Schizolaena parvipetala Randrian.
Creators: name: Lowry II, Porter P.
name: Nusbaumer, Louis
name: Randrianasolo, Armand
name: Schatz, George E.
name: Hong-Wa, Cynthia
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Malvales
Sarcolaenaceae
Schizolaena
Schizolaena parvipetala

description: Schizolaena parvipetala Randrian. & Hong-Wa, spec. nova (Fig. 5).
Typus: MADAGASCAR. Prov. Toliara: Région Anosy, Tolagnaro, Iabokoho, Antsotso, TGK 42, forêt de Bemangidy, 24°35’17’’S 47°08’42”E, 28 m, [2008], fl., Randriatafika 877 (holo-: MO-6564307!; iso-: G!, K!, MO- 6406252!, P [P00722634]!, TEF!).
Schizolaena parvipetala Randrian. & Hong-Wa differs from its most similar congener, S. gereaui Lowry & al., by its ovate to elliptic leaves (vs. elliptic to slightly obovate) with an acumen (5-) 7-14 mm long (vs. 3-6(-12) mm), the presence of two flowers per involucre (vs. one), smaller petals measuring 4-6 × 1.8-2 mm (vs. 10-14 × 7-8 mm), 30 to 40 stamens (vs. 100 to 120) with the filaments 3-3.5 mm long (vs. ca. 1.5 mm), and styles ca. 3.5 mm long (vs. ca. 2 mm).
Shrubs to small trees 2-6 m tall. Twigs glabrous to sometimes sparsely pubescent, with small, roundish lenticels. Leaves ovate to elliptic, medium brown above, light brown below (in dry material), chartaceous, 2-6 × 1.2-2.4 cm, glabrous on both surfaces, base rounded to truncate, margin entire, minutely thickened, slightly revolute and undulate, apex acuminate, acumen (5-) 7- 14 mm long, venation brochidodromous, with 8-12 pairs of alternate to subopposite, abaxially slightly raised secondary veins joined by depressed-rounded arches, midrib slightly canaliculate above, raised below; petiole 3-5 mm long, glabrous to sparsely stellate-strigose; stipules 2, united at their base, brownish when dry, lanceolate, 2-3.5 × 1-1.5 mm, membranaceous, somewhat triplinerved, glabrous on adaxial surface, stellate on abaxial surface, base truncate, margin entire, apex acute to rounded, caducous, leaving a small scar. Inflorescences axillary, 2-4-flowered, with 1 or 2 unbranched axes, each with a pair of basally connate bracts borne in the middle and bearing 2 terminal flowers, axes 2-3 mm long in bud, reaching 8 mm long at anthesis, densely short stellate, bracts brownish, widely ovate, 1 × 1.2 mm, base truncate, glabrous on adaxial surface, densely stellate on abaxial surface, membranaceous, caducous, leaving a rimmed scar, margin entire, apex rounded, ultimate axes below the involucre 1.5-4.5 mm long, densely stellate, involucre in flower a shallowly 5-lobed rim, densely papillose stellate on both surfaces, subtending 2 sessile flowers, lobes minutely crenate; sepals 3, imbricate, broadly ovate, adaxially concave, 3-4 × 2.5-2.8 mm at anthesis, glabrous on adaxial surface, densely stellate on the exposed part of the abaxial surface, the portion hidden by the overlapping adjacent sepal glabrous and darker-colored, base truncate, margin entire, apex acute to rounded, occasionally shallowly bifid; petals 5, white, oblong, chartaceous (in dry material), 4-6 × 1.8-2 mm, glabrous on both surfaces, base truncate, margin entire, apex rounded, caducous; disc cupuliform, denticulate, 0.8-1 mm long; stamens 30 to 40, filaments slender, often contorted in dry material, 3-3.5 mm long, glabrous, anthers ovoid to subglobose, 0.3-0.4 mm long, introrse, dehiscent through longitudinal slits; ovary ovoid to subglobose, 1.5-2.5 × 2 mm, densely white tomentose, 3-locular, style cylindrical, contorted in dry material, ca. 3.5 mm long, stigma terminal, truncate to slightly 3-lobed, glabrous. Fruit unknown.
S. parvipetala S. gereaui
Distribution and Ecology. – Schizolaena parvipetala, like S. charlotteae described above, appears to be restricted to lowland humid forest of southeastern Madagascar, where it has been recorded to the W of Mahatalaky and at Bemangidy-Ivohibe in the Tsitongambarika New Protected Area, respectively ca. 20 and 55 km N of Tolagnaro (Fig. 3).
Conservation status. – Schizolaena parvipetala is known from only two localities, one of which (Bemangidy-Ivohibe) currently has temporary protection (but see the assessment of Schizolaena charlotteae above) while the other (W of Mahatalaky) lacks any protection. Therefore, with an AOO of ca. 20 km 2 and projected continuing decline as a result of forest conversion and degradation at the second location, S. parvipetala can be assigned a risk of extinction of “Endangered” [EN B2ab(ii,iii,iv,v)] following IUCN Red List Categories and Criteria (IUCN, 2012).
Notes. As its name suggests, Schizolaena parvipetala stands out by having the smallest flowers of any member of the genus. It closely resembles S. gereaui, which also occurs in south-eastern Madagascar, and specimens would be identified as that species using the key provided by LOWRY & al. (1999). However, S. parvipetala differs by several foliar and floral characters, as summarized in Table 2.
Paratypes. – MADAGASCAR. Prov. Toliara: Région Anosy, Tolagnaro, Iabokoho, Antsotso, TGK 42, forêt de Bemangidy, 24°35’17’’S 47°08’42’’E, 28 m, s.d., fl., Randriatafika 876 (MO- 6407630, P [P00722635], TAN); Mahatalaky, Farafara Vatambe, forêt humide de basse altitude de Farafara Andohavolo située au S du village de Farafara, 24°51’05’’S 47°00’07’’E, 179 m, 19.II.2009, fr., Rakotovao 4343 (G!, K!, MO-6404251, P [P00722636], TAN, WAG!).
description: Published as part of Lowry II, Porter P., Nusbaumer, Louis, Randrianasolo, Armand, Schatz, George E. & Hong-Wa, Cynthia, 2014, Endemic Families of Madagascar. XIII. New, restricted range species of Eremolaena Baill. and Schizolaena Thouars (Sarcolaenaceae), pp. 183-193 in Candollea 69 (2) on pages 190-192, DOI: 10.15553/c2014v692a11, http://zenodo.org/record/5770665