Thursday, October 17, 2019

[Botany • 2019] Synsepalum chimanimani (Sapotaceae) • A New Species from the Chimanimani Mountains of Mozambique and Zimbabwe, with Notes on the Botanical Importance of This Area

Synsepalum chimanimani S.Rokni & I.Darbysh.

in Rokni, Wursten & Darbyshire, 2019.

Synsepalum chimanimani S.Rokni & I.Darbysh., sp. nov., a small tree endemic to the forests of the southern foothills of the Chimanimani Mountains of Mozambique and Zimbabwe, is described and illustrated. The differences in morphology and distribution between the new species and the related S. kaessneri and S. muelleri, with which it has been confused, are clarified. The new species is globally Endangered due to ongoing habitat loss within its restricted range. The botanical importance and conservation of the Chimanimani foothills is also discussed, and they are highlighted as a candidate Important Plant Area.

Keywords: conservation, herbarium, Important Plant Area, Makurupini, taxonomy

Figure 1. Synsepalum chimanimani (A-K) and Synsepalum kaessneri (L)
A habit B stem apex with apical buds/young leaves and petioles showing indumentum C medifixed hairs on stem D abaxial leaf surface showing sparse medifixed hairs on midrib E leaf showing (faint) secondary veins F flower cluster showing bud, open flower and partially opened flower G flower, side view (hydrated) H corolla after removal of two petals and stamens (hydrated) I stamen and staminodes in situ on petal, inner face bases of neighbouring petals shown J side view of stamen and petal (staminodes omitted) K immature fruit (from photograph) 
L leaf (abaxial) of Synsepalum kaessneri

A, D-K drawn from B.T. Wursten BW897 (BR0000020700003) B, C from Timberlake et al. 6197 (K001291035) L drawn from Magogo & Glover 280 (K). Scale bars: 1mm (Single bar); 2 mm and 5 mm (graduated single bar); 1 cm (double bar); 5 cm (graduated double bar). 
Drawn by Andrew Brown, November 2018.

Figure 2. Synsepalum chimanimani 
A habit and leaves B, C flowering stems D flowers E immature fruit
(Photographs by Bart Wursten).

Synsepalum chimanimani S.Rokni & I.Darbysh., sp. nov.

Diagnosis: This species differs from Synsepalum kaessneri (Engl.) T.D.Penn. in the generally smaller (7.9–12.6 x 1.7–3.4 cm versus 9.8–16.7 x 2.8–5.2 cm) narrowly elliptic leaves with a long and narrow acuminate tip versus oblanceolate leaves with a short and broad acuminate tip (see illustration, Fig. 1E, L); flowers sessile or almost so with pedicels less than 1 mm long (extending to 2 mm long in fruit) versus flowers stalked with pedicels 1–3 mm long (extending to 3–5 mm in fruit); shorter corolla tube (0.75–0.8 mm long versus 1.2 mm long) and shorter (1.45–1.5 mm versus 1.8–1.9 mm), broadly ovate versus ovate corolla lobes; anthers with elliptic thecae with a minute, inconspicuous point at the apex of the connective versus arrow-head shaped anthers with oblong thecae with a conspicuous apiculate apex to the connective. Table 1 shows the distinguishing characters between the two species.

Etymology: The specific epithet is taken from the Chimanimani mountains to which the species is confined.


 Saba Rokni, Bart Wursten and Iain Darbyshire. 2019. Synsepalum chimanimani (Sapotaceae), A New Species from the Chimanimani Mountains of Mozambique and Zimbabwe, with Notes on the Botanical Importance of This Area. PhytoKeys. 133: 115-132. DOI: 10.3897/phytokeys.133.38694