Dalea ayavacensis

  • Title

    Dalea ayavacensis

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea ayavacensis Kunth

  • Description

    78.  Dalea ayavacensis Humboldt, Bonpland & Kunth

    (Plate LXXX)

    Bushy when mature and up to 1.5 m tall or perhaps more, sometimes flowering precociously as a coarse, suffrutescent, monopodial herb ± 1 m tall, paniculately branching distally, the young stems and often the foliage densely silky-pilosulous with fine antrorsely ascending and spreading hairs up to 0.4-0.9 mm long, the foliage at first silvery-cinereous but becoming (or sometimes from the first) greenish-cinereous or green, the leaflets equally pubescent both sides or glabrescent to glabrous above, punctate beneath; leaf-spurs 1-2 mm long; stipules linear-subulate, stiff, densely pilosulous, 4.5-8.5 mm long; intrapetiolular glands 2, spiculiform; post-petiolular glands small, often concealed by vesture; leaves shortly petioled, the main cauline ones 3-7 cm long, with stiff, narrowly margined rachis and (4) 5-8 (9) pairs of oblong-elliptic to broadly oblong-oblanceolate, obtuse or subacute, gland-mucronulate, dorsally keeled leaflets 5-15 mm long; spikes mostly terminal to leafy branchlets, sessile or shortly pedunculate (peduncles up to 1.5-3 cm long), ovoid early becoming cylindric, densely many-flowered but not conelike, including bract-tails 12-22 mm diam, the densely pilosulous axis finally 3-12 cm long; bracts persistent, the ovate- oblong, navicular body 3-4 mm long, narrowly membranous-margined, either pubescent or glabrous dorsally, contracted into a tail 1-9 mm long; calyx 4.7-8 mm long, the glabrous, rarely thinly pilosulous, vernicose tube 2.2-2.8 mm long, subsymmetric at orifice, the slender but prominulous ribs brown or yellowish, the membranous intervals charged along either side, parallel with the ribs, with a linear, orange gland extending from near base to the sinuses, the triangular-aristate teeth a little unequal, the dorsal one (2.5) 3.9-5.5 mm long (0.3-3 mm longer than tube), all plumose- ciliate with spreading hairs up to ± 1-1.6 mm long, when long stellately spreading and flexuous in age; petals ± bicolored, the banner opening whitish with green eye- spot, rubescent, gland-tipped and -sprinkled, the epistemonous ones perched low on the androecium, (1) 1.1-2.8 mm above hypanthium, either pale blue or vivid cobalt blue, the keel gland-tipped; banner 5-7 mm long, the claw 2-3.4 mm, the broadly ovate-cordate, hooded blade open at base, either glabrous or obscurely puberulent dorsally above claw, 3.1-5 mm long, 3-5.6 mm wide; wings 4-6.3 mm long, the claw 1.4-2.6 mm, the blades 2.7-4 mm long, 1.3-1.9 mm wide; keel 5-8.8 mm long, the claws 1.9-3.4 mm, the ovate-elliptic blades 3.4-6 mm long, 1.7-3.2 mm wide; androecium 10-merous 5-10.5 mm long, the longer filaments free for 1.6-2.5 mm, the connective gland-tipped, the anthers 0.45-0.6 mm long; pod (scarcely known) apparently as in D. coerulea.

    My concept of this rare but evidently polymorphic species is so drawn as to include all those Peruvian and Ecuadorean daleas that resemble D. coerulea in habit and in the long-toothed calyx externally glabrous and lustrous or thinly pilose up to the plumose orifice, but differ in one characteristic feature of the calyx. In all forms of D. coerulea the glands of the intercostal calyx-membranes, of whatever size and however few or many they may be, are relatively small, elliptic or circular in outline, and situated in one vertical row occupying the middle of each panel. In D. ayavacensis the glands of each interval are two or sometimes three, elongately linear, at least the two lateral ones aligned vertically along each side of the panel adjacent to the ribs. With a calyx of this type there is correlated (with one exception) a long-caudate type of interfloral bract which imparts to the flower-spike a teasel-like aspect not seen in D. coerulea. The still scanty material of D. ayavacensis, as defined by the peculiar calyx, shows a dismaying variability in pubescence of the foliage and particularly in size of flower and length of androecium. This is the more difficult to interpret due to ignorance of its scope both within and between populations and lack of data on patterns of dispersal. The recognition of three varieties proposed herein is obviously provisional, but seems justified, even required, at the level of information attained.