Nolletia tenuifolia Mattfeld (1921: 394)

Herman, Paul P. J., 2013, Cypsela morphology in the genus Nolletia (Asteraceae, Astereae) and a revision of the genus, Phytotaxa 122 (1), pp. 1-44 : 13-14

3. Nolletia tenuifolia Mattfeld (1921: 394) ; Merxmüller (1967: 120); Gibbs Russell et al. (1984: 125; 1987: 216); Herman (1993: 714; 2003: 261); Craven (1999: 162); Klopper et al. (2006: 142). Type:— NAMIBIA. Okahandja, Buschsteppe, (QDS: 2116DD Okahandja), 21 April 1913, Engler 6479 (holotype K, e!).

Densely leafy, compact, dwarf or small shrub up to 0.45 m high, branched low down into elongated, sparsely branched upper parts. Older branches dark to reddish brown, light brown upwards and finally young branches green, ribbed; densely stipitate-glandular and sometimes with a few scattered, spreading hairs. Leaves alternate, sessile, linear, (7–)10–30(–35) × 0.5–1.5 mm; apex obtuse to acute; margin entire; stipitateglandular and with some scattered, spreading hairs. Capitula heterogamous, disciform, 8–10 mm in diameter, solitary, terminal, pedunculate. Peduncle stipitate-glandular and with a few spreading hairs. Involucre campanulate. Involucral bracts in ca. 4 rows, imbricate, sometimes with purplish tinge, mostly with yellow oil sacs along midline; outer bracts narrowly ovate to narrowly oblong, 1.5–2.0(–2.5) × 0.2–0.5 mm, acute, sometimes with tuft of fimbrillate hairs, margin entire to fimbrillate, glabrous or with a few scattered, spreading hairs, with some glandular hairs; second row narrowly oblong to narrowly obovate, 2.0–2.5(–3.0) × 0.5–0.8 mm, acute, margin narrowly membranous, fimbriate, glabrous or sometimes with a few scattered, spreading hairs along the midline, sparsely glandular-hairy; third row narrowly obovate, 2.8–3.5 × 0.5–1.0 mm, acute, with narrow membranous, fimbriate margin, glabrous or sometimes with a few spreading hairs along the midline, sparsely glandular-hairy; inner row narrowly obovate to almost linear, 2.5–3.5(–4.0) × 0.2– 0.8 mm, acute, with broader, membranous, fimbriate margin, glabrous or with a few spreading hairs along the midline, sparsely glandular-hairy. Receptacle epaleate. Outer female florets 27–40, in 1 row, fertile, shortly radiate; tubular below, tube 1.5–2.0 mm long; limb short, 0.3–0.5 mm long, longer than style furcation but shorter than or as long as style branches, entire or mostly 3-lobed; corolla yellow, sometimes flushed purplish, with glandular hairs. Style 2.0– 2.5 mm long, bifurcate; style branches narrowly elliptic, 0.5–0.8 mm long; stigmatic areas marginal, confluent at apex, rarely apex with short deltoid-penicillate apical appendage. Cypsela and pappus as in disc florets. Disc florets 63–80, regular, bisexual, fertile; tubular below, tube 1.0– 1.5 mm long, widening upwards, upper, campanulate part 1.0– 2.5 mm long; 5-lobed, lobes 0.5 mm long, sometimes with embedded resin ducts along margins; corolla yellow, rarely flushed purplish, with glandular hairs on tube and lobes. Anthers 1(–2) mm long; with narrowly ovate to narrowly triangular, apical appendage; base shortly calcarate, ecaudate; filament collar with thickened cell walls. Style up to 3 mm long, bifurcate; style branches oblong, 0.5–1.0 mm long, with deltoid-penicillate apical appendage; stigmatic areas marginal. Cypsela pale brownish, obovoid, 0.5–1.5 mm long ( Fig. 1B ), with thickened margin; covered with longish twin hairs, more or less equal in length, apices of twin hairs often broadened; epicarpic cells oblong, arranged in parallel rows ( Fig. 2B ). Pappus of many barbellate bristles in 1 row, 2–3 mm long. Flowering time: from August to March (May).

Distribution and habitat: —Central Namibia ( Fig. 6 ), a Namibian endemic (Craven & Vorster 2006), growing in gravelly soil, schist on mountain slopes, riverbanks, in grassveld. Until now thought to be confined to the Windhoek area (Quarter Degree Squares 2216 and 2217) but a few specimens recorded north and south of this area. According to Craven & Loots (2002) the Red List status of this taxon is DD (Data Deficient), most probably because of misidentifications and uncertainty about the clear circumscription of the species.

Discussion:—After a search of the major European herbaria, Dinter 2228 listed by him (Dinter 1919) for this taxon, Chrysocoma ciliata , could not be located.

Figures

FIGURE 1. Cypselae of Nolletia species as seen under the stereomicroscope: (A) N. gariepina (Warren 78, PRE); (B) N. tenuifolia (Giess 10863, PRE); (C) N. ciliaris (Jacot Guillarmod 377, PRE); (D) N. jeanettae (Bester 8534, PRE); (E) N. welmaniae (Winter 7649, PRE); (F) N. rarifolia (Van Hoepen 1825, PRE); (G) N. ruderalis (Compton 27385, PRE); (H) N. vanhoepeniae (Koekemoer 3899, PRE); (I) N. zambesica (Maguire 1693, PRE); (J) N. chrysocomoides (Merxmüller & Giess 3579, PRE); (K) N. annetjieae (Van Rooyen 3714, PRE). Photographs by P.P.J. Herman.

FIGURE 2. Scanning electron micrographs of cypsela features in Nolletia: (A) obovoid cypsela of N. gariepina (Dinter 3577, PRE); (B) oblong epicarpic cells arranged in regular rows and twin hairs on the cypsela of N. tenuifolia (Dinter 7889, PRE); (C) oblong epicarpic cells arranged in regular rows and twin hairs with acute apices on the cypsela of N. gariepina (Zietsman & Zietsman 794, PRE); (D) oblong epicarpic cells arranged in regular rows and twin hairs with broadened apices in cypsela of N. annemarieae (Moss & Jacobsen K180, PRE); (E) obovoid cypsela in the dried state of N. chrysocomoides showing the ‘pocked’ surface (Germishuizen 7763, PRE); (F) circular epicarpic cells each with a twin hair on the cypsela of N. vanhoepeniae in the dried state (De Beer B5, PRE); (G) circular epicarpic cells each with a twin hair, in N. vanhoepeniae in the rehydrated state (De Beer B5, PRE); (H) paired circular to elliptic epicarpic cells with one twin hair between each pair, scattered over the cypsela surface in N. annetjieae in the dried state (Leistner 1581, PRE). Photographs by P.P.J. Herman.

FIGURE 6. Known geographical distribution of N. tenuifolia (̝) and N. jeanettae (●).