Laxoplumeria aberrans J.F.Morales, 2018

Morales, J. Francisco & Morais, Isa Lucia De, 2018, Studies in the Neotropical Apocynaceae LII: A synopsis of Laxoplumeria with three new species, Phytotaxa 343 (1), pp. 35-46 : 36-39

Laxoplumeria aberrans J.F.Morales , sp. nov. ( Figs. 1 , 6 )

Type: — FRENCH GUIANA. Saul : La Fumée Mountain Trail , Saül, from carbet to base of steep and mean hill, 16 Sep 1989, Mori, Gracie, Angell, Rothman & Lifton-Schwerner 20933 (Holotype, NY!; isotypes, CR!, P!) .

Laxoplumeria aberrans is recognized by its petioles 10–16 mm long, leaf blade ovate to ovate-elliptic, corolla tube 4–6 × 1.5–2.1 mm, corolla lobes 15–17 mm long, and nectary surrounding the ovary.

Trees or shrubs, possible lianas; stems glabrous, with milky sap. Leaves alternate, petioles 10–16 mm; leaf blade (8.5–)11–16 × (4–) 4.5–6.4 cm, obovate to elliptic-obovate, the apex acute to obtuse-apiculate, the base narrowly cuneate, glabrous, with 13–16 pairs of secondary veins. Inflorescences 9–14 cm long, glabrous, peduncles 38–90 mm, pedicels 6–10 mm, bracts up to 0.6 mm; calyx lobes 0.7–0.9 mm, ovate, the apex obtuse to acute, glabrous; corolla greenish yellow, glabrous, tube 4–6 × 1.5–2.1 mm, lobes 15–17 × 1.6–1.8 mm, narrowly elliptic to narrowly ovate-elliptic; stamens inserted in the proximal part of the corolla tube, near the base, anthers 1.7–1.8 mm; ovary 1–1.2 mm, nectary 1.7–1.9 mm, surrounding completely the ovary. Follicles 30–42 × 0.4–0.8 cm, glabrous; seeds 2.8–3 cm, coma 0.4–1.6 cm, tan.

Distribution and habitat: — Endemic to French Guiana, growing in tropical non-flooded moist forest, at 200– 400 m. Flowering in February, April, and September. Fruiting in September and December.

Observations:— Laxoplumeria aberrans resembles L. baehniana and L. tessmannii but it is distinguished by its petioles 10–16 mm long (vs. 10–38 mm), pedicels 6–10 mm long (vs. 1.5–3 mm), and corolla lobes 15–17 mm (vs. 6–7.5 mm long). Three different habits are reported for this species: liana (Mori et al. 20933), shrub (Cremers 8149), and tree (Tostain et al. 1769). Additional fieldwork needs to be done to corroborate if the “liana” habit is real or just a misinterpretation of the collector. In addition, the nectary covers completely the ovary, a feature previously not reported in Laxoplumeria . Although these irregular characters, the fruits and seeds are characteristic of the genus.

Paratypes: FRENCH GUIANA. Saúl : Route de Saint Laurent a Paul Isnard , entre le PK 70 y Citron au PK 118, Cremers 8149 ( P) ; La Fumée Oeste, Mori & Pipoly 15537 ( CR, NY, P) ; Fleuve Maroni, Pompidou-Papaichton, Sastre 6491 (P); aval Crique Roche, Tostain et al. 1769 (P).

Figures

FIGURE 1. Laxoplumeria aberrans (A–F from Mori et al. 20933, P, G–H from Cremers 8149, P). A. Branch with inflorescence. B. Pedicels and bracts. C. Sepal, adaxial view. D. Corolla. E.Anther. F. Gynoecium and nectary. G. Fruit. H. Seed.

FIGURE 6. Distribution map of Laxoplumeria species.