Monotes hypoleucus var. discolor (R.E.Fr.) Meerts, 2017

Meerts, Pierre, Rougelot, Quentin & Sosef, Marc, 2017, Revision of the genus Monotes (Dipterocarpaceae) in D. R. Congo, with implications for Angola and its distinction from Marquesia, Phytotaxa 308 (2), pp. 151-205 : 188

9d. Monotes hypoleucus var. discolor (R.E.Fr.) Meerts , comb. et stat. nov. Basionym: Monotes discolor Fries (1914b: 153 , t. 12 fig. 13–14); Bancroft (1937: 141; 1939a: 342, 378); De Wildeman (1927a: 172);

Duvigneaud (1949: 50; 1961: 416); Engler (1921: 520); Exell & Mendonça (1951: 371); Figueiredo & Smith (2008: 67); Lebrun &

Stork (1991: 144); Meerts (2016: 223); White (1962: 262; fig. 46A). Type : — ZAMBIA. Mporokoso, 31 October 1911, Fries 1175 (holo-: S!; iso-: UPS) .

Diagnosis:— Differs from the type variety by the following traits: petiole longer, 18–40 mm (vs. 9–21 mm); fruit bigger,> 15 mm in diameter (vs. 10–15 mm), sepals longer (4–5 mm (vs. ca 3 mm); upper surface of leaf glabrous, markedly reticulate, often more or less shiny.

Small tree up to 12 m high; branchlets pubescent, soon becoming glabrous. Leaf: petiole 20–40 mm long, ca. 3 mm in diameter; blade broadly elliptic to obovate or suborbicular, 13–21 × 8–13.5 cm, less than twice as long as wide, rounded or more often cordate at the base, rounded, truncate or emarginate at apex; upper surface green to yellowish-green, not turning brown in herbarium, finely reticulate, somewhat shiny, with numerous spherical yellow glands, glabrous except for the midrib; lower surface strikingly discolorous, whitish to cream, cottony-tomentose with curled or coiled hairs on the nerves and reticulation and completely hiding the reticulation and interreticular areoles, which are densely covered with minute stellate hairs, more rarely ( f. cordatus ) long hairs almost lacking and stellate hairs covering all the surface; midrib and lateral nerves slightly depressed above and very prominent beneath; lateral nerves in 16–21 pairs, curving towards the apex without reaching the margin of the leaf. Inflorescences axillary on young short leafy shoots; peduncles 3–8 cm long, relatively few-flowered and lax, densely rufous-tomentose. Flower: pedicel ca. 3 mm long, sepals 4–5 mm long, densely cottony-greyish-tomentose; petals ca. 10 mm long, densely fulvous-sericeous-tomentose; stamens with connective produced in a long triangular-oblong lobe ca. half as long as anther. Fruit 20 mm in diameter, subglobose, ± truncate and apiculate at the apex; wings 4.5–5.5 × 1–2 cm, brownish, spathulate, with sparse minute fasciculate hairs outside and inside.

Variation: — Var. discolor is variable in the indumentum on lower surface of the leaf and two forms can be distinguished.