Planchonella ulfii Munzinger, 2015

Munzinger, Jérôme, 2015, Novitates neocaledonicae I: An additionnal new species of Planchonella (Sapotaceae) endemic to the Roches de la Ouaième, Phytotaxa 201 (1), pp. 71-78 : 72-74

Planchonella ulfii Munzinger , sp. nov. ( Figs. 1 , 2 & 3 )

Haec species Planchonellae roseolobae Munzinger & Svenson similis, sed longidecurrenti imo, revoluta margine, numerosis intersecondariis nervis reticulo, minoribus crassioribusque foliis, differt.

Type :— New Caledonia, North Province, sommet des roches de la Ouaième, 900 m, 4.XI.2010, fl., Munzinger, Hequet, Vandrot, Butin, Birnbaum & Rounds 6150 ( P 00641006 ! - holotype; isotypes: NOU 034143 !, S!) .

Small branched shrub, reaching 2.5 m tall, with erect branches, young twigs ferruginous with +/- persistent indument, old twigs brown-black. Leaves thick, dark green and shiny above, light green below (in fresh material), clustered toward the summit of twigs, blade obovate, 4–10 × 2–4 cm, with sparse trichomes when young, then quickly glabrous, petiole 15–33 mm long, 1.5 mm in diam., puberulent when young then glabrous, base long decurrent on petiole, margin flat or revolute in fresh material, revolute when dry, apex rounded, venation brochidodromous, extending very close to the margin (less than 1 mm), midvein prominent below, flat to sometime canaliculate above, 6 to 10 pairs of secondary veins, distinct, intersecondary veins numerous, tertiary venation distinct, reticulate. Flowers 5-merous, hermaphroditic or female, borne axillary to the leaves and on the twigs just below the oldest leaves, oriented more or less toward the ground; pedicel curved downward, 2–3(–4) mm, pubescent. Sepals widely elliptic, 3–4 mm, ferruginous, the outer ones completely covered with indument on the adaxial face, the inner ones larger, lacking indument towards the membranous and ciliate margins. Corolla 4–4.5 mm long and wide in hermaphrodite flowers, 3.5 mm long and 2.5 mm wide in female flowers; tube 3 mm long, white or cream, lobes white or slightly pinkish, 1–1.25 mm long, ± oblong. Stamens shorter than the corolla, yellow, filaments ~ 1 mm long, anthers ~ 1 mm long, staminodes triangular, as long as filaments. Ovary cylindrical, hairy, 1.5 mm high, 2 mm in diam., slightly lobed, style thick, 2 mm long, slightly shorter than the corolla. Fruit (immature) obovoid, ridged, apex acuminate, up to 33 × 15 mm (acumen ca. 5 mm), glabrous except few hairs at the base. Seeds unknown.

Distribution and Ecology: — Planchonella ulfii is only known from a single locality in the north-eastern part of New Caledonia’s main island (Grande Terre) situated on the summit crest of the Roches de la Ouaième (Wayem), above 900 m ( Fig. 3 ), where a population of 10 individuals was observed. The second summit of the Roches de la Ouaième, which also reaches to 900 m and is located slightly to the east (see Fig. 3 ), could not be explored.

Phenology: —Flowers have been observed in November and February, with nearly ripe fruits seen in February.

Etymology:—This new species is dedicated to my friend and colleague Ulf Swenson who has greatly contributed to systematics of New Caledonian Sapotaceae during the last decade with his revisions of Pichonia ( Swenson & Munzinger 2012) Pycnandra Bentham (in Bentham & Hooker 1876: 658) subg. Pycnandra ( Swenson & Munzinger 2009) , P. subg. Trouettia (Pierre ex Baillon) Swenson & Munzinger (2010c: 337) , P. subg. Achradotypus (Baillon) Swenson & Munzinger (2010a: 188) and P. subg. Sebertia (Pierre ex Engler) Swenson & Munzinger (2010b: 242) , in addition to the papers on Planchonella cited above and several studies on the phylogenetics of these plants.

Discussion:— Planchonella ulfii belongs to clade D1 as defined by Swenson et al. (2007b; 2014), a placement that is consistent with its ridged fruit ( Fig. 2C, D ). The plant resembles P. roseoloba Munzinger & Swenson in its morphology, but differs in its smaller and thicker leaves with revolute margin, reticulate venation, numerous intersecondary veins and long-decurrent base (in herb. and see Fig. 2C ). These two species also differ in their habit and ecology: P. ulfii is a shrub restricted to the summit of the Roches de la Ouaième, above 900 m, in low shrubby vegetation, whereas P. roseoloba is a tree occurring in dense humid forest at 300–700 m elevation.

Some flowers of Planchonella ulfii appear morphologically to be hermaphrodite whereas others are female (with staminodes rather than fertile stamens), a situation suggesting that the species may be gynomonoecious, as observed in several other new Caledonian members of the genus ( Méndez & Munzinger 2010).

Conservation status: —With a single known population of 10 individuals confined to forest situated along a crest that is subject to anthropogenic fires that are regularly set from the base of the cliffs, Planchonella ulfii is here assigned a preliminary conservation status of Critically Endangered (CR, D1) using the IUCN Red List criteria ( IUCN 2012).

Additional specimens examined (Paratypes): — New Caledonia, North Province, sommet des roches de la Ouaième, 3.II.2013 (fl., fr.), Munzinger, Swenson, Isnard & Butin 7095 (BRI!, MO!, MPU!, NOU!, P!, S!).

Figures

FIGURE 1. A. Floral bud. B. Flowering twig. C. Gynoecium. D. Leaf. E. Inside of the corolla with stamens and staminodes. F. Dorsal face of external sepal. G. Dorsal face of internal sepal. (A–G based on Munzinger & al. 6150).

FIGURE 2. Photos of Planchonella ulfii taken in the field. A. Habit with leaves clustered toward the summit of twigs. B. Flower. C. Glabrous leaves, intersecondary veins visible, young fruit in the lower left. D. Nearly ripe ridged fruit. (A–D from Munzinger & al. 7095, photos J. Munzinger).

FIGURE 3. Distribution of Planchonella ulfii. Grey represents ultramafic substrates, dotted lines delineate protected areas, dashed lines show the 500 m elevational contour, and continuous lines the 900 m contour.