Criscianthus zambiensis (R.M.King & H.Rob.) M.A.Grossi & J.N.Nakaj., 2013

Grossi, Mariana A., Katinas, Liliana & Nakajima, Jimi N., 2013, Criscianthus, a new genus of Eupatorieae (Asteraceae) with a key to members of the tribe in Africa, Phytotaxa 141 (1), pp. 25-39 : 34-35

Criscianthus zambiensis (R.M.King & H.Rob.) M.A.Grossi & J.N.Nakaj. , comb. nov.

Basionym: Stomatanthes zambiensis King & Robinson (1975: 465) . Type:— ZAMBIA. Northern Province: Mporokoso District , Mporokoso-Kawimbe , close to Mporokoso , 7 January 1960, Richards 12084 (holotype K!, isotypes M!). ( Fig. 4 ) .

Subshrubs 0.30–1 m tall, with xylopodium. Stems pale yellow. Upper leaves close to the inflorescence alternate or opposite, rarely verticillate, lower leaves verticillate, in whorls of three, blade 3–7 × 0.5–2.1 cm, margins entire at the base and serrate to laciniate-lobate at the median and upper parts, glabrous or scarcely pubescent, with simple filiform hairs, upper face with sparce hairs, lower face more pubescent, surface punctate. Heads pedunculate, peduncles 5–25 mm, pubescent, with glandular and non-glandular hairs. Involucre 4.5–10 × 8–10 mm; phyllaries 7–10, subimbricate, trinerved, scarious at the margins, glabrous or pubescent, with scarce non-glandular, marginal hairs, rarely with glandular hairs, outer phyllaries 1.5–3 × 0.5–0.7 mm, intermediate 4–6 × 1–1.5 mm, inner phyllaries 4–8 × 1–1.5 mm. Florets with corollas 4.5–6 mm long, tube 2.5–4 × 0.3–0.5 mm, limb 1.5–2 × 0.6–1.5 mm, lobes 0.5–0.7 × 0.4–0.6 mm, thickened at the margins. Anthers 0.8–0.9 mm long, anther collar 0.4–0.5 × 0.1–0.2 mm, cells with transversely banded thickenings, anther appendages 0.2–0.54 × 0.2 mm. Style base surrounded by a nectariferous disc, shaft 7–8 mm long, style branches 2–2.5 mm long. Cypselae 2–3.5 × 0.7–1 mm, with abundant glandular hairs, and few 3-(6)-celled twin hairs, carpopodium 0.25 mm × 0.3 mm, with oblong cells. Pappus 5–6 mm long, of ca. 40 scabrous bristles unequal in length. Pollen grains P x E = (18 × 20) µm.

Etymology:—The specific epithet “ zambiensis ” refers to Zambia, which is part of the geographical distribution of the species, and to the African country where the type specimen was found.

Phenology:—Flowering from January to April. Fruiting capitula are found from May to August.

Distribution and ecology:— Criscianthus zambiensis grows in northern Zambia, adjacent areas of Malawi ( Fig. 4F ) and probably in Tanzania because of the close proximity of this country, at altitudes of 1200–2200 m. These areas correspond to the biogeographic province of Miombo woodland/savanna ( Udvardy 1975) and to the central Zambezian miombo woodlands ecoregion ( White 1983), characterized by the Miombo trees ( Brachystegia , Julbernardia , Isoberlinia , of the Fabaceae family). Criscianthus zambiensis grows in the wet miombo woodlands that receive more than 1000 mm of rainfall per year. Canopy height is usually greater than 15 m reflecting deeper and moister soils, which create favorable conditions for very rich vegetation ( Abdallah & Monela 2007). This species may be found in mixed woodlands and among grasses on loam soils, rock slabs, amongst boulders of rocky outcrops, and top of escarpments, sometimes associated with species of Helichrysum , Osteospermum (Asteraceae) , Eragrostis (Poaceae) , and Xerophyta (Velloziaceae) . The xylopodium of Crisciantus zambiensis , as in many typical pyrophytic savanna herbs and shrubs, prevents a complete damage of the plant during the dry season wildfires by remaining low to the ground.

Conservation:—Proposed here as endangered (EN) according to the IUCN (2010) criteria and subcriteria B2 ab (iii), i.e. the area of occupancy is estimated to be less than 500 km, severely fragmented, and there is a continuing decline in the extent and/or quality of the habitat.

Additional specimens examined:— ZAMBIA. Northern Province: Mbala (previously Abercorn) District , Kambole , near Kambole falls , 30 January 1964, H. Richards 18908 (K, US) ; Kambole escarpment, 19 February 1957, H. Richards 8251 (K); path to Katenga Falls, Kambole , 21 February 1957, H. Richards 8303 (K); Nyika National Park , 0.5 km SE of Zambian Govt. Rest House, 15 April 1986, D. Philcox et al. 9962 (K) . MALAWI. Northern Province : Rumphi District, Nyika, 30 March 1970, J. Pawek 3437 (K); Nyika National Park, Vitinthiza peak, 29 July 2009, S. Mphamba 950 (K); Mafinga Hill Top , Chitipa, 5 August 2007, H. Chapama et al. 705 (K) .

reference literature. Generic names are in boldface.

Figures

FIGURE 4. Criscianthus zambiensis. A. Apex of flowering branch. B. Capitulum. C. Floret. D. Cypsela and pappus. E. Fruit hair. F. Geographical distribution. A, from Richards 12084 (K); B–E, from Richards 18908 (US).