154 PROCEEDINGS OF THE AMERICAN ACADEMY 



§ 1. Alata, Benth. Achenium trialatum. Embryo rectus seu rec- 

 tiusculus, axilis. Flos basi haud productus, nempe perigoniura 

 6-partiturn basi lata ipsa cum pedicello articulatum. — Perennes 

 seu biennes, caulibus scapiformibus 1 - 3-pedalibus, involucris 

 ssepissime longius pedunculatis laxe cymoso-paniculatis, foliis radi- 

 calibus spatbulatis seu lanceolati-% pube laxa. 



* Flores pi. m. pubescentes, nempe perigonio extus adpresse pilosulo, 

 filamentis basi et ovario superne parceque birsutis. Panicula 

 floribunda. Achenium supra medium trialatum. 



1. E. hieracifolium, Benth. in DC. 1. c. Planta Wrightiana, cine- 

 reo-pubescens ; foliis radicalibus subtus subtomentosis supra costaque 

 subtus laxe sericeo-villosis ; floribus flavis. — Guadalupe Mountains, E. 

 of El Paso, Texas, Wright. 



Var. /3. hemipterum. E. hemipterum, Torr. in herbariis. E. hiera- 

 cifolium, Torr. Bot. Mex. Bound, p. 175, pro parte. Humilius ; caule 

 tenuiore magis foliato ; pube tantum villosa parca; floribus ut videtur 

 roseis. — Hillsides of the Rio Grande, Parry. The foliage of this is 

 so different in pubescence from the type of the species (being just as 

 in the next) that with other specimens it may prove to be a distinct 

 species ; but the flowers are the same except (apparently) in color. 



* * Flores glaberrimi. Achenium a fere basi ad apicem alatum. 



2. E. alatum, Torr. (Sitgreaves, Rep. t. 8), Benth. 1. c. Elatum, 

 floribundum ; pube laxa hirsuto-villosa nunc parca vel aitate decidua ; 

 panicula decomposita; involucre 5-dentato; floribus parvis flavescen- 

 tibus ; alis fructus latiusculis tenuibus. — From the Platte to W. Texas 

 and New Mexico, by various collectors. — Var. glabriusculum, Torr. 

 Bot. Whippl. (on the upper Canadian, Bigelow), the most glabrate 

 form, has only a few scattered hairs on the leaves, and the involucres 

 are wholly glabrous. 



3. E. atrorubens, Engelm. PI. Wish p. 24. Foliis radicalibus vil- 

 loso-pubescentibus basi in petiolum longe alatum attenuatis; scapo 

 aphyllo ? glabrato inferne pi. m. fistuloso-inflato in cymam laxam dicho- 

 tomo-divisis ; involucris paucis longe pedunculatis brevi-campanulatis 

 5-7-dentatis ; perigonio rubente ; alis fructus angustis incrassatis. — 

 Cosihuiriachi, Mexico (Chihuahua), Wislizenus. 



§ 2. Eriantha, Benth. excl. sp. Achenium exalatum, ut in omnibus 

 subsequentibus. Embryo rectus, axilis, radicula cotyledonibus latis 

 breviore. Flos extus villosus vel sericeus, basi subito quasi in 



