(Plate CXXX)

Slender annuals, 0.8-2 dm tall, the solitary erect simple 1-3-cephalous stem glabrous and purplish toward base, then straminous and thinly pilosulous with fine weak spreading hairs up to 0.4-1 mm long, the foliage sparse and early deciduous, the sub- persistent leaf-stalks pilosulous, the membranous, flat or loosely folded leaflets green and glabrous above, either glabrous or thinly pilosulous beneath, or ciliolate, minutely gland-sprinkled dorsally; leaf-spurs 0.4-0.7 mm long; stipules linear-caudate, stramineous, thinly pilosulous 1.5-5 mm long; intrapetiolular glands 2, small; post- petiolular glands prominent, small, blunt; leaves 1.5-3.5 cm long, with narrowly margined rachis and (2) 3-5 pairs of oblanceolate to oblong-obovate, deeply retuse or obtuse leaflets 4-8.5 (9) mm long, the terminal one stalked; peduncle 3-30 mm long; spike moderately dense, ovoid becoming oblong, ± 0.7 mm diam, the pilosulous axis (4) 8-20 mm long; bracts persistent, 3-4 mm long, the oblong-obovate navicular body loosely clasping base of calyx, 2-2.4 mm long, in profile 0.6-0.9 mm wide, broadly hyaline-margined, along the back above middle herbaceous, livid, sparsely gland-pustulate and pilosulous, abruptly contracted into a subulate tail 1.4-1.7 mm long; calyx 3.3-4.1 mm long, pilosulous with ascending spiral hairs up to 0.6-0.9 mm long, the tube 1.8-2.1 mm long, somewhat recessed dorsally, the ribs slender but prominulous, the flat hyaline intervals charged with 1 row of 3 (4) small golden glands, the triangular-aristate teeth unequal, the dorsal one 1.4-2 mm long, the lateral and ventral pairs successively a little shorter, all entire and plumulose to apex; petals pale purplish or whitish, glabrous and glandless, the wings very small or perhaps sometimes lacking, the keel perched near or above middle of androecium, ± 2 mm above hypanthium; banner 3.4-3.5 mm long, the filiform claw 1.9-2.3 mm, the deltate- cordate, minutely emarginate blade open at base, 1.2-1.6 mm long; wings ± 1.8 mm long, the claw 0.9 mm, the obliquely oblanceolate blade 0.9 mm long, 0.4 mm wide; keel 2.4-2.6 mm long, the claws 0.7-1.2 mm, the obliquely ovate blades 1.5-1.8 mm long, 0.9 mm wide; androecium 7-androus, 3.4 mm long, the central stamen and two on each side fertile, two interposed barren and shorter, the longer filaments free for 0.7 mm, the connective gland-tipped, the anthers 0.2 mm long; pod 2-2.5 mm long, in profile almost isotriangular, each side slightly convex, the style-base at comer, the prow filiform, livid, the valves in upper 1/3 thinly papery, eglandular, barbulate with hairs up to 0.5-0.8 mm long, in lower 2/3 hyaline, glabrous; seed 1.5-1.7 mm long. — Collections: 2 (o).

Stony places, 1900-2000 m, known only from two localities on the Pacific slope of the Peruvian Andes in s. Ayacucho and Moquegua. — Ephemerophyte, flowering after rains . — Material: Ayacucho. Lucanas: between Nazca and Puquio, Ferreyra 5486 (US).

Dalea moquehuana (of Depto Moquegua) Macbr., Field Mus., Bot 13³: 370. 1943.-"Moquehua: Between Moquehua and Torata, rainy-green formation, 2000 meters, Weberbauer 7433..." — Holotypus, collected March 21, 1925, F! = NY Neg. 8602; isotypi, GH, WIS!

A preeminently singular little dalea, the only monocarpic one known to occur on the west slope of the Peruvian Andes and, with the exception of the Bolivian D. tapacariensis, the only autochthonous annual Dalea in South America. A simple, erect, subfiliform but wiry stem ending in one to three spikes of plumose calyces characterizes the very few specimens examined, but more vigorous individuals, branched from the base or distally, must be expected. The species seems beautifully adapted to the irregular and precarious rainfalls of its desert home, prepared to shed at first the leaflets and eventually the leafstalks of all cauline leaves before the pods reach full maturity. The degeneration of the extremely small, almost colorless corolla, involving the loss sometimes of wing-petals and (so far as known) always of some stamens, is of great interest because it runs parallel with that observed in several North American species of subgen. Dalea. The process has not gone so far, however, to obscure the relationship of D. moquehuana to the herbaceous but perennial D. exilis and kindred small-flowered species of the Amazon watershed, for the calyx and petals, although diminished in size, have remained in form little altered.