Cuatrecasanthus
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Ordo: Asterales
Familia: Asteraceae
Name
Cuatrecasanthus H. Rob., Revista Acad. Colomb. Ci. Exact. 17(65): 209 (1989). – Wikispecies link – Pensoft Profile
Type species:
Vernonia sandemanii H. Rob. & B. Kahn (=Cuatrecasanthus sandemanii(H. Rob. & B. Kahn)H. Rob.)
Description
Erect branching shrubs, scrambling shrubs or trees (rarely vines) to 3.5 m tall; stems terete, striate, minutely pilose (pilosulous) with evanescent simple hairs or thinly tomentose; pith solid. Leaves alternate, petiolate; blades elliptical or lanceolate, base narrowly cuneate to attenuate, subchartaceous, margins entire to remotely subserrulate, narrowly recurved, apex usually sharply acuminate, adaxial surfaces pilosulous with simple non-septate, thick-walled trichomes, with numerous glandular dots, abaxial surfaces covered with thin whitish tomentum of prostrate myceliiform minutely branching trichomes; secondary veins 4–9 on each side of midvein, ascending basally at 45–60° angles. Inflorescence terminal on leafy stems, rounded corymbiform, branching alternate, with large foliaceous bracts only at lower primary nodes. Heads clustered and sessile in glomerules at ends of short branchlets (Figs 7C, 9B), individual heads cylindrical; involucral bracts ca. 15 in 5–6 gradate series (Figs 7D, 9C), inner bracts easily deciduous, outer bracts persistent; receptacle glabrous. Florets one per head; corollas lavender, outside minutely gland-dotted, distally sometimes pilosulous, basal tube narrow, ca. 2.5–4.0 mm long, throat lacking, lobes 5, linear, separated to base of limb, with somewhat thickened margins, not or scarcely distorted on drying (Figs 7E, 9D); anther thecae purple, with short papillose-fimbriate basal appendage, apical appendage ovate-oblong, ca. 0.5 mm long, glabrous; style base with stopper-shaped node, with thick-walled cells, sweeping hairs non-septate, obtuse to short-acute. Achenes prismatic, 10-costate (Figs 7G, 9F), surface sometimes fleshy, with numerous glandular dots, with few or no eglandular trichomes, with minute short-oblong raphids, base with broad annuliform carpopodium; pappus straw-colored, of 45–65 crowded rather persistent capillary bristles, about as long as corolla, barbellate, mostly some somewhat broadened and flattened distally, a few outer shorter bristles rather indistinct. Pollen ca. 40–45 µm in diam., spinulose, sublophate, tricolporate, with continuous perforated tectum between colpi.
In addition to the diagnostic generic characteristics are features of special interest such as the marginal teeth of the leaves that are incurved and appressed against the abaxial surface in all but one species (Cuatrecasanthus lanceolatus; Fig. 1A–B) and the finely branching myceliiform hairs on the abaxial surface of the leaves in all the species (Fig. 1C). In addition, there is variation on the leaf surfaces. The surfaces of the leaves have veins that can be exsculpate (above the surface), insculpate (below the surface), or even with the adaxial leaf surface (Figs 2–4). All but one of the species have veins on the adaxial surface that are even with the surface or slightly insculpate; one species has veins that are deeply insculpate (Cuatrecasanthus giannasii) and all six species have veins that are exculpate on the abaxial surface. The style branches are reported on one herbarium label as pale pink almost white; there are no additional data on the color of the styles. The genus occurs in Ecuador and Peru. The six known species can be distinguished using the following key:
Taxon Treatment
- Robinson, H; Funk, V; 2012: Cuatrecasanthus (Vernonieae, Compositae): A revision of a north-central Andean genus PhytoKeys, 14: 23-41. doi
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