372 



EUPHORBIACEAE. 



[VOL. II. 



4. Euphorbia Geyeri Engelm. & Gray. 

 Geyer's Spurge. (Fig. 2310.) 



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

 Hist. 5: 260. 1847. 



Annual, olive-green, glabrous. Stem branched 

 from the base, the prostrate branches radiately 

 spreading, wiry, 2 / -i5 / long; leaves oblong or ovate, 

 2 // -6 // long, obtuse, usually mucronulate, entire or 

 nearly so, oblique, obtuse or subcordate at the base, 

 short -petioled; stipules a fringe of short setae; in- 

 volucres usually solitary in the axils, campanulate, 

 about Yt" high, with 4 wineglass-shaped glands 

 shorter than the lobes, each subtended by an in- 

 conspicuous white or red entire or lobed appendage; 

 peduncles as long as the involucres, or longer; cap- 

 sule globose-renifonn, about ^'long, nodding; seeds 

 narrowly ovoid, 3^ " long, ash -colored, nearly terete. 



In sandy soil, Minnesota to Illinois and Kansas. 

 July-Sept. 



5. Euphorbia serpens H.B.K. Round- leaved Spreading Spurge. 



(Fig. 2311.) 



I'.uphorbia serpens H.B.K. Nov. Gen. 2: 52. 1817. 



Annual, pale green, glabrous, sometimes glau- 

 cescent. Stem branched from the base, the 

 slender or filiform branches prostrate, a'-iz' long; 

 leaves orbicular, orbicular-ovate or oval, \"-$" 

 long, obtuse or eniarginate, entire, often slightly 

 revolute-margined, short-petioled, the base ob- 

 lique, rounded or subcordate; stipules triangular, 

 somewhat incised at the apex; peduncles slightly 

 longer than the petioles; involucres solitary in 

 the axils, nearly W high, bearing 4 sessile saucer- 

 shaped glands shorter than the lobes, each sub- 

 tended by a minute irregular crenulate append- 

 age; capsule nodding, depressed-globose, i" in 

 diameter; seeds oblong-ovoid, W long, smooth, 

 obtusely 4-angled, light gray. 



Illinois to Iowa and Kansas, south to Mexico. 

 March-Oct. 



6. Euphorbia serpyllifdlia Pers. 

 Thyme-leaved Spurge. (Fig. 2312.) 



Euphorbia serpyllifolia Pers. Syn. 2: 14. 1807. 



Annual, dark green, or becoming reddish, gla- 

 brous. Stem branched from the base, the slender 

 branches prostrate or ascending, 4 / -i2 / long; 

 leaves oblong to spatulate, i%"-6" long, obtuse 

 or retuse, nearly entire, or serrulate to below the 

 middle, short-petioled, the base oblique, mostly 

 truncate or obtuse; stipules at length a fringe of 

 weak setae; involucres solitary in the axils, some- 

 times clustered toward the ends of the branchlets, 

 less than i" long, bearing 4 disk-like glands each 

 subtended by a narrow lobed appendage; capsule 

 i" broad, slightly nodding; seeds ovoid, hardly 

 W long, 4-angled, the faces transversely wrink- 

 led and pitted. 



In dry soil, Wisconsin to California, south to 

 Mexico. May-Sept. 



