EUPHORBIACEAE 125 



Glands of involucre without petal-like appendages. 



Stem-leavea opposite. 8. E. dentaia. 

 Stem-leaves alternate, not entire. 



Capsules smooth. 9. E. heterophylla. 



Capsules warty. 10. E. Arkansana. 



Stem-leaves alternate, entire. 11. E. Cyparisaias. 



1. B. Nuttallii (Engelm.) Small. Erect, 6'-20' high, glabrous: 

 leaves often involute and somewhat curved, truncate and mucronate at 

 apex : involucral glands bearing large white appendages : seeds 4-angled. 

 — Frequent in rooky barrens from Westport to Little Blue Tank and 

 southwestward. July-September. 



2. E. serpens H.B.K. Widely prostrate-spreading, glabrous : involu- 

 cral glands bearing small white crenulate appendages : seeds 4-angled.— 

 Common in rich soil. July-October. 



3. E. glyptosperma Engelm. Ascending or prostrate, glabrous : leaves 

 linear- oblong, falcate, finely serrulate : glands ot the involucre with small 

 white crenulate appendages : seeds 4-angled, sharply transversely wrin- 

 kled. — Often common on sand-bars along the Missouri Eiver. 



4. E. maculata L. Procumbent, puberulent or hairy : leaves ovate- 

 oblong to linear-oblong, often blotched with red : glands of the involucre 

 with small whitish appendages : seeds 4-angled, usually strongly trans- 

 versely wrinkled. — Abundant in waste places. May-October. All speci- 

 mens examined have the involucre more or less^left on one side. 



5. E. nutans Lag. Erect, l°-2° high, smooth : leaves ovate-oblong, 

 somewhat falcate, serrate : involucres in dense clusters : glands of the in- 

 volucre bearing orbicular entire appendages : seeds black, four-angled and 

 ridged. — Abundant in waste places. June-October. 



6. E. corollata L. l°-3° high, erect, smooth : leaves oblong, often 

 emarginate at apex, nearly sessile : glands of the involucre bearing 5 con- 

 spicuous white petal-like appendages : seeds sparingly pitted. — Common 

 in barrens and prairies throughout the southern part. June-September. 



7. E. margiuata Pursh. l°-4° high, erect, hairy : leaves oval, sessile, 

 mucronate : glands of involucre white-appendaged : seeds reticulated and 

 tuberculate. — Occasionally adventized in waste places, especially at Dod- 

 son and Independence. July-September. 



8. E. dentata Michx. G'-a" high, erect, somewhat hairy : leaves 

 Qvate-lanceolate, coarsely toothed, petioled : involucral glands not ap- 

 pendaged : seeds tuberculate. — Common in open grounds. June-October. 

 A form commonly adventized at Sheffield has the upper leaves linear- 

 lanceolate and entire. 



9. E. heterophylla L. 6'-2° high, erect, nearly glabrous : leaves 

 linear to oblong-orbicular, sinuate-toothed, serrate or entire, often red- 

 blotched, the upper often fiddle-shaped : involucral glands not appehd- 

 aged : seeds tubercled. — Common in rocky isoil throughout, especially in 

 the southern part. 



