250 Engelmann and Gray, 



clivity of sandstone hills near Industry. May — June. Rays 

 yellow, turning white when fading. 



268 &. 269. Senecio ampullaceus, (Hook?) : annuus vel 

 biennis ; caule erecto fistuloso striato superne ramoso ; foliis 

 inferioribus obovato-spathulatis in petiolum decurrentibus, 

 superioribus ovato-lanceolatis acutis basi subcordata semiam- 

 plexicaulibus, omnibus subintegris vel denticulatis ; cyma co- 

 rymbosa ; pedicellis apice demum incrassatis ; involucro squa- 

 mis setaceis paucis calyculato ; radiis 7-9 ; acheniis strigoso- 

 canescentibus. 



Var. a glaberrimus (No. 268) : caule foliisque angusti- 

 oribus subintegerrimis glabris. Wet prairies. 



Var. (3 floccosus (No. 269) : caule foliisque junioribus 

 latioribus cano-floccosis ; superioribus e basi latiore acumina- 

 tis, nunc grosse repando-dentatis. — Sandy prairies in loose, 

 dry soil. April. Both forms are certainly annual or biennial. 



270. Lygodesmia aphylla, (3 Texana, Torr. fy Gr. Fl. 

 II. p. 4S5. Prairies. June — July. Roots penetrating deep 

 into the soil. Some of the radical leaves are runcinate-pinna- 

 tifid, with subulate lobes. 



271. Pyrrhopappus grandiflorus, Nutt. Prairies, near 

 San Felipe. April. Perennial ; the slender perpendicular 

 root enlarging, at the depth of a few inches, into an oblong 

 tuber, similar to the root of Cynthia Dandelion. Scapes 

 several from one root, with or without a bract in the middle. 



272. Asclepias (Otaria) Lindheimeri (n. sp.) : caudice 

 perpendiculari incrassata caulem herbaceum pubescentem 

 singulum erectum (vel plures adscendentes) emittente ; foliis 

 oppositis ovatis obtusis (aut rarius lanceolatis) basi nunc sub- 

 cordatis breviter petiolatis utrinque puberulis ; pedunculis 

 brevissimis lateralibus ; pedicellis gracilibus pubescentibus 

 corollae laciniis acutiusculis subduplo longioribus ; cucullis ad 

 apicem sensim dilatatis subtrilobatis ; processu bifurco, ramo 

 altero brevi incluso recto, altero longiore incurvo exserto ; 

 folliculis ovato-lanceolatis acuminatis puberulis carina exteriore 

 setulis mollibus pi. m. conspersis. — Black, clayey soil, near 



