Phymaspermum thymelaeoides, 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 : 439

3. PHYMASPERMUM THYMELAEOIDES (DC.) Magee & Ruiters comb. nov. Osteospermum thymelaeoides DC., Prodr. 6: 462 (1838).

— TYPE: SOUTH AFRICA. Western Cape, Beaufort West (3222): ‘ Nieuvewelbergen ’ [Nieuwveld mountains] (–AB), Oct 1826, Drège 6177 (holotype: G –DC–image!; isotypes: P-image!, two sheets) . [Note: de Candolle was uncertain about the placement of this taxon in Osteospermum . Norlindh (1943) in his revision of Osteospermum , recognised that O. thymelaeoides was rather a species of Phymaspermum but incorrectly considered it to be synonymous with Phymaspermum parvifolium . On closer examination the specimen clearly matches P. schroeteri with the openly branched habit and sericeous leaves and involucral bracts. As O. thymelaeoides is the older name it has priority and P. schroeteri is therefore reduced into synonomy. This is the only specimen of this species in de Candolle’ s herbarium at G –DC.]

Phymaspermum schroeteri Compton in Trans. Roy. Soc. South Africa 19: 320 (1931); Källersjö in Nordic J. Bot. 5(6): 535 (1986); K. Bremer and Humphries in Bull. Nat. Hist. Mus. Lond. (Bot.) 23(2): 94 (1993); Germish. and N. L. Meyer, Pl. S. Afr.: 274 (2003); Klopper et al. Checklist of the flowering plants of Sub- Saharan Africa: 147 (2006); Germish. et al. Checklist S. African Pl.: 243 (2006). syn. nov.

— TYPE: SOUTH AFRICA. Western Cape, Montagu (3320): Ngaap Kop (–BA), 27 Sept. 1926, Compton 3065 (holotype: BOL!) .

Single-stemmed, densely leafy shrub, (0.5) 0.8–1.2 m high. Stem much-branched; branches erect to spreading, silvery pubescent; fascicles sometimes present in leaf axils. Leaves alternate, erect to spreading, 5.0–30.0 × 0.8–3.0 mm, linear to spathulate, mucronate, entire to trifid, narrowed into petiole-like base, sometimes with secondary basal lobes, silvery sericeous on both surfaces, fleshy; basal swelling present, continuous with stem ribs; lobes 3, 2.0–3.0 × 1.0 mm, linear, mucronate. Capitula radiate, heterogamous, terminal, solitary, with 0–2 additional capitula from leaf axils below, pedunculate; peduncles 5.0–35.0 mm long, silvery pubescent. Involucre 4.0–7.0 × 4.0–5.0 mm, hemispherical to cyathiform, sometimes tapering at the base; involucral bracts 3- or 4-seriate, loosely to tightly arranged, margins and apices scarious, membranous apices of all bracts 0.1–1.0 mm long, silvery villous, brown margins absent, median resin canals present; outer bracts lanceolate, 1.5–2.1 mm long, attenuate; middle bracts lanceolate, 2.0– 2.3 mm long, rounded; inner bracts oblong, 2.7–3.8 mm long, rounded; innermost bracts oblong, 3.4–4.0 mm long, rounded. Receptacle convex; paleae in marginal series (rarely rudimentary inner paleae present); oblong, 3.5–4.0 mm long, rounded, scarious. Ray florets 8–12; tube 1.2–1.6 mm long; limb obovate, 5.4–7.2 × 2.2–3.0 mm, apically 3-dentate, white to purple. Disc florets 20–30, without resin canals; corolla 1.7–2.7 mm long, with glandular trichomes and sometimes hairs on tube, yellow to purple; tube 0.7–1.8 mm long; limb campanulate, 0.5–1.0 mm long (excluding lobes); lobes spreading, 0.5–1.0 mm long, triangular. Anthers 1.7–3.8 mm long (including apical appendage); apical appendage ovate. Style 1.2–3.2 mm long (excluding branches); branches 0.4–0.5 mm long. Cypselas 2.5 × 0.7 mm, obovate, 11-ribbed, apical rim thickened, slightly dentate, glandular trichomes present, dense, mostly between ribs, mucilaginous when soaked, discontinuous resin canals in ribs absent. Figure 6 .

Diagnostic Characters — Phymaspermum thymelaeoides is an openly branched shrub, more than 0.8 m tall, with radiate heads, usually hairy disc floret tubes, and entire, spathulate leaves. It can be distinguished from P. leptophyllum by the spathulate, silvery sericeous leaves and the ribbed cypselas with prominently stalked myxogenic trichomes. Similarily silvery leaves are found in P. trifidum but in P. thymelaeoides the leaves are largely entire and the innermost involucral bracts have a much shorter membranous appendage.

Distribution and Ecology — Phymaspermum thymelaeoides occurs on upper south facing slopes, at altitudes of 1,000 – 1,700 m, from Ghaapkop near Laingsburg along the Roggeveld and Nuweveld mountains to Molteno Pass ( Fig. 6G ). Flowering appears to be throughout the year. The species is well grazed (Shearing 1159, PRE; Shearing 1181, PRE; Acocks 17199, PRE) and the flowers have a prominent honey scent.

Additional Specimens Examined — SOUTH AFRICA. Northern Cape: 3221 (Merweville): Oudekloof Bo , Oukloof (– BB), Shearing 941 ( PRE), Shearing 1159 ( PRE) ; Fraserburg, Layton Vergenoegd (– BB), Acocks 23538 ( PRE) ; Layton flats, Vlak Camp (– BB), Acocks 23538 ( PRE). Western Cape: 3221 (Merweville): Nuweveld mountains, Uitspannings River Pass , 40 km NW of Merweville (– CA), Brusse 3409 ( BOL) ; Sutherland, Besemgoedberg on Komsberg escarpment (– CA), Acocks 17199 ( PRE). 3222 ( Beaufort West ): Nieuwveld mountains (–AB), Esterhuysen 2746 ( BOL) ; Nieuweveld mountains, next to Molteno Pass , between entrance gates to farms Highlands and Rhenosterveld (– BA), Vlok 2527 ( PRE) ; Theekloof (– BA), Acocks 14151 ( PRE). 3320 (Montagu): Boerhoeuer farm, between Matjiesfontein and Sutherland (– BA), Magee and Boatwright 381 ( NBG) ; Ghaap Kop, Laingsburg (– BA), Compton 14421 ( NBG), Shroeter 18591 ( BOL) ; Ghaap Kop, Laingsburg , Whitehill (– BA), Compton 4427 ( BOL, NBG), Esterhuysen 3270 ( BOL) .

Figures

FIG. 6. Phymaspermum thymelaeoides. A. Leaf. B. Capitula. C. Involucral bracts (outermost to innermost series, from left) and single palea (far right). D. Ray floret. E. Disc floret. F. Cypsela. G. Known geographical distribution. Vouchers: A, F. Shearing 941 (PRE); B–E. Magee and Boatwright 381 (NBG). Scale: A–B = 4 mm; C–D = 1 mm; E = 500 μm.