Ethulia L.f.

Robinson, Harold, Skvarla, John J. & Funk, Vicki A., 2016, Vernonieae (Asteraceae) of southern Africa: A generic disposition of the species and a study of their pollen, PhytoKeys 60, pp. 49-126 : 66-68

Ethulia L.f. Figures 7 C–E ; 8 D–F

Ethulia L.f. Dec. Prima Pl. Rar. Horti Upsal. 1 (1762); L.f. ex L., Sp. Pl. ed. II: 1171 (1763). - Type: Ethulia conyzoides L.f.

Hoehnelia Schweinf. in Höhnel, Zum Rudolf-See und Stephanie-See 86 (1892). - Type: Hoehnelia vernonioides Schweinf. in Höhnel.

Resources.

Treatment of the genus by Gilbert and Jeffrey (1988).

Descriptions.

Annual or short-lived perennial herbs, rarely rhizomatous; stems terete and usually striate, with broad solid pith; hairs uniseriate with erect apical cells, with glandular dots. Leaves alternate, sessile or short petiolate; blades thinly herbaceous, ovate to linear lanceolate, base cuneate or continuous onto stem, margins subentire to serrate or dentate, apex acute to obtuse, surfaces glabrous to densely pubescent; venation pinnate with ascending secondary veins. Inflorescence terminal, corymbiform to rather cymiform, lower bracteoles a reduced foliiform, peduncular bracteoles filiform. Heads rather small, with broadly campanulate involucres; involucral bracts 15-40 in 2-3 usually subequal series; receptacle flat or slightly convex, epaleaceous. Florets 3-100 in a head, strongly exserted; corollas white or pink to purple, with glandular dots on surface, with a narrow cylindrical base, limb narrowly funnelform to narrowly campanulate; lobes lanceolate, without apical hairs; bases of anther thecae rounded, not tailed; apical appendages glabrous; style base without node; branches with sweeping hairs shortly acute. Achenes cylindrical with 2-6 usually paler ribs, sides with glandular dots, rarely with short white setulae; raphids short-oblong; pappus lacking or a coroniform rim. Chromosome number n = 10, 20 ( Pilz 1980; Gilbert and Jeffrey 1988).

Pollen: ca. 35 μm in diam. in fluid; tricolporate, sublophate, echinate, spines long; tectum continuous in intercolpi and at poles, distinctly microperforate; columellae below spines firmly attached to footlayer (Fig. 8 D–F ).

Notable secondary metabolites: 5-alkylcoumarins ( Bohlmann and Jakupovic 1990, as Ethulia conyzoides ).

Figures

Figure 7. Photographs of Erlangea and Ethulia: A-B Erlangea misera S. Moore, and C-E Ethulia conyzoides L. f. subsp. conyzoides, note: Ethulia has no capillary pappus. See Appendix C for citation details.

Figure 8. Scanning electron micrographs of acetolyzed echinolophate pollen of Erlangea and sublophate pollen of Ethulia. A-C Erlangea misera (Oliv. & Hiern) S. Moore. A Poral view B Near polar view C Grain fragment. D-F Ethulia conzyoides L. f. D Equatorial view, showing comparatively blunt spines E Lateral view F Grain fragment. (D-F Funk 12708 G Petelot 4047 H Lewis 6025; Ethulia views from Robinson and Skvarla (2010 )).