Phymaspermum oppositifolium 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 : 443-444

8. Phymaspermum oppositifolium Magee and Ruiters sp. nov.

— TYPE: SOUTH AFRICA. Eastern Cape, Steytlerville (3324): Kouga Mountain , Riverside (–CD), 20 January 2000, Eusten-Brown 02 (holotype: NBG!)

Single-stemmed, densely leafy shrub, 1.5 m high. Stem much-branched; branches erect to spreading, glabrous; fascicles present in leaf axils. Leaves opposite, closely imbricate, appressed to sometimes erect, 2.0–5.0 × 1.0–2.0 mm, lanceolate, acute to acuminate, sometimes mucronate, entire, without petiole-like base, without secondary basal lobes, glabrous on both surfaces, bony; basal swelling present, continuous with stem ribs. Capitula radiate, heterogamous, terminal on short axillary shoots, solitary, with 0–3 additional capitula from leaf axils below, prominent peduncles absent. Involucre 5.0–6.0 × 4.0–5.0 mm, funnel-shaped, tapering at the base; involucral bracts 4-seriate, tightly arranged, margins and apices scarious, membranous apices of all bracts 2.4–2.5 mm long, scarious texture, brown margins absent, median resin canals present; outer bracts lanceolate, 3.4 mm long, acute; middle bracts lanceolate, 4.0– 4.5 mm long, acute; inner bracts lanceolate, 5.5 mm long, rounded. Receptacle convex; paleae in marginal series, linear, ± 4.0 mm long, rounded, scarious. Ray florets ± 8; tube 1.5 mm long; limb ovate to obovate, 4.8 × 2.3 mm, apically 3-dentate, white to purple. Disc florets ± 20, without resin canals; corolla 2.0 mm long, with only glandular trichomes, yellow to purple; tube 0.8 mm long; limb narrowly campanulate, 1.0 mm long (excluding lobes); lobes erect, ± 0.4 mm long, triangular. Anthers 2.4 mm long (including apical appendage); apical appendage ovate. Style ± 2.0 mm long (excluding branches); branches ± 0.3 mm long. Cypselas 1.9 × 0.6 mm, narrowly obovate, ribbed, apical rim thickened, entire, brown, glandular trichomes present, distribution unknown, discontinuous resin canals in ribs absent. Figure 11 .

Diagnostic Characters — Phymaspermum oppositifolium is the only opposite leafed species within the genus. It shares the appressed leaves, entirely scarious involucral bracts and purplish ray florets with the closely related P. appressum from which it can be distinguished further by the funnel-shaped involucres and lanceolate involucral bracts.

Distribution and Ecology — This species is known only from the type collection in the Kouga mountains of the Eastern Cape ( Fig. 11G ), where it was collected at an altitude of 250 m. It was found flowering in January and the collector noticed seeing very few plants (Eusten-Brown pers. comm.).

Figures

FIG. 11. Phymaspermum oppositifolium. A. Leaf. B. Capitula. C. Involucral bracts (outermost to innermost series, from left) and single palea (far right). D. Disc floret. E. Ray floret. F. Cypsela. G. Known geographical distribution. Voucher: A–F. Eusten-Brown 02 (NBG). Scale: A–B = 4 mm; C–D = 1 mm; E = 500 μm.