Phymaspermum comptonii Magee and Ruiters, 2016

Ruiters, Ashton K., Tilney, Patricia M., Wyk, Ben-Erik Van & Magee, Anthony R., 2016, Taxonomy of the Genus Phymaspermum (Asteraceae, Anthemideae), Systematic Botany (Basel, Switzerland) 41 (2), pp. 430-456 : 451

15. Phymaspermum comptonii Magee and Ruiters sp. nov.

— TYPE: SWAZILAND. Mbabane (2631): Bomvu ridge (– AA), 25 Mar. 1964, Compton 32016 (holotype: NBG!; isotype: PRE- 2 sheets!)

Multistemmed, densely leafy shrublet, 0.75–1.0 m high. Stems few-branched; branches erect to spreading, sparsely to densely silvery tomentose to villous, sometimes with purplish tinge; fascicles present in leaf axils. Leaves alternate, spreading to erect, 7.0–15.0 × 0.5–1.0 mm, linear when undissected, mucronate, involute, entire to pinnatifid, narrowed into petiole-like base, without secondary basal lobes, sparsely to densely silvery villous on both surfaces, fleshy; basal swelling present, continuous with stem ribs; lobes 3, 4.0–15.0 × 0.5–1.5 mm, linear, mucronate. Capitula discoid, homogamous, terminal, few- to many-headed (10–50), simple to compound corymbs, pedunculate; peduncles 5.0–60.0 mm long, silvery tomentose. Involucre 4.0–6.0 × 3.0–4.0 mm, cyathiform to campanulate, sometimes tapering at the base; involucral bracts 3-seriate, loosely arranged, margins and apices scarious, membranous apices of bracts two and three 0.3–0.5 mm long, villous, brown margins absent, median resin canals present (resulting in a distinct dark red line in the centre of each bract); outer bracts lanceolate, 3.0 mm long, acuminate; middle bracts lanceolate, 3.6–3.9 mm long, acuminate; inner bracts lanceolate, 4.0– 4.3 mm long, acuminate to rounded. Receptacle convex; paleae usually in 2 marginal series, linear to oblong, 4.3–4.6 mm long, rounded, rigid with scarious apices, scarious apices ±1.0 mm long. Disc florets ± 22, without resin canals; corolla 2.4–2.6 mm long, with only glandular trichomes, yellow; tube 1.3–1.4 mm long; limb campanulate, 0.8 mm long (excluding lobes); lobes spreading, 0.6–0.8 mm long, triangular. Anthers ± 3.1 mm long (including apical appendage); apical appendage oblong to lanceolate. Style ± 2.0 mm long (excluding branches); branches ± 0.5 mm long. Cypselas 1.6 × 0.4 mm, oblong to obovate, 10- to 12-ribbed, apical rim thickened, slightly dentate, glandular trichomes present, sparse, scattered, not mucilaginous when soaked, discontinuous resin canals in ribs rarerly present. Figure 18 .

Diagnostic Characters — Phymaspermum comptonii shares the fleshy silver sericeous leaves with P. argenteum , but is here distinguished by the cyathiform to campanulate involucres and lanceolate, loosely appressed involucral bracts with prominent rounded, scarious appendages (involucres narrowly campanulate and involucral bracts tightly apressed with prominent brown margins in P. argenteum ).

Distribution and Ecology — Phymaspermum comptonii is a near endemic of Swaziland, extending slightly over the South African border around Barberton ( Fig. 18F ). It grows in grassland at an altitude of 1,100 –1,700 m. Flowering is from December to May.

Additional Specimens Examined — SOUTH AFRICA. Mpumalanga: 2531 (Komatipoort): Barberton Mountainlands Nature Reserve (–CC), Burrows 8119 ( PRE); Ida Dayer Nature Reserve 38 km SE of Barberton (–CC), Muller 2057 ( PRE) .

SWAZILAND. 2631 (Mbabane): Mbabane Forbes Reef, Ngwenya mountains near Oshoek border with South Africa, Bomvu Ridge old iron ore mine on path to Bushmen cave, on SW slope as one exits excavated part (– AA), Brusse 6335 ( PRE); Bomvu Ridge (– AA); Compton 31199 ( PRE), Compton 28823 ( PRE two sheets) .

Figures

FIG. 18. Phymaspermum comptonii. A. Leaves. B. Capitula. C. Involucral bracts (outermost to innermost series, from left) and single palea (far right). D. Disc floret. E. Cypsela. F. Known geographical distribution. Vouchers: A, E. Compton 31199 (PRE); B. Brusse 6335 (PRE); C, D. Compton 32016 (PRE). Scale: A–B = 4 mm; C–D = 1 mm; E = 500 μm.