GENUS 16. 



SPURGE FAMILY. 



5. Tithymalus arkansanus (Engelm. & Gray) 

 Kl. & Garcke. Arkansas Spurge. Fig. 2757. 



Euphorbia dictyosperma Engelm. in Torr. Bot. Mex. 



Bound. Surv. 191. 1859. Not F. & M. 1835. 

 Euphorbia arkansana Engelm. & Gray, Bost. Journ. Nat. 



Hist. 5 : 53. 1845. 

 Tithymalus arkansanus Kl. & Garcke, Abh. Akad. Berlin 



1859 : 66. 



Annual, olive green. Stem slender, 8'-2o' tall, with 

 few spreading branches above, topped by umbels 

 with 3 copiously dichotomous rays I'-ii' long; stem- 

 leaves cuneate or spatulate, 4'-ii' long, rather acute, 

 serrulate above the middle; bracts ovate to triangu- 

 lar-ovate, i'-i' long, truncate or subcordate at the 

 base, mucronate at the apex ; involucres about i" 

 high, with transversely elliptic glands less than i" 

 wide, the lobes usually ciliate; capsules ii"-ii" wide, 

 warty; seeds ovoid, closely reticulated, brown. 



Dry soil, Missouri to Colorado, Louisiana and Mexico. 

 May-Aug. 



6. Tithymalus Helioscopia (L.) Hill. Sun or Wart Spurge. 



Fig. 2758. 



Wartweed. 



Euphorbia Helioscopia L. Sp. PI. 459. 1753- 

 Tithymalus Helioscopia Hill, Hort. Kew. 172/3. 1768. 



Annual, glabrous or nearly so. Stem stout, 

 erect or assurgent, 8'-i2' tall, often branched 

 from the base, topped like the branches by a more 

 or less compound 3~5-rayed umbel ; leaves, except 

 the whorl at the base of the umbel, scattered, 

 spatulate, obovate, oblong, or sometimes nearly 

 orbicular, %.'-$' long, obtuse or retuse, serrulate, 

 narrowed to a short petiole ; bracts oblong or 

 ovate, serrulate, inequilateral, sessile ; involucres 

 oblong-campanulate, IT" long, nearly sessile, 

 usually with 4 oblong stalked unappendaged 

 glands ; capsule globose-ovoid, or somewhat de- 

 pressed, 2" in diameter, smooth, the lobes round- 

 ed; seeds ovoid, nearly ij" long, reddish brown, 

 strongly reticulate. 



In waste places, Newfoundland to Quebec, Ontario, 

 New York and Ohio. Also in Oregon. Naturalized 

 from Europe. Sun-weed. Turnsole. Little-good. Cat's- 

 milk. Wolf's-milk. Churnstaff. Wart-grass. Mouse- 

 milk. Wartwort. Mad-woman's-milk. Devil's-milk. 

 Seven sisters. June-Oct. 



7. Tithymalus Esula (L.) Hill. Leafy 

 Spurge. Faitour's Grass. Fig. 2759. 



Euphorbia Esula L. Sp. PI. 461. 1753. 

 Tithymalus Esula Hill, Hort. Kew. 174/4. 1768. 



Perennial by a horizontal rootstock, glabrous. 

 Stems often clustered, slender, mostly erect, 8'-2 

 tall, scaly below, branched above, topped by a 

 many-rayed umbel ; leaves few, all scattered, ex- 

 cept the whorl at the base of the umbel, linear or 

 oblong, 7"-2o" long, 2"-6" broad, entire, sessile; 

 those subtending the umbel lanceolate or oblan- 

 ceolate; bracts subreniform, mucronate; invo- 

 lucres campanulate, \\"-\\" long, nearly sessile, 

 bearing 4 unappendaged crescent-shaped glands; 

 capsule nodding, smooth; seeds oblong, terete, 

 smooth. 



In waste places, Maine to Ontario, New York, New 

 Jersey and Michigan. Tithymal. Naturalized from 

 Europe. Summer. 



