Oxandra rheophytica 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 : 248-251

19. Oxandra rheophytica Maas & Junikka , sp. nov. — Fig. 19; Map 10

Ab omnibus speciebus foliis linearibus differt. — Typus: Callejas et al. 9343 (holo U; iso HUA), Colombia, Antioquia, Mun. Puerto Berrío, Vereda Bodegas,sitio San Juan de Bedout , Quebrada de San Juan , 300 m, 4 Mar.1990 .

Shrub 2–3 m tall; young twigs glabrous, grooved. Leaves: petiole 1–3 mm long, 1 mm diam; lamina linear, 7–11 by 1–1.5 cm (leaf index 9–10), chartaceous, sparsely, but distinctly verruculose below, dull and greyish above, brown below, glabrous above and below, base obtuse, oblique, apex long-acute, primary vein raised above, secondary veins indistinct, 12–15 on either side of primary vein, slightly raised above, angle of secondary veins with primary vein 50–70°, smallest distance between loops and margin c. 1 mm, tertiary veins flat above, reticulate. Flowers solitary; pedicels 1–2 mm long, 1 mm diam, glabrous; bracts 4–5, depressed ovate, 1–1.5 mm long, outer side glabrous; flower buds globose; sepals broadly ovate, c. 2 by 2 mm, outer side glabrous; petals colour in vivo not recorded, oblong-elliptic, c. 6 by 4 mm, outer side glabrous; stamens c. 25, 1–1.5 mm long, apex of connective depressed ovate; carpels ≤ 5. Monocarps (immature) c. 5, green, black in sicco, ellipsoid, 7–8 by 4–5 mm, glabrous, apex rounded, wall not measurable, stipes absent. Seed not seen.

Map 10 Distribution of Oxandra rheophytica (●), O. riedeliana (●) and O. saxicola (▲).

Fig. 19 Oxandra rheophytica Maas & Junikka. Flowering twig (Callejas et al. 9343, iso HUA).

Fig. 20 Oxandra riedeliana R.E.Fr. Flowering twig (Amaral et al. 686, U).

Distribution — Colombia (Antioquia).

Habitat & Ecology — In humid, periodically inundated forest. At elevations of 150–300 m. Flowering: March; fruiting: October.

Other specimen studied. COLOMBIA, Antioquia, Mun. Puerto Berrío, via Puerto Berrio-Yondó, 3.5 km NE of Puerto Berrio , sitio Bodegas , Quebrada San Juan de Bedout , 150 m, Callejas & Cardona 12558 ( HUA) .

Note — Oxandra rheophytica has extremely narrow, linear leaves and matches O. xylopioides in that aspect. It differs, however, by the leaf base which lacks the tooth-like prolongations of O. xylopioides and by the sparse presence (instead of very dense) of verruculae on the leaves. The epithet ‘rheophytica’ refers to the habitat in borders of streams (Greek ρέος = stream; ῳΎΤον = plant).