Dalea galbina

Title

Dalea galbina

Authors

Rupert C. Barneby

Scientific Name

Dalea galbina (J.F.Macbr.) J.F.Macbr.

Description

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.