1S4 



16 STKIGILOSI. 



Pods oliart:i('»i'U> to l»H[)ery. ]>Mi<li-iit. (jipp iriMuly Hf«ceii(ling 

 in A. Tolucaiiiis), pcirily lo fully '-icelUMl by iln- intrusion of the 

 dorsal suture us a 1 mil partition, raruly much kulc-itf dursally, 

 iiutlined lu be witlt^- }ibi>\e, linear t(» oval, stipuafe (almost sessile 

 in A. reptans ami (Jobrensis, and fully so in ]>Iatytropifi), inflated 

 (scarcely so in A. recurvus ami slraturensis), with cross-section 

 triquetrous to rouml, wiiii ventral suture the more arched or if it 

 is concave toward the end then the tip is declined (except in A. 

 Cobreiisis). Flowers about horizontal, small (large and 2 cm. 

 long in A. re})taMH), rarely 1 cm. long, white or whiti^^h (banner 

 rarely purple), with campauulate calyx and trianguhir teeth uiost- 

 ly about as long as tube. Peduncles slender, at least as long as 

 the leaves (sometimcH iihorter in A. Tolucanus). Leaves slender, 

 eiiort-petioied (long-petiolcd in A. platytropis), with rather 

 niany pairs of leaflets which are narrowly to broadly el!ij)tical 

 (sometimes linear in A. Brandegei), obtuse and luwstly thin, 

 nearly contiguous (except in A. recurvus and Brandegei). Stij)- 

 tiles connate below (free in A. ^traturensis and lirandeaei). 

 Sterna slender to filiform, decumbent to weakly erect (cr«^eping 

 and rooting in A. reptans), flexuous, with rather many intt rnod^'s 

 (almost none in A. platytropis). Tufted perennials {:\. Brande- 

 gei is a winter annual) of the Middle Temperate to ibe Tiopical 

 life zones (A. platytropis appears as if subalpine). This rather 

 loosely inter-related group is closely connected with the Atrnti 

 but lacks the very narrow rakish leaves and aborting h afl-'ts ai.d 

 rigid petioles, etc. The species are all southern (except A. i»Uty- 

 tropis), reaching only to central Utah, growing among jiinc for- 

 ests and junipers mostly and rarely in oak brush. A. platytrops 

 grows iii rich soil in coniferous open forests, and reptans eeems to 

 grow in rich and open warm meadows. 



KEY 



A. Pods linear, curved, papery, not inflated, not wider above, evident- 

 ly stipitate, aboui: 1.5 cm. long and 2-3 mm. hign, triquetrous in cross- 

 section, and sulcate dorsally. Flowers rather many, racemose, broad, 

 about 7 mm. long. Calyx tube about 2 mm. , acute at base, with teetii 

 nearly as long as tube. Peduncles in the upper axils and about 1 dm. 

 long and with floral rachis 1-2 dm. long in addition. Pedi^eli 1-2 mm. 

 long, and nearly equaled by the ovate bracts. Leaflets narrow. Stems 

 densely tufted and 1-3 ft. long, with rather many internodes 3-8 ^m. 

 ong. Recurvi, 



