceous and many- 

 celled. 



Stamens numerous 21. MABEA. 



Stamens 1 to 3. 



Staminate calyx none or rudimentary. 



Inflorescence terminal 22. DALEMBERTIA. 



Inflorescence axillary 23. GYMNANTHES. 



Staminate calyx well developed. 

 Calyx 3 to 6-parted. 



Seeds carunculate ; inflorescence usually terminal. 



24. SEBASTIANIA. 

 Seeds ecarunculate ; inflorescence axillary. 



25. CORYTHEA. 

 Calyx shallowly lobate. 



Stamens united; fruit drupaceous 26. HIPPOMANE. 



Stamens distinct ; fruit capsular. 

 Column of the capsule present, the seeds usually persist- 

 ent upon it after dehiscence of the capsule. 



27. SAPIUM. 



Column none, but the receptacle usually persistent after 



the fall of the capsule cells, becoming indurate, 2 or 



3-horned 28. STILLINGIA. 



1. EUPHORBIA L. Sp. PI. 450. 1753. 

 Reference: Boissier in DC. Prodr. 15': 7-187. 1865. 



Shrubs or small trees vv^ith milky juice; leaves alternate, opposite, or verticil- 

 late, on long or short petioles, usually entire ; flowers involucrate, the involucre 

 cuplike, 4 or 5-lobed, with 4 or 5 glands within, the glands often with petal-like 

 appendages ; perianth none ; flowers unisexual ; stamen 1 in the staminate 

 flowers ; fruit a 3-lobed capsule. 



One of the largest genera of plants, represented in Mexico also by many 

 herbaceous species. The genus is divided by some authors into several, but the 

 present writer has preferred to consider the species as belonging to a single 

 genus. 



Euphorhia splendens Bojer, the " crown-of-thorn?.," a native of Madagascar, 

 is often cultivated in Mexico, where it is known as " corona de Cristo." It 

 has somewhat climbing stems which are covered with long stout spines; the 

 involucre is subtended by two large red bracts. 



A. Leaves alternate, only those of the inflorescence, if any, opposite. 

 Glands of the involucre without petal-like appendages. 



Leaves 1 cm. long or shorter 1. E. longecomuta. 



Leaves 2 to 15 cm. long or larger. 



Leaves and stems pubescent 2. E. fulva. 



Leaves and stems glabrous or nearly so. 

 Bracts brfght red ; leaves long-petiolate, broadest at or below the mid- 

 dle, often lobed 5. E. pulcherrima. 



Bracts green, white, or yellowish, rarely pink ; leaves sessile or short- 

 petiolate, broadest above the middle, entire. 

 Leaves 2 to 4 5 cm. long; floral bracts acute 6. E. xylopoda. 



