Dalea galbina


Rupert C. Barneby

97.  Dalea galbina (Macbride) Macbride

(Plate LXXXIII)

Awkwardly open-branching, sparsely leafy shrubs up to 1-1.5 mm tall, appearing glabrous to the silky-barbate spikes but the young twigs, the leaf-rachis, and the stipules internally pilosulous with fine ascending hairs up to 0.4-0.5 mm long, the low- tuberculate stems at first castaneous but the old bark becoming gray and furrowed, the foliage green, the small, thick-textured leaflets smooth above, densely punctate beneath; leaf-spurs 0.5-1 mm long; stipules triangular-subulate castaneous, dorsally glabrous; intrapetiolular glands 2 immersed; post-petiolular glands small but prominent; leaves shortly petioled, the main cauline ones 7-14 mm long, with thick-margined punctate rachis and 2-3 pairs of narrowly obovate but tightly folded (thus apparently oblanceolate) emarginate, mostly backward-arched leaflets 2-3 mm long, the terminal leaflet sessile, the leaves of numerous knoblike spurs axillary to drought-deciduous primary ones similar but smaller with only 1-2 pairs of tiny leaflets; peduncles terminal to leafy branchlets of the year, 1-1.5 cm long; spikes moderately dense, narrowly ovoid-acuminate becoming cylindroid, without petals 10-11 mm diam, the densely pilosulous axis 2-5 cm long; bracts deciduous, 2.5-3.5 mm long, the broadly oblong-elliptic, navicular body 2-3 mm long, in profile 1.1-1.3 mm wide, narrowly membranous-margined, heavily gland-tuberculate and (especially at base and distally) thinly pilosulous, glabrous within, abruptly contracted into a subulate cusp up to 0.5-0.7 mm long; calyx 4.4-4.6 mm long, densely pilose with straight spreading-ascending hairs up to 1.2-1.5 mm long, the tube 2.4-2.5 mm long, recessed behind banner and the orifice oblique, with 10 primary and also 10 intercalary ribs, these slender but prominulous, castaneous or livid, the 20 intervals charged each with 1 row of 3-5 orange glands, the triangular, gland-spurred teeth somewhat unequal, the dorsal one 2-2.1 mm long (± 0.4 mm shorter than tube); petals pale greenish-yellow, not fading brown, the banner heavily gland-sprinkled in the greenish eye and like the keel gland-tipped, the epistemonous ones perched low on androecium (1.4-1.9 mm above hypanthium); banner ± 6.7 mm long, the claw 3.2 mm, the suborbicular-flabellate blade 3.7-4 mm long, 4 mm wide, the basal lobes folded inward and adherent to form lateral pockets, the comet at base shallow; wings 6 mm long, the claw 2 mm, the lance-ovate blade 4.3 mm long, 1.9 mm wide; keel 7.7 mm long, the claw 2.4 mm, the elliptic blades 5.7 mm long, 2.4 mm wide; androecium 10-merous, 7.5 mm long, the longest filaments free for 2.7-3 mm, the connective gland-tipped, the yellowish anthers 0.7 mm long; pod not known. — Collection: 1 (typus).

Rocky outcrops, ± 2330 m (7000 ft), known only from the type-locality on upper Rio Huallaga, e. slope of Peruvian Andes in lat. ± 10° S. — Flowering late April and May.

Dalea galbina (Macbr.) Macbr., Candollea 7: 222. 1937, based on Parosela galbina (greenish-yellow) Macbr., Field Mus., Bot. 4: 104. 1927.— "PERU: southwestern rock- outcrops, Huanuco, April 26, 1923, Macbride 3500..." Holotypus, F! = NY Neg. 8603\ isotypus, US!

A singular dalea, the only member of the genus with 20-ribbed calyx, and the only Peruvian species, other than D. cylindrica, with yellow petals. The yellow-flowered forms of D. cylindrica, all confined to the Pacific slope of the Andes, are easily distinguished by their more ample, thin-textured leaflets and persistent interfloral bracts.

References: [Article] Barneby, Rupert C. 1977. Daleae Imagines, an illustrated revision of Errazurizia Philippi, Psorothamnus Rydberg, Marine Liebmann, and Dalea Lucanus emen. Barneby, including all species of Leguminosae tribe Amorpheae Borissova ever referred to Dalea. Mem. New York Bot. Gard. 27: 1-892.

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