Oxandra aberrans Maas & Junikka, 2016

Junikka, L., Maas, P. J. M., Maas-van de Kamer, H. & Westra, L. Y. Th., 2016, Revision of Oxandra (Annonaceae), Blumea 61 (3), pp. 215-266 : 221

1. Oxandra aberrans Maas & Junikka , sp. nov. — Fig. 3 , 4a ; Map 1

Ab omnibus speciebus Oxandrae floribus extra-axillaribus,spongosis differt. — Typus: Kennedy & Breedlove 1422 (holo L), Mexico, Chiapas,km 3 of road from Ocozocoautla to Malpasol , c. 0.6 km up the stream bed toward hill, 2700 ft, 2 Aug. 1972 .

Tree to c. 5 m tall, diam not recorded; young twigs sparsely covered with appressed hairs, soon glabrous. Leaves: petiole 2–3 mm long, c. 0.5 mm diam; lamina narrowly elliptic to elliptic, 4–8 by 1.5–2.5 cm (leaf index 2.5–3.2), chartaceous, not verruculose, dull and green above, glaucous green below, glabrous above, covered with some appressed hairs mainly along primary vein below, base acute and slightly attenuate, apex bluntly acute, primary vein flat to impressed above, secondary veins distinct, 8–10 on either side of primary vein, raised above, angle of secondary veins with primary vein 60–70°, smallest distance between loops and margin 1–2 mm, tertiary veins slightly raised above, reticulate. Flowers solitary, opposite the leaves; pedicels 3–5 mm long, c. 1 mm diam, rather densely covered with appressed hairs; bracts 2, broadly ovate-triangular, 1–1.5 by 1–1.5 mm, outer side rather densely covered with appressed hairs; flower buds globose; sepals broadly ovate-triangular, 1.5–2.5 by 1.5–2.5 mm, outer side rather densely covered with appressed hairs; petals cream to pale green in vivo, ‘spongy’, 1.5–2.5 mm thick in vivo, elliptic, c. 8 by 5 mm, outer side rather densely covered with appressed hairs; stamens c. 50, 1.5–2 mm long, apex of connective depressed ovate; carpels c. 15. Monocarps and seed not seen.

Distribution — Mexico (Chiapas).

Habitat & Ecology — In deciduous forest. At an elevation of c. 900 m. Flowering: August; fruiting: not recorded.

Field observations — Petals thick, spongy, 1.5–2.5 mm thick ( Kennedy & Breedlove 1422).

Note — Oxandra aberrans , only known from the type collection, is unique in the genus by the position of its flowers, which are placed opposite the leaves instead of axillary. Other remarkable features of this species are the low number of bracts (2), and the ‘spongy’, hairy petals.

Figures

Map 1 Distribution of Oxandra aberrans (●), O. asbeckii (●) and O. bolivarensis (▲).

Fig. 3 Oxandra aberrans Maas & Junikka. Flowering branch (Kennedy & Breedlove 1422, holo U).

Fig. 4 a. Oxandra aberrans Maas & Junikka. Detail of flowering branch. — b. Oxandra guianensis R.E.Fr. Detail of fruit. — c. Oxandra krukoffii R.E.Fr. Detail of fruit. — d. Oxandra lanceolata (Sw.) Baill. Detail of flowers. — e–g. Oxandra laurifolia (Sw.) A.Rich. e. Detail of flowers; f. several-flowered inflorescence; g. fruits — h. Oxandra leucodermis (Spruce ex Benth.) Warm. Detail of fruit (a: Kennedy & Breedlove 1422, holo U; b: Hoffman et al. 1463, U; c: Prance et al. 25831, U; d: Proctor 36333, MO; e: Sintenis 4313, U; f: Wright 4, U; g: Zanoni et al. 33142, U; h: Cid et al. 7302, U).