GENUS 16. 



SPURGE FAMILY. 



475 



ii. Tithymalus Peplus (L.) Hill. Petty Spurge. 

 Fig. 2763. 



Muphorbia Peplus L. Sp. PI. 456. 1753. 

 Xithymalus Peplus Hill, Hort. Kew. 172/3. 1768. 



jjw^nnual, glabrous. Stem rather slender, erect or nearly 



IJBO, 4'-i2' high, simple or branched, topped by a 3-5- 



flrayed umbel ; stem-leaves scattered, oblong or obovate, 



'i'-li' long, obtuse or retuse, entire, crisped, narrowed 

 into a slender petiole; those at the base of the umbel 

 whorled ; bracts opposite, ovate or triangular-ovate, 

 apiculate, sessile; involucres campanulate, almost ses- 

 sile, less than i" long, bearing 4 crescent-shaped unap- 

 pendaged glands prolonged into slender horns; capsule 

 globose-ovoid, i"-ii" in diameter, slightly nodding, 

 smooth, the lobes 2-keeled ; seeds oblong or oblong- 

 ovoid, whitish, nearly terete, marked with 1-4 series 

 of pits. 



In waste places, New Brunswick to western New York, 

 Wisconsin, Iowa, New Jersey, Pennsylvania and West Vir- 

 ginia. Bermuda, Jamaica. Adventive from Europe. Devil's- 

 milk. Seven sisters. Wartweed. June-Sept. 



12. Tithymalus commutatus (Engelm.) Kl. & Garcke. Tinted Spurge. 



Fig. 2764. 



Euphorbia commutata Engelm. in A. Gray, Man. Ed. 2, 



389. 1856. 

 Tithymalus commutatus Kl. & Garcke, Abh. Akad. Ber. 



1859: 82. 

 Euphorbia ohiotica Steud. & Hochst. ; Boiss. in DC. 



Prodr. 15: Part 2, 142. 1862. 



Biennial, yellowish green, often tinged with red, 

 glabrous. Stem slender, usually decumbent at the 

 base, 4'-: 5' long, branched, topped by a 3-rayed 

 umbel ; branches forked or umbellately branched ; 

 leaves, except the whorl at the base of the umbel, 

 scattered, spatulate to ovate, \'-\\' long, obtuse or 

 mucronulate, entire, flat, narrowed into a slender 

 petiole; bracts opposite, ovate-reniform ; involucres 

 campanulate, ii" long, sessile, bearing 3 or 4 crescent- 

 shaped unappendaged glands prolonged into slender 

 horns; capsule globose-ovoid, \\" in diameter, gla- 

 brous, the lobes rounded; seeds oblong, terete, 

 irregularly pitted. 



On hillsides, chiefly along streams, Ontario to Minne- 

 sota, Pennsylvania, Florida and Missouri. March-July. 



Tithymalus falcatus (L.) Kl. & Garcke, a native of 

 Europe, with spatulate leaves, subulate-tipped bracts and 

 rugose-pitted seeds, has been found in western Virginia. 



13. Tithymalus robustus (Engelm.) Small. 

 Rocky Mountain Spurge. Fig. 2765. 



Euphorbia montana $ robusta Engelm. Bot. Mex. Bound. 



Surv. 192. 1859. 

 E. robusta Small, in Britt. & Brown, 111. Fl. 2: 381. 



1897. 



Perennial by a perpendicular rootstock, glabrous, 

 glaucous. Stems slender, clustered, erect or assur- 

 gent,4'-i4' tall, slightly angled, scaly below, branched, 

 topped by a 3~5-rayed umbel ; leaves, except the 

 whorl subtending the umbel, scattered, ovate or 

 oblong-ovate, 5 "-8" long, thick, obtuse or apiculate, 

 entire, _ sessile; bracts opposite, triangular-ovate or 

 subreniform, involucres campanulate, \\" long, ses- 

 sile, bearing 4 somewhat crescent-shaped unappend- 

 aged buff crenulate glands ; capsule globose-ovoid, 

 2" long, horizontal, its lobes rounded; seeds oblong 

 or obovoid-oblong, terete, \\" long, gray, minutely 

 pitted. 



Hills and plains, South Dakota to Montana, Wyoming, 

 Nebraska, Arkansas and Arizona. May-Oct. 



