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190 UNITLD STATES AND MEXIuAN BOUNDARY. 



II. ZYGOPRYLLE^ 



791 



Nutt 



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Phil. Soc. {n. ser.) 5, p. 173. Rio Coleto, Texas; Thurher. ''Many years ago Mr. Nuttall / 



gave me specimens of this plant, named E. hexagona. Part of these were sent to Sprengel, J 



who first published a description of the species in the work quoted. Eight years afterwards 



Mr. N. described the plant under another name. It is remarkable for being polygamous ; most 



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of the involucres containing only male flowers/' — Torrey^ M8S. 



Euphorbia BiLOBATA (nov. spec): annua, erecta, gracilis; foliis oppositis breviter petiolatis lan- 

 ceolato-linearibus acutatis integris glabriusculis, rameis angustioribus ; anthodiis alaribus 

 campanulatis; glandulis bilobis, appendiculis binis lanceolatis seu abbreviatis ; stylis vix basi 

 connatis ad medium bilobis ; stigmatibus erectis subteretibus ; capsula laBviuscula, seminibus 

 ovatis acutis angulato-tuberculatis. Near the Copper Mines, New Mexico ; Bicjel w. Eastern 

 Sonora ; Wright^ (No. 1831.) Stems 6-15 inches high ; leaves 10-15 lines long, 1- 2 lines broad; 

 seeds 0.8 line long, strongly tuberculate and almost angular. Glands remarkable and very 



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constant in shape ; appendages white. Near E. hexagona; distinguished by the acuter more 

 uniform leaves, bilobed glands, terete stigmata and smaller tuberculate seeds. 



Euphorbia bifurcata (nov. spec.) : glabra ; caule erecto dichotomo ; foliis oppositis ovatis seu 



em 



stipulatis ; anthodiis alaribus breviter pedunculatis ; lobis 5 ovatis truncatis fimbriato-multifidis ; 

 glandula singula cyathiformi late albo-appendiculata, appendice transverso emarginato ; stylis 

 basi coalitis ad medium bifidis, stigmatibus filiformibus. Moist places, Valley of the Limpio, 

 July ; Bigeloto. Over a foot high ; leaves 1 inch long, \ inch wide ; petiole a little shorter 



than leaf. 



§ III. CYATHOPHOR^. 



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Euphorbia dentata, Michx. ; ^ rigidia : humilior rigida; foliis parvis coriaceis reticulato- 

 venosis scabris margine revolutis. Head of San Pedro river ; Wright. (No. 1837-) Near 

 Monterey, Mexico ; Dr, Edioards. y. cuphosperma : erecta, stricta, dentata seu parce pilosa ; 



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foliis lanceolatis seu lineari-lanceolatis elongatis subdentatis ; capsulis glabris seu pilosis ; semi- 

 nibus majoribus tuberculato-angulatis. Copper Mines, New Mexico; Wright^ (No. 1834,) to 

 Sonora ; ScJiott. Ojo de Gabilari, Chihuahua ; Thurher. 



Euphorbia heterophylla, Liym. (E. cyathophora, ilfwrr.) Yar, graminifolia : foliis angusto- 



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 T I" ^^ 



linearibus. Crevices of rocks and dry beds of rivers. Rio San Pedro, Texas ; Bigelow, Scliotty 

 Wright, (No, 653.) South of El Paso ; Wright, (No. 1835.) 

 Euphorbia barbellata^ (nov. spec.) : annua, erecta, glabriuscula ; foliis sparsis linearibus seu 



h 



lanceolato-linearibus seu ovatis lobatis(][ue breviter petiolatis parce argute dentatis, subtus ad 

 nervum medium parce pilosis, basi pilis longioribus confertis barbatis ; foliis floralibus ovatis 

 seu e basi dilatata elongatis, basi roseis ; anthodiis glomeratis majusculis ; glandula singula 

 eessili lobis inciso-dentatis breviore ; stylis brevibus erectis basi vix connatis ad medium bifidis. 

 On the Rio Grande, near Eagle Pass ; Wright. Rio Frio ; Bigelow. Near E. heterophylla, but 

 stouter, leaves very sharply serrate, involucre larger, styles shorter. Leaves 2-4 inches long, 



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Beard of coarse hair at base of leaves very conspicuous. 

 3C,) : erecta, glaberrima ; foliis breviter petiolatis span 



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