CONTRIBUTIONS TO WESTERN BOTANY NO. 16 



of the plants is that of E. albomarginata, but without the white mar- 

 gined leaves, but that plant is never rooting at the nodes. The species 

 is Tropical and is common probably as far north as Phoenix, and at 

 least as far west as Sells, and eastward to Texas and southward. 

 Wooton and Standley evidently followed Coulter too closely in making 

 their keys. Coulter's keys are poor. I don't see how a plant could 

 root at the nodes and be annual. The original description says it is 

 an annual. 



Euphorbia setiloba Eng. No. 24855. Quartzite, Arizona. September 17, 

 1929. This prostrate annual of the stictospora group, has exactly the 

 habit of stic- folia, and grows with the latter. Whole 



plant glandular-hairy throughout even to the pods when young, but 

 there are no evident glands on the hairs, but they are evidently viscid 

 and entangle grains of sand and stand out at right angles to the stem. 

 Leaves thin, flat, wholly entire, obliquely ovate to oval, rarely 5 mm. 

 long, opposite, several times shorter than the internodes. Stipules 

 apparently absent or not distinguishable from the hairs. Pods stngose 

 when young, mostly ciliate on the margins when old, about 1 mm. 

 ''.nu and with rounded angles. Seeds 2/3 mm. long, ovate to ovate- 

 oblong, whitish, sharply angled and angles not indented., then the 

 faces concave and grooved with not over 6 sulci, and sometimes a 

 little meshed. Appeendages conspicuous and white and lacerate into 

 ubulate h irs -1 t gl nda conspkttous and black-purple. This differs 

 from E. stictospora and hirtula in the entire leaves and conspicuously 

 Leerate apped ages Stictospora has the long pubescence but is 

 without appendages, and the leaves are serrate above. Hirtula has 

 very much shorter pubescence, and has crenate and very narrow- 

 appendages, and obtuse angled and ovate seeds, and serrate leaves. I 

 do not see any good reason for recognizing the segregates of Euphor- 

 bia as genera.' The species of this group are too much involved to be 

 good species. 



F'uphorbia vermiformis N. Sp. No. 24S56. Ajo, Arizona. September 18, 

 1929. Along a dry wash. Peren: form stems 2-3 



feet long, and spreading or prostrate with alternate branches and very 

 long internodes, and almost obsolete stipules. Whole plant ashy to 

 the glabrous appendages which are obovate and 1-2 mm. long and 

 white or pink and verv conspicuous, the plant reminding one of E. 

 corollata in that respect. Final branches an inch or two long and 

 with about .3 pairs of leaves which are about an inch long, broadly 

 linear to narrowly oblong, obtuse at both ends but not oblique, invo- 

 lute, entire Pods with rounded angles, appressed-ashy with very 

 short hairs 2 mm. long, single. Seeds about 1 mm. long, a little 

 oblique, oblong, rounded and obscurely if at all angled but with the 4 

 ribs verv low and with 4 conspicuous and raised rings, like pediculi- 

 fera, obtuse. The seeds would put this at once in the pediculifera 

 group, and not in petaloidea. which the plant resembles much At first 

 ->V o-,. v.w.ild tiiinl ih-f thi< \v;t< E. rr.olula, but the leaves are 



