OF ARTS AND SCIENCES: NOVEMBER 11, 1863. 193 



Saskatchawan to Texas. A. pachycarpus, known only from a single 

 specimen, seems to be only a depauperate state of A. caryocarpus. 



2. A. Mexicanus, a. DC, PI. Hort. Genev. 5, p. 7, t. 3. A. 

 trichocaJyx, Nutt. in Torr. & Gray, Fl. 1, p. 332. Viridior, altior, 

 minus pubescens ; floribus albis vel ochroleucis apice purpureo seu 

 violaceo pi. m. tinctis ; calyce pube molli brevi albo-villoso vel tomen- 

 toso ; legumine ovato-globoso vix apiculato. — Plains from the Missis- 

 sippi River at St. Louis to S. Texas and to the base of the Rocky 

 Mountains. — As this has not yet been found even on the Mexican side 

 of the Rio Grande, the older name of Mexicaniis should perhaps give 

 way to Nut tail's good name of trichocalyx. Some of the Texan forms 

 especially, with less hairy calyx, run much too close to the foregoing 

 species ; but, on the whole, this pale-flowered and coarser fleshy- 

 fruited Astragalus seems to hold distinct. 



* * Ovarium cano-hirsutum : legumen vetustate nunc glabratum. 



3. A. Plattensis, Nutt. in Torr. & Gray, 1. c. A. caryocarpus^ 

 Torr. in Ann. Lye. N. Y. Laxe villosum ; stipulis majusculis ; floribus 

 ochroleucis nunc apice purpureo tinctis ; legumine ovato acuminato. — 

 Nebraska to Texas. 



Var. Tennesseensis. A. Tennesseensis, Gray in Chapm. S. Floi'a. 

 A. Plattensis, Gray, Man. addend. 1863, p. 9L Legumen oblongum, 

 subcurvatum. — Prairies of Illinois, and Nashville, Tennessee, to 

 N. W. Alabama. 



§ 2. Diphysi. Legumen ovatura vel globosum, membranaceum, ved- 

 cario-inflatum, fere glabrum, estipitatum, suturis utrisque introflexis 

 pi. m. didymum complete bilocellatum ; septo versus medium 

 seminifero ; loculis polyspermis. — Multicaules e radice perenni, 

 pube brevi vel subnulla ; stipulis discretis petiolo subadnatis. 

 Flores parvuli, albi vel cyanei, spicati vel subcapitati. 



* Humiles, glabri vel glabelli ; racemis capituliformibus densifloris. 

 Legumen vesicario-ovatum, acuminatum. 



4. A. DiPHYSus, Gray, PI. Fendl. p. 34. Subglaber ; foliolis 

 9 -11-jugis confertis carnosulis oblongis ; calycis tubo cylindraceo den- 

 tibus subulatis duplo longiori ; legumine glabei'rimo acumine incurvo. — 

 New Mexico, and probably in Utah. Flowers blue or purple, occa- 

 sionally white. Legume half an inch or more in diameter, grooved 

 down both sides. 



VOL. VI. 19 



