216 



Euphorbia petaloidea Engel m. Door ons gevonden 

 Augs. 1922 adventief te Amsterdam. De determinatie is 

 van Thellung, die er bij schreef, geen vergelijkings- 

 materiaal te hebben. De plant stemt echter zoo goed met 

 de diagnose overeen, dat wij niet aarzelen, de plant als 

 zoodanig te benoemen. Een diagnose vindt men in Britton 

 and Brown: An illustrated flora of the Northern United 

 States enz. Uit de determinatietabel halen wij de volgende 

 kenmerken : 



Glands of the involucre with petal-like appendages. 

 Leaves opposite, somewhat inequilateral, their base 

 more or less oblique. 



Leaves" entire; seeds smooth. 



Plants with an erect or ascending stem, branched 

 above, the branches ascending. 



Seeds nearly terete, V long, leaves usually 



flat and straight E* petaloidea» 



Seeds 4-an5led, ^// long, leaves often involute 



and curved E* Nuttallii» 



Euphorbia petaloidea Engelm. Bot. Mex. Bound. 



Surv. 185, 1859. Annual pale green, glabrow. Stem usually 



rather stout, erect, branched above, 6' — 2^ high; leaves 



opposite, linear, oblong or linear-lanceolate, 5''— 1' long, 



obtuse, usually flat, straight, entire, slender-petioled ; stipules 



a fringe of setae ; involucres solitary in the axils, oblong- 



campanulate, V long, hearing 4 wineglass-shaped glands 



about as long as the lobes, each subtended by a white 



ovate or orbicular entire or undulate appendage ; peduncles 



as long as the involucre ; capsule globose-reniform, T' long, 



seeds oblong-ovoid, nearly V long, ash-colored, minutely 



pitted, nearly terete. 



lowa to Wyoming and Texas. July^ — Sept. 

 De plant heeft een zoo geheel ander uiterlijk dan de 

 Europeesche Euphorbia's, dat niemand, aan wien we het 

 ex. toonden, er een Euphorbia in herkende. 



