Inulanthera leucoclada (DC.)

Magoswana, S. L., Boatwright, J. S., Manning, J. C. & Magee, A. R., 2016, A taxonomic revision of Inulanthera (Asteraceae: Anthemideae) *, South African Journal of Botany 105, pp. 141-157 : 149-150

4. Inulanthera leucoclada (DC.) KällersjÖ in Nord. J. Bot. 5 (6): 539 (1986).

Hymenolepis leucoclada DC., Prodr. 6: 85 (1838). Athanasia leucoclada (DC.) Harv. in Fl. cap. 3: 19 (1865); Oliv. in Hooker's Icon Pl. 23: t. 2233 (1892); Hilliard, Compositae in Natal: 338 (1977).

Type: South Africa, [Eastern Cape], between Umsikaba and Umzimvubu rivers, 16 May 1832, Drège 5039 (G-DC, holo. – image!; K – image!, P – image!, iso.)

Single-stemmed, reseeding shrub 0.30–1.5 m, stems simple or sparsely branched in upper half, branches 2–4 mm diam., densely whitish woolly, sometimes glabrescent. Leaves sub-erect to spreading, ovate to lanceolate, 5–40 × 5–10 mm, base cuneate, margins sharply serrate, glabrous, coriaceous; axillary shoots absent. Capitula in dense compound corymbs 25–40 mm across, branches 10–35 mm long, inflorescence bracts lanceolate, 5–10 × 2–5 mm. Involucre subglobose, 8–10 × 7–12 mm, puberulous or glabrous; outer bracts ovate, 2–5 × 1–2 mm, acuminate, margins serrulate. Receptacle paleate. Florets 60 to 70. Pappus formed by cypsela ribs extended apically into horns 0.2–0.3 mm long, sometimes broadly membranous or scale-like and ± connate basally. Cypselas obconic, 1–2 × 0.5–1.0 mm, prominently 8- to 10-ribbed, glabrous to slightly scabrid. Fig. 8 .

Diagnostic characters

Inulanthera leucoclada is a distinctive species with virgate, densely whitish woolly stems ( Fig. 8A ) and ovate, closely serrate leaves without axillary leaf tufts. The relatively large heads, 7–10 mm long, contain 60 to 70 florets each.The pappus is formed by either horn-like extensions of the ribs or membranous scales. Inulanthera leucoclada is unique in the genus in its single-stemmed habit and reseeding fire survival strategy (resprouting in the other species of Inulanthera ). These two fire survival strategies are common in fire-prone vegetation, particularly fynbos ( Cowling, 1987; Schutte et al., 1995; Manning and Goldblatt, 2005). Herbarium field notes on several collections of I. leucoclada noted it as being locally frequent but we were unable to relocate the species in several localities amongst older vegetation, presumably because the species is a relatively short-lived member of early successional stages after fire.

Distribution, ecology and phenology

This species ranges from Kokstad in the Eastern Cape through southern and central KwaZulu-Natal, in moist grassland and on forest margins at altitudes 350 m to above 1800 m ( Fig. 9 ). Flowering is from January to May. The species is a short-lived element of earlier post-fire successional communities, and annual fires are likely to be detrimental to its survival.

Additional specimens examined

South Africa.KWA‐ ZULU NATAL: 2830 (Dundee): Hlolelo, ‘The Cave’ (− DB), L ' Ange 37 (NU). 2929 (Underberg): Richmond, Hella-Hella (− DB), Gibson s.n. (NU); Hella-Hella road, S-facing slopes above Umkomaas (− DB), Hilliard and Burtt 10324 (NU); Royal Natal National Park, MontAux- Sources (− DB), Trauseld 50 (NU); Royal Natal National Park, Tugela Gorge pathway, Tendeli (− DB), Hilliard and Burtt 15391 (NU), Schrire 1695 (NH), Hilliard 2849 (NU), Stewart 2044 (NU); Tugela valley, Mont Aux- Sources, Natal (− DD), Sim 19015 (BOL, NU, PRE). 3030 (Port Shepstone): Friedenau, Umgai Flats (Alexandra Bay) (− BC), Rudatis 164 (NBG); Umtamvuma Nature Reserve (− CC), Hilliard and Burtt 10241 (MO, NU), Hilliard 6762 (NU), Abbott 1944, Strey 9869 (NH); above Umtamvuma River (− CD), Nicholson 1018 (PRE). EASTERN CAPE: 3028 (Matatiele): Farm Bernina, about 30 km (direct) NW from MacClear, Eland's Height (− CC), Bester 652 (NH). 3029 (Kokstad): Zuurberg mountains near Kokstad (− BC), Tyson 1185 (BOL, PRE, SAM); Zuurberg (− BC), Hilliard and Burtt 10209 (MO, NU); Mount Malowe, near Clydesdale (− BD), Tyson 1059 (BOL, SAM), Tyson 2057 (BOL); S-facing slopes on bank above stream, just below waterfall, 0.7 km of Sugar Bush and 0.5 km N of National (Durban-Umtata) road (− CC), Steiner 1448 (NBG); Mount Insizwa (− CD), Hilliard and Burtt 6556 (MO, NBG, NU), Magoswana 15 (NBG); Weza, Zuurberg (− DA), Hilliard and Burtt 6556, Hilliard and Burtt 8081 (NU); Harding, Bangani Forest, Ngele Nature Reserve (− DA), Abbott 6980 (NH); Ngeli slopes (− DB), Hilliard 1771 (NU). 3128 (Umtata): Mtentu River Gorge (− CD), Edwards 3246 (NU). 3129 (Port St. Johns): ± 10 km to Umkhambati Nature Reserve on road from Holy Cross (− BD), Magoswana 16 (NBG); Kambati waterfall (− DB), Strey 8673 (NU, PRE).

Figures

Fig. 8. Inulanthera leucoclada, Rudalis 164 (NBG).A.Flowering branch.B.Leaf.C.Leaf tissue plan (Magee 1098, (NBG)).D.Involucral bracts.E.Palae.F.Floret.G.Cypsela.H.Cypsela.I.Style. J. Anthers.Arrow indicates leaf midrib. Scales: A and B:10 mm; C–I: 1 mm. Artist:S.L. Magoswana.

Fig.9. Known distribution of Inulanthera leucoclada (circles),I.montana (stars) and I.nuda (triangles).