Dalea ayavacensis var. ayavacensis

  • Title

    Dalea ayavacensis var. ayavacensis

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Dalea ayavacensis Kunth var. ayavacensis

  • Description

    78a.  Dalea ayavacensis Humboldt, Bonpland & Kunth var. ayavacensis

    (Plate LXXX)

    Foliage green or becoming so, the young leaves often silvery both sides, the adult primary ones (sometimes all) glabrate or glabrous above; spikes (2) 3-8 cm long, including bracts 13.5-22 mm diam; calyx-tube either glabrous or more rarely thinly pilose, the plumose teeth up to 4-5.5 mm long. — Collections: 5 (o).

    Habitat unknown, but to be expected on dry brushy hillsides or canyon terraces at ± 2250-2800 m, known from two remotely separate areas in the Andes of s. Ecuador and Peru: extreme n. Peru and adjoining Ecuador, on or near the Pacific slope; and on upper Rio Apurimac in Cuzco and adjoining Apurimac, Peru. — Flowering May to August, perhaps later. —Material: ECUADOR. Loxa: Loxa, Hartweg 727 (F, NY, OXF); Seemann 754 (K). PERU. Piura. Ayabaca: Ayabaca, typus. Apurimac. Aban- cay: Tranacapala, Univ. Cuzco 1264 (F). Cuzco. Anta: Cuzco to Abancay, Rauh- Hirsh P 1680 (NY).

    Dalea ayavacensis (of Ayabaca) H. B. K., Nov. Gen. & Sp. (Folio) 6: 486. 1823.— "Crescit prope Ayavacam Peruvianorum inter Loxam et Guancabambam, alt. 1407 hex..."—Holotypus, Humboldt & Bonpland 3483, P (herb. H. B. K.)!—Parosela ayavacensis (H. B. K.) Macbr., Field Mus., Bot. 4: 86. 1925.

    The apparent bicentric dispersal of var. ayavacensis is unexplained, but there seems to be no difference between the plants collected by Hartweg in Ecuador and the two cited from upper Apurimac valley. Because other known forms of D. ayavacensis sens. lat. are concentrated in northern Peru and adjoining Ecuador it is possible that the southern populations are adventive. In the early stages of my study, before the close kinship of D. ayavacensis and D. killippi had been appreciated, I interpreted the former as a variety of D. coerulea, of which it has nearly the foliage and flower, thinking that the characteristic linear calyx-glands might have arisen independently in the two areas from sympatric strains of D. coerulea var. longispicata. This, however, would not account for the long-tailed bracts common to var. ayavacensis and var. killippi, but not known in D. coerulea.

    Macbride (1927, p. 102, 111) at first distinguished Parosela ayavacensis from P. astragalina (= our D. coerulea) by a supposedly thicker flower-spike, but his concept excluded (as he already suspected) the genuine D. ayavacensis of Humboldt, being the equivalent of our D. coerulea longispicata. Subsequently (1943), finding the broad spike no longer significant, Macbride reduced all these names to the synonymy of D. coerulea. It thus happened that D. ayavacensis was lost sight of, and its peculiar calyx overlooked.