342 LEQUMINOSAE 



Dry flats or sag:ebrush slopes, 10,500 to 11,000 feet: White Mts. East to the 

 desert rangfes of Nevada. June. 



Locs. — Cottonwood Creek, Duran 1628; Campito Mt., Jcpsnn 7301. 



Refs. — Kentkophtta teoetaria Rydb. Bull. Terr. Club 34:421 (1907). Astragalus tege- 

 tarius Wats. Bot. King 76, pi. 13, figs. 7-10 (1871), type loc. East Humboldt Mts., Nov., Wat- 

 son 286. 



2. K. montana Xutt. Stems several from the branched root-crown, forming 

 a prostrate mat 3 to 15 inches wide; herbap:e g^rayish-strij^ose; leaves crowded, the 

 5 to 7 leaflets subulate, spine-tippod, 2 to 5 lines lonpr, divaricate in ajre; peduncles 

 hardly over 1 line long; cah'x-tecth subulate-setaceous, much longer than the cam- 

 panulate tube; corolla yellowish, 2 lines long; pods ovate, acuminate, sometimes 

 elliptic, 21/2 to 3 lines long. 



Rocky alpine summits, (9500 or) 11,000 to 13,000 feet: both sides of the 

 Owens Valley trough. East to New ]\Iexico and Nebraska, north to Saskatchewan. 

 June-Aug. 



Locs. — Mt. Dana, Chesnut 4" Dfew; Mt. Warren, Congdon; Wyman Creek, White Mts., 

 Duran 1741. 



Refs.— Kextrophyta Montana Nutt.; T. & G. Fl. 1:353 (1838), type loc. "hills of the 

 Platte", Nutiall; Jepson, Man. 562, fig. 552 (1925). Eomalobus montanus Britt. ; Britt. & Br. 

 111. FI. 2:306 (1S97). Astragalus montanus Jones, Rev. Astrag. 80 (1923) ; not A. montauus L. 

 (1753). Tragacantha montana Ktze. Rev. Gen. PI. 2:941 (1891). 



23. ASTRAGALUS L. Rattle-weed. Loco-weed 



Herbs with odd-pinnate leaves and persistent stipules. Flowers purple, pale 

 yellow or white, in spikes, racemes or heads. Racemes mostly spike-like, often 

 crowded. Calyx 5-toothed. Corolla usually long and narrow; keel mostly obtuse. 

 Stamens diadelphous (9 and 1). Pod turgid, or inflated and bladder-like, some- 

 times not inflated, 1-celled or partly or completely 2-celled by the intrusion of one 

 or both sutures, tardily dehiscent, 2 to many-seeded. Seeds small, usually reni- 

 form on slender funiculi. — Species about 950, common in all north temperate 

 regions, many in South America, a few in Africa, none in Australia. (Ancient 

 Greek name for some leguminous plant.) 



Note on the natural units and on endemism. — Astragalus is one of the major genera of seed 

 plants in California from the standpoint of number of species. Determination of the genetical 

 values of the species rests mainly on the shape and size of the pod, its inflation, compression or 

 obcompression, and degree of intrusion of the dorsal suture. The primitive condition of the pod 

 is 1-celled (as in A. oophorus). The partially or wholly 2-cclled condition is brought about by 

 the intrusion of the dorsal suture which thus forms an ingrowing partition-fold. In some species 

 the intrusion extends only part way to the opposite suture (A. mohavensis, A. rattanii), thus 

 making the pod incompletely 2-cclled, while in other species its extends to or even unites with the 

 opposite suture, making the pod more or less completely 2-celled (A. breweri, A. nevinii, A. lenti- 

 ginosus). This partition fold, when present, is usually quite constant in character. In some spe- 

 cies (as in A. bolanderi) it does not extend throughout the entire length of the fruit but is lacking 

 at the apical portion where the pod becomes narrow. When the mature pod dehisces the seeds, 

 in such species, thus find exit through the open spaces between the partition and lateral walls. 

 On account of the intrusion of the dorsal suture, grooved pods characterize certain species. In a 

 few species pods may also be grooved ventrally (A. kernensis). The presence or absence of a 

 stipe, the number of leaflets, the amount and more especially the character of the pubescence are 

 also points well used in weighing the species. By means of these characters the natural units are 

 rather readily defined and involve no such profound problem as is presented in the genera Lu- 

 pinus or Lotus or even Trifolium. In addition to their technical characters the species here pre- 

 sented are enforced as natural units by plant habit, the peculiarities of which in each species are 

 commonly distinctive and often singular or striking. 



Difficulties in the genus result largely from the publication of species on the basis of flower- 

 ing material, of immature fruiting specimens or of material so scanty as to invite mystery instead 

 of clarity. If studies were restricted to long series of specimens with the flowering and fruiting 

 stages fully coordinated our knowledge of Astragalus would soon present a happier and more 

 promising aspect. 



In California the genus is best developed in the deserts and bounding desert ranges. Only 

 a few species occur in the Great Valley and only one has any wide distribution on the west slope 



