Achyranthemum sordescens (DC.) N.G.Bergh, 2019

Bergh, N. G. & Manning, J. C., 2019, Achyranthemum N. G. Bergh, a new genus segregated from Syncarpha DC. (Asteraceae, Gnaphalieae) *, South African Journal of Botany 125, pp. 434-456 : 451-453

4.6. Achyranthemum sordescens (DC.) N.G.Bergh , comb. nov.

Helichrysum sordescens DC., Prodr. 6: 178 (1838). Syncarpha sordescens (DC.) B.Nord. in Comp. Newsl. 17: 6 (1989).

Type: South Africa, Eastern Cape, ‘ Alghoa [Algoa] Bay’, 1835, Drège 2166 (G-DC G00470515 , holo.–digital image!)

Low, sprawling, often clump-forming shrublet much-branched from the base, in exposed positions about 150 mm high, to about 700 mm in more sheltered habitats, stems woody at base, with a loose, woolly, grey-green indumentum, shoots terminated by synflorescences but new shoots initiated from below the synflorescence and frequently overtopping the capitula, stems below synflorescences densely leafy. Leaves imbricate, appressed then apically erect-spreading or recurved, linear-oblanceolate, weakly to strongly conduplicate, 10–25 × 2.0–4.0 mm, soft-textured, pungent, apical mucro ± 1.2 mm long, both surfaces densely villous, with very long fine white hairs forming a thick, diffuse tangled indumentum that completely obscures the leaf surface. Capitula terminal in corymbs of (2–)3 to 4(–8), lateral capitula overtopping the central one, narrowly cupulate, 7.0–10.0 × 4.0–10.0 mm; lateral peduncles 15–25 mm long, terminal peduncles 2–6 mm long, densely woolly with a loose layer of long interwoven white hairs; involucral bracts ±60, in ±6 series, erect, lanceolate, acute-apiculate, with a distinct midvein, cream-coloured becoming brownish or grey, stereome thickened, lamina thin especially apically, outermost bracts lanceolate, 4–5 × 1.0– 1.2 mm, middle larger, 7 × 2 mm, innermost linear with obtuse, apiculate apex, 4.2–5 × 0.5–0.8 mm. Florets ±(20–)30–60, corolla tubular for most of its length, 0.4 mm diam., abruptly expanded apically to double this diameter, yellow becoming brown after anthesis, 6.5–7.0 mm long × 0.4 mm diameter (expanded to 0.8 mm apically), lobes recurved after anthesis, triangular, acute with marginal vascular trace, abaxially glabrous; anther apex caudiculate. Cypselae ovoid, 1.2–1.3 × 0.6 mm, pale brown. Pappus bristles united at the extreme base, shaft densely barbellate, apices nude, slender, acute. Flowering time: (October–) November–March ( Fig. 8 ).

Distribution and ecology: Restricted to consolidated coastal sand habitats in the area around Port Elizabeth in the Eastern Cape, from the Maitland River mouth just west of Port Elizabeth to Kenton-on-Sea in the east.

Diagnosis: Achyranthemum sordescens has been confused with both A. argenteum and A. recurvatum on account of their similar greytomentose, recurved foliage, but it differs from both in its more woolly A. sordescens indumentum of very long, fine, tangled hairs and smaller, cream (fading to grey or brownish) capitula 7–10 × 4–10 mm in size and housing no more than 60 florets. Achryanthemum argenteum has a fine indumentum of short straight hairs, bright white involucral bracts that remain so on drying, larger capitula (12–18 × 10–18 mm) and at least 80 but frequently over 100 florets per capitulum. Like A. recurvatum , A. sordescens can have strongly recurved leaves, but the leaves are soft rather than rigid, and the indumentum is looser, more tangled and made up of finer hairs. The capitula of both A. recurvatum and A. af fi ne are white tinged pink, not cream becoming brownish as in A. sordescens , and in A. recurvatum the capitula are solitary, while in A. sordescens they are borne in corymbs of 2 or up to 8.

Conservation status: This species is listed as Vulnerable (Raimondo et al., 2009), being known from fewer than ten locations from a restricted range, and declining due to coastal development and the spread of invasive alien plants.

History: Helichrysum sordescens was described by Candolle in 1838 based on a specimen collected by J. F. Drège in ‘Alghoa Bay’ on a professional plant-collecting trip in 1835.

Additional specimens seen: South Africa. Eastern Cape. –3325 ( Port Elizabeth ): dunes W of Maitland River Mouth,(– CD) , 3 Feb 1987, O'Callaghan 1369 ( NBG) ; near Humewood, (– DC) , 6 Oct 1949, Theron 634 ( PRE) ; Summerstrand, (– DC) , 27 Feb 2004, Burrows & Burrows 8364 ( PRE) ; Emerald Hill near Port Elizabeth , (– DC) , Bolus, H. 9802 ( BOL) . – 3326 (Grahamstown): Alexandria, Cannon Rocks, (– DA), 17 Sep 1967, Acocks 23,900 ( PRE) ; Alexandria, Bathurst, Bushman River Mouth nr. Kwaai Hoek, (– DA) , 11 Jan 1936, Dyer 3354 ( PRE) ; Boknes, seaward side of Dias Cross on cliff (– DA) , 12 Mar 2011, Haiden 3 ( NBG) ; Alexandria, seaward side of Dias Cross on exposed, dry cliffface (– DA) , 12 Mar 2011, Haiden 4 ( NBG) ; Alexandria Division, Kenton-on-Sea (– DA) , Dec 1949, Leighton 3109 ( BOL) ; Boknes (near Kenton-on-Sea), Diaz Cross site, Kwaaihoek 3, cliff face, (– DA), 12 Dec 1996, Mucina 6190/1 ( PRE) ; Boesmansriviermond, Wood Cape Nature Reserve, Kwaaihoek 1, cliff top (– DA) , 13 Dec 1996, Mucina 6204/1 ( PRE) ; Bathurst, Kasouga River mouth, (– DA) , 22 Sep 1920, Britten 2345 ( PRE) . – 3424 (Humansdorp): Rebelsrus Private Nature Reserve , Thysbaai, between Cape St. Francis and Oyster Bay , (– BA) , 2 Jan 2014, Hutchinson MSB 5080 ( NBG) . – 3425 (Port Elizabeth): Port Elizabeth near Sea View to east, (– AB) , 9 Sep 1960, Acocks 21,445 ( PRE) .– Without precise locality: Port Elizabeth , Drege 16,337 ( SAM) ; Port Elizabeth , Nov 1952, Munro 403 ( PRE) .

Figures

Fig. 8. Achyranthemum sordescens.A. Habit. B. Capitulum and leaves, close up. C. Capitulum and leaves. D. Leaf indumentum (Drège 16337, SAM).E. Distribution. All photographs G.A.