SPURGE FAMILY 423 



1. M. annua L. Herb Mercury. Glabrous annual 6 to 15 inches high; nodes 

 on lower part of stems swollen; leaf -blades ovate to oblong, serrate, 1 to 2 inches 

 long; petioles 2 to 7 lines long; staminate clusters in interrupted spikes, the spikes 

 borne on peduncles 1 to 1^/2 inches long; pistillate flowers 2 or 3 in the axils, shortly 

 pediceled; lobes of the fruit with a shallow longitudinal channel on the back, the 

 dorsal areas softly spinose. 



European weed, locally naturalized : San Mateo Co. Mar. 



Locs. — Montara Mt., valley near, V. Duran; Pedro Valley, Abrams Sr Wiggins 180. 



Eef. — Mercubialis annua L. Sp. PI. 1035 (1753), type European. 



12. EUPHORBIA L. Spurge 



Herbs or shrubs. Involucres solitary in the forks or disposed in terminal cymes, 

 with 4 or 5 teeth or lobes alternating with glands borne in the sinuses; glands either 

 naked or appendaged (that is, with a colored margin) . Flowers monoecious, both 

 pistillate and staminate naked and included in an involucre which itself resembles 

 a flower but really encloses a cluster of flowers consisting of several staminate and 

 1 pistillate flower. Staminate flower very much reduced, consisting of a single 

 stamen; filament jointed on a short pedicel like it, the pedicel often with a minute 

 scale or bract at base, showing that the stamen is a distinct flower. Pistillate flower 

 supported on a pedicel in the center of the involucre and soon protruded from it, 

 consisting of a 3-celled ovary and 3 bifid stjdes. Capsule with 3 cells, each 1-seeded. 

 — Species over 600, all continents, chiefly warm temperate and subtropical, absent 

 from the arctic. (Euphorbus, King Juba's physician.) 



Bibliog. — Greene, E. L., Some species of Euphorbia, section Anisophyllum (Bull. Cal. Acad. 

 2:56-58, — 1886). Millspaugh, C. F., Euphorbiaceous plants * * * of Lower California (Proc. 

 Cal. Acad. ser. 2, 2:217-230,— 1889) ; Euphorbia serpyllifolia and its forms (Pitt. 2:82-86, pi. 1, 

 —1890); New or noteworthy species [of Euphorbia] (I.e. 2:87-90,-1890); Notes on the Eu- 

 phorbias of Dr. Edward Palmer's Durango (Mexico) collection of 1896 (Bot. Gaz. 25:13-25, — 

 1898) ; Notes and new species of the genus Euphorbia (Bot. Gaz. 26:265-270,-1898) ; [Chamae- 

 syce and other genera] (Field Mus. Publ. Bot. 2:401-420,-1916). Norton, J. B. S., A revision 

 of Am. species of Euphorbia of the section Tithymalus occurring north of Mexico (Rep. Mo. Bot. 

 Gard. 11:85-144, pis. 11-52,-1899). 



A. Stem leaves opposite, obuque at base (not oblique in no. 5) ; glands 2 to 4, usually 



WITH A PETAL-LIKE "WHITE OR REDDISH APPENDAGE (OR THIS SOMETIMES LACKING 



IN Nos. 8, 9 AND 11). — Subgenus Chamaesyce. 

 1. Leaf -blades serrate or serrulate ; stipules distinct ; annuals. 



Plants erect or nearly so ; herbage glabrous or slightly hairy ; stipules triangular, entire or slightly 



lacerate; capsule obtusely angled 1. -B. nutans. 



Plants usually prostrate. 



Herbage glabrous; stem and leaves mostly green or greenish, infrequently reddish; seeds 



quadrate-oblong or -ovate, smooth or irregularly rugulose 2. E. serpyllifolia. 



Herbage hairy or puberulent ; leaves often reddish or red-spotted. 



Capsules sparsely long-villous to glabrate; pubescence of young stems sparse, long-silky; 



leaves reddish or green, but not spotted 3. E. hirtula. 



Capsules pubescent, the hairs coarse, more or less appressed ; pubescence of young stems 

 coarse, spreading; leaves often with a central red spot i.E. maculata. 



. , S. Leaf-blades entire. 



Annuals. 



Leaf -blades linear ; herbage glabrous 5. E. parryi. 



Leaf -blades broader, roundish, ovate or obovate to oblong. 



Herbage pubescent ; leaf -blades round-ovate to oblong ; seeds oblong, acutely 4-angled ; 



Colorado Desert. 



Seeds slightly rugose transversely ; herbage glandular -pubescent 6. E. setiloba. 



Seeds with 4 deep transverse grooves; herbage cinereous-pubescent 



7. E. pediculifera. 



Herbage commonly glabrous ; leaf -blades deltoid-ovate or oblong-ovate to elliptic ; seeds 



usually more or less round-ovate. 



Seeds broadly cylindric-ovate ; glands entire, usually vrithout appendages 



8. E. ocellata. 



