122b.  Dalea eriophylla Watson var. frankenioides Barneby

(Plate CX)

Leaflets linear-oblanceolate, very strongly involute, green and glabrous, in contrast to white-villosulous internodes of the stem; stipules and bracts castaneous and glabrous dorsally, densely pubescent within. — Collection: 1 (typus).

Hot arid hillside, 2250 m, associated with Yucca carnerosana, in w. foothills of Sierra de Catorce, mpo Catorce, San Luis Potosi. — In flower in October, perhaps also in spring.

Dalea eriophylla var. frankenioides (resembling Frankenia) Barneby, var. nov., a var. eriophylla foliolis glabris viridibus, stipulis bracteisque extus glabratis castaneis intus seri- ceo-canis, tuboque calycino extus glabro tantum ad orem ciliolato absimilis. — San Luis Potosi: ladera caliza con vegetacion de Yucca Carnerosana, 2250 m, 4 km al este de la Estacion Marona, mpo. de Catorce, oct. 6, 1956, Jerzy Rzedowski 8171. — Holotypus, ENCB; isotypus (fragm), NY.

Because this remarkable plant was found growing close to a population of typical D. eriophylla (Rzedowski 8167), it would seem likely to represent nothing more unusual than one of those marked pubescence variants that are by now familiar in Amorpheae, even though not understood. This case is more complex, however, the vesture being not simply lost, but lost in part and in part regained, suggesting a dislocation of some magnitude in the genes. The bracts and stipules of var. frankenioides are not simply glabrate versions of the typical phase, but have the pubescence reversed, being hairless dorsally and silvery-silky within. The contrast between the small, crowded, fleshy, yellowish-green leaves and the intervening white-tomentulose interodes is particularly striking.