Phymaspermum argenteum, Brusse

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 : 450-451

14. PHYMASPERMUM ARGENTEUM Brusse in Bothalia 19: 29 (1989); K. Bremer and Humphries in Bull. Nat. Hist. Mus. Lond. (Bot.) 23(2): 94 (1993); Retief and Herman, Pl. N. Prov. S. Afr.: 330 (1997); Germish. and N.L. Meyer, Pl. S. Afr.: 273 (2003); Klopper et al. Checklist of the flowering plants of Sub- Saharan Africa: 147 (2006); Germish. et al. Checklist S. African Pl.: 243 (2006).

— TYPE: SOUTH AFRICA. Limpopo (2429): 18 km from the main Polokwane-Tzaneen road near Boyne to Wolkberg Estates , 1 km from the turn-off to Frosch Farm to Wolkberg Estates (–BB), 30 May 1988, Brusse 5567 (holotype: PRE!; isotypes: BM –image!, B –image!, E –image!, K –image!, M –image!, MO –image!, NBG!, P –image!, S –image!, WAG –image!) .

Multistemmed, densely leafy shrub, 0.3–1.5 m high. Stems few-branched; branches erect, sparsely to densely silvery tomentose; fascicles present in leaf axils. Leaves alternate, spreading, 8.0–18.0 × 0.8–2.0 mm, linear when undissected, mucronate, sometimes revolute, entire to pinnatifid, narrowed into petiole-like base, without secondary basal lobes, sparsely to densely silver villous on both surfaces, fleshy; basal swelling present, continuous with stem ribs; lobes 3–5, 3.0–15.0 × 1.0– 1.5 mm, linear, mucronate. Capitula discoid, homogamous, terminal, few to many-headed (10 to +100), compound corymbs, pedunculate; peduncles 5.0–30.0 mm long, slightly to densely silvery-tomentose. Involucre 5.0–7.0 × 1.8–3.5 mm, narrowly campanulate to cylindrical, tapering at the base; involucral bracts 3- or 4-seriate, tightly arranged, margins and apices scarious, membranous apices of all bracts 0.5–1.0 mm long, glabrous to villous (rarely beyond margins), brown margins dark and distinct, median resin canals present; outer bracts deltoid to lanceolate, 1.7–1.9 mm long, acuminate; middle bracts deltoid to ovate, 2.4–3.1 mm long, acuminate; inner bracts broadly oblong to lanceolate, 2.8–3.8 mm long, acuminate to rounded. Receptacle convex; paleae in marginal series, oblong, linear, 3.8–4.5 mm long, rounded, rigid with scarious apices, scarious apices ± 0.5 mm long. Disc florets 6–23, without resin canals; corolla 2.3–3.1 mm long, with only glandular trichomes, yellow; tube 1.2–1.7 mm long; limb narrowly to broadly campanulate, 1.0– 1.4 mm long (excluding lobes); lobes spreading, 0.7–1.0 mm long, narrowly to broadly triangular. Anthers 2.8–3.4 mm long (including apical appendage); apical appendage oblong to lanceolate. Style 2.0–3.0 mm long (excluding branches); branches 0.2–0.3 mm long. Cypselas 2.0–2.8 × 0.7 mm, oblong, 10-ribbed, apical rim thickened, entire, brown, glandular trichomes present, sparse, scatterred, not mucilaginous when soaked, discontinuous resin canals in ribs absent. Figure 17 .

Diagnostic Characters — Phymaspermum argenteum shares the fleshy, usually silvery sericeous leaves with the closely related P. comptonii , but can be readily distinguished by the narrowly campanulate involucres with closely appressed, deltoid to ovate involucral bracts with prominent dark margins.

Distribution and Ecology — Phymaspermum argenteum occurs from around Polokwane and Zebediela in Limpopo to near Pilgrims Rest in Mpumalanga ( Fig. 17F ). It is found in grassland vegetation in dolomite soils at an altitude of 1,450 –2,080 m. It flowers from May to September.

Additional Specimens Examined — SOUTH AFRICA. Limpopo: 2329 (Polokwane): Iron Crown (–DD), Mathews 896 (PRE). 2429 ( Zebediela ): Mokopane , Makapansgat , “nek” at top of rock gulley (–AA), Maguire 2913 (B–image), near top of Diabase gulley, Maguire 8200 (B–image) ; Ga-Maja, Donkerkloof road off the main Polokwane- Burgersfort road, near Chuniespoort , 1.5 km from the radio masts to Chuniespoort , Farm Stylkop 344KS (–BA), Brusse 5783 (B–image, NBG) ; Bewaarkloof, 3 km from the main Boyne-Wolkberg road to Ashmole Dales , at the Ashmole Dales sign (–BB), Brusse 5611 (B–image, BOL, NBG, NU, WIND) ; Wolkberg, 12 miles SE of Boyne on road to Ashmole Dales (–BB), Codd 10403 (PRE two sheets) ; Farm Paardevlei 201 KS (–BB), Venter 10704 (PRE) ; Wolkberg plateau 14 km SE of Boyne (–BB), Van Vuuren 1533 (K–image, PRE). Mpumalanga: 2430 ( Pilgrims Rest ): Motlatsepoort Dam Reserve , rocky plateau at Motlatsepoort View Point (–DB), Venter 9524 (PRE) ; Road from Pilgrim’ s rest to Bourke’ s Luck , near TGME Sports Club (–DB), Burrows and Manning 9004 (NBG, PRE) ; 31 km from Ohrigstad on road to Pilgrims Rest (–DC), Clark 1239 (PRE) ; Lisbon Falls, Graskop (–DD), Compton 19801 (NBG) ; Lisbon, “ Motlatse ”, on rocky slopes on top of escarpment (–DD), Liebenberg 3555 (PRE) .

Figures

FIG. 17. Phymaspermum argenteum. 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. Brusse 5567 (NBG); B. Burrows and Manning 9004 (NBG); C–E. Brusse 5611 (NBG). Scale: A–B = 4 mm; C–D = 1 mm; E = 500 μm.