Jeffreycia H. Rob., S.C. Keeley & Skvarla, 2014

Robinson, Harold, Keeley, Sterling C., Skvarla, John J. & Chan, Raymund, 2014, Two new genera, Hoffmannanthus and Jeffreycia, mostly from East Africa (Erlangeinae, Vernonieae, Asteraceae), PhytoKeys 39, pp. 49-64 : 58-60

Jeffreycia H. Rob., S.C. Keeley & Skvarla gen. nov.

Type.

Vernonia zanzibarensis Less.

Small to moderate-sized; branching, often scrambling shrubs; stems woody, with narrow solid pith; hairs simple, without cap-cells, sometimes forming loose tomentum. Leaves alternate; petioles distinct, short to elongate; blades ovate to elliptic or panduriform usually with basal auricles, abruptly delimited from petiole at the base, 2.5 to ca. 11 cm long, ca. 1.5-7.5 cm wide, margins crenate or serrate, apices acute to scarcely acuminate, rarely obtuse, upper surface sparsely pilosulous to hispidulous, lower surface sparsely pilosulous to tomentellous, with many glandular dots; secondary veins 4-6 on each side, with unusual somewhat meandering course, spreading at 45-60° angles. Inflorescences terminal, with branches alternate and usually ascending at 30° angles or less, usually with minute bracteoles, sometimes primary bracteoles larger and foliiform; heads crowded at ends of longer branches, with distinct short peduncles; involucral bracts persistent, subimbricate in ca. 4-5 series or with differentiated long, linear-lanceolate basal bracts, bracts, except at base, smooth outside, without median keel; receptacle scarcely convex, epaleate, epilose, with proturberant scars; florets 5-40 in a head; corollas purplish, 5-11 mm long, with some glandular dots outside, few or no hairs below tips, basal tube slender, half as long as the corolla, throat half as long as the limb, ca. as long as the lobes, lobes strictly narrowly lanceolate, with sides straight from base to apex, erect, not recurving, sometimes with stiff hairs at tip; anther thecae without glands, calcarate at base, with narrow tails; endothecial cells with out obvious nodes; apical appendages narrowly lanceolate; style with basal node; sweeping hairs with blunt tips, restricted to branches, often lacking for some distance above bases of branches. Achenes 2-4 mm long, with 4 or 5 poorly differentiated angles, with or without glands or setulae, with scattered idioblasts on surface sometimes in vertical series, inner cells of achene wall with distinct firm cell walls, containing small subquadrate raphids; carpopodium stopper-shaped or somewhat turbinate and asymmetrical, with many series of subquadrate, thick-walled cells; pappus white, with inner series capillary, often deciduous, 4.5-7.0 mm long, gradually narrowed to tips, somewhat flattened on outer surface; outer series of short persistent scales, minute to 0.5 mm long. Pollen ca. 40 µm in diam. in fluid, sublophate, tricolporate, with perforated tectum continuous between colpi.

Etymology.

The new genus, Jeffreycia , honors the author of the study of the Vernonieae of East Tropical Africa ( Jeffrey 1988) whose work has been one of the most helpful in resolving the tribe in Africa.

Number of species.

Five species are currently placed in the genus.

In addition to the species listed below, Jeffrey (1988) included another three species in his aggregate, Vernonia bruceae C. Jeffrey, Vernonia stuhlmanii O. Hoffm., and Vernonia fischeri O. Hoffm., but these have not been seen in this study and therefore are not included in the new genus. Of these, Vernonia fischeri O. Hoffm. (1895) and Vernonia stuhlmannii O. Hoffm. (1898) are described with leaf bases truncate to subcordate, and both species are probably members of Jeffreycia , distinguished from the others by the appendages on the tips of their involucral bracts. However, Vernonia brucaea is described with "foliis ellipticis vel lanceolatis basi late cuneatis vel rotundatis". Not stated is whether that leaf base is as abrupt at the insertion on the petiole as in all the species of Jeffreycia recognized here, and any close relationship to Jeffreycia is doubtful.

Notes on morphology.

Regarding the shape of the leaf base, while it is similar to cordate, Jeffrey (1988) refers to it as panduriform. The auricles result mostly from a constriction above the base of the leaf blade. This character is lacking only in those specimens of Vernonia zanzibarensis Less. that have longer petioles. Some specimens combine long hairs at the apices of the corolla lobes as in Vernonia zanzibarensis with panduriform bases on short-petiolate leaves, and it is apparently plants like these that have been interpreted by Jeffrey (1988) as hybrids between that species and Vernonia hildebrandtii Vatke. However, it is possible that such leaf blades are just a variant of Vernonia zanzibarensis that has reverted to or retained the leaf form that is characteristic of all the other members of the genus.