Callilepis corymbosa P.P.J.Herman & M.Koekemoer, 2014

Herman, Paul P. J. & Koekemoer, Marinda, 2014, Two new species of Callilepis (Asteraceae) from southern Africa with corymbose inflorescences, Phytotaxa 183 (4), pp. 254-262 : 254-258

Callilepis corymbosa P.P.J.Herman & M.Koekemoer , sp. nov. ( Figs. 1 , 2A, B )

Similar to Callilepis leptophylla but capitula arranged in terminal, many-headed corymbs, involucral bracts imbricate, ovate, acute, disc florets white, cypselae glabrous except for a mixture of long twin hairs and multicellular hairs along the ribs, leaves linear, 1–2 mm broad and leaf margins distantly denticulate in upper part.

Type:— SWAZILAND. Lubombo Province: SE of Sitsatsaweni at the top of the Mnyame River Gorge, (QDS: 2632 AC; GPS: 26°27’34”S 32°5’43”E), 24 November 2002, Koekemoer 2596 (holotype PRE!, isotypes BNRH, MO, US) .

Perennial herb with several erect, glabrous stems up to 1.2 m high produced from underground rootstock, unbranched basally, branching corymbosely upwards. Leaves alternate, linear, up to 65 × 1–2 mm, decreasing in size upwards, apex acute to acuminate, base cuneate, margin entire to distantly denticulate in upper half, main vein prominent on lower surface, glabrous. Capitula heterogamous, radiate, up to ± 26 arranged in loose corymbs terminally. Involucre obconical to subglobose, 8 mm long, 8–10 mm in diameter across mouth of involucre. Involucral bracts in 4 or 5 rows, imbricate, outer shorter than inner, straw-coloured, glabrous; outer row ovate, 3–4 × 1.5–1.8 mm, apex acute, mucronulate, with dark central strip broadening towards apex, margins fimbriate; second row ovate, 4.0–4.5 × 2 mm, apex acute, mucronulate, with dark central strip broadening towards apex, margins fimbriate; third row ovate, 4.5 × 2 mm, apex acute, mucronulate, with dark central strip slightly broadening towards apex, margins fimbriate; inner rows ovate, oblong to obovate, 5 × 1.5–2.5 mm, apex acute, mucronulate, with dark central strip, margins fimbriate. Receptacle conical, paleate, paleae boat-shaped, keeled, 5.5–6.0 × 2 mm, straw-coloured, with dark midline, apex acute, margins fimbriate, with few longish hairs along keel, enveloping disc florets. Ray florets female, fertile, up to 15; tube 2.0– 2.5 mm long, with staminodes; limb oblong-elliptic, 6.5–7.5 × 3–4 mm, apex 3-dentate; corolla glabrous, white. Style 2.8–3.5 mm long, bifurcate, style branches 0.3–0.5 mm long, linear-elliptic, obtuse, stigmatic areas marginal, confluent at apex. Cypselae (immature) greyish purple, obconical, 3-angled, 2.5–3.0 × 1 mm, glabrous except for a mixture of long twin hairs and multicellular hairs along ribs. Pappus (immature) dimorphic, consisting of 3 straw-coloured awns arising from tips of cypsela ribs, one 3.5 mm long, usually longer than other two, other two 3 mm long; interspersed with 3 oblong, lacerated, chartaceous scales, 1.0–1.5 × 0.2–0.5 mm. Disc florets regular, bisexual, fertile, tubular below, slightly widening upwards towards lobes, tube 2.5–3.0 mm long, 5-lobed, lobes 1.5–2.5 mm long; corolla glabrous, white. Anthers 5, 1.0– 1.5 mm long, with ovate apical appendages 0.5 mm long, base calcarate and caudate, tails ± 1 mm long, hairy. Style 3.5 mm long, bifurcate, style branches 0.8–1.0 mm long, linear, stigmatic areas marginal, confluent at apex, apex conical with papillae outside at base of cone. Cypselae (immature) greyish purple, obovate, 3–4 × 1.0– 1.2 mm, laterally compressed, occasionally weakly 3-angled, usually with midrib on one surface, glabrous except for mixture of long twin hairs and multicellular hairs along edges. Pappus (immature) dimorphic, consisting of 2, sometimes 3, straw-coloured awns up to 3.5 mm long interspersed with 3 or 4 oblong, lacerated, chartaceous scales 1.5–2.0 × 0.4–0.5 mm ( Fig. 3A, B ). Flowering time: November (late spring to early summer).

Distribution:—Currently only known from the type collection from Swaziland ( Fig. 4 ) and it seems to be endemic there.

Discussion:—— Callilepis corymbosa differs from C. leptophylla Harvey (1865: 136) , which has filiform entire leaves, the capitula are much larger (up to 20 mm in diameter across the mouth of the involucre) and solitary, the involucral bracts are linear-filiform, subequal, the disc florets are dark purple, the cypselae are glabrous and the pappus consists of 3 (ray cypselae) or 2 (disc cypselae) rigid awns ( Figs. 2C, D , 3C, D ).

Etymology:—The specific epithet refers to the capitula which are arranged in terminal corymbs.

Figures

FIGURE 1. Scanned image of holotype of Callilepis corymbosa P.P.J.Herman & M.Koekemoer (Koekemoer 2596, PRE).

FIGURE 2. Callilepis corymbosa (A. habit, B. corymbose inflorescences), C. leptophylla (C. habit, D. single capitulae). Photographs by M. Koekemoer.

FIGURE 3. Cypselae and pappi of Callilepis species as seen under the stereomicroscope: C. corymbosa (A. ray cypsela, B. disc cypsela, Koekemoer 2596, PRE), C. leptophylla (C. ray cypsela, D. disc cypsela, Pole Evans 401, PRE) and C. normae (E. ray cypsela, F. disc cypsela, Koekemoer 4573, PRE). Photographs by P.P.J. Herman.

FIGURE 4. Known geographical distribution of Callilepis corymbosa (●) and C. normae (■) in southern Africa.