Weinmannia marquesana F. Br. angustifolia Lorence & W. L. Wagner, 2011

Lorence, David H. & Wagner, Warren L., 2011, Weinmannia marquesana var. angustifolia (Cunoniaceae), a new variety from the Marquesas Islands, PhytoKeys 4, pp. 61-66 : 62-65

Weinmannia marquesana F. Br. angustifolia Lorence & W. L. Wagner var. nov. Figs 1 2

Latin.

Ab Weinmannia marquesana var. marquesana atque W. marquesana var. myrisnites foliis unifoliatis anguste ellipticis vel oblongo-ellipticis 2.5-5.8 × 0.4-1.2 cm differt.

Type.

Marquesas Islands: Tahuata: Ridge between Amatea & Haaoiputeomo, summit crest of island, 914 m elevation, 12 July 1997 [fl, fruit], S. P. Perlman, K. R. Wood, and J.-P. Luce 15992 (holotype: US!; isotypes: BISH!, MO!, P!, PAP!, PTBG!).

Description.

Shrub or small tree 2-3 m tall, leafy twigs 0.8-1 mm in diam., terete, sparsely strigose with pale brown hairs when young, glabrate, reddish brown and lenticellate when fresh. Leaves opposite, unifoliate, blade narrowly elliptic to oblong elliptic, 2.5-5.8 × 0.4-1.2 cm, costa strigulose on both surfaces, glabrescent above; secondary veins 8-10 pairs, red or yellow when fresh, visible above, higher order venation reticulate, prominulous and visible to tertiary beneath, margins finely serrate, thickened, with 8-14 teeth on each side; petioles 1.5-8 × 0.7-0.8 mm, narrowly winged, strigulose, red when fresh; stipules rounded, 0.3-0.7 mm long, apex obtuse, strigulose, thick, persistent. Inflorescences 3.5-5.5 × 2-5 cm, usually trichotomous and consisting of 3(5) racemes, se ssile or on slender peduncle 10-15 mm, the axes strigulose, red when fresh, each raceme with 25-40 flowers; bracteoles reduced or absent; flowers on pedicels 0.8-1.7 mm long, calyx lobes 0.6-0.9 × 0.5-0.6 mm, broadly ovate, obtuse, sparsely strigulose or glabrous without, deciduous in fruit; petals broadly ovate, 1-1.4 × 0.7-0.9 mm, apex obtuse; male flowers with stamens twice as long as pistil, filaments 2-2.5 mm, anthers ovoid, 0.4 mm, ovary 0.6-0.7 mm, style 0.2 mm, stigma bilobed and slightly thickened; female flowers with stamens subequal to pistil, filaments 1-1.2 mm, anthers ovoid, 0.2 mm, abortive, ovary 1 mm, strigulose, styles 2, 0.6-0.8 mm, stigma bilobed, papillose, and slightly thickened. Infructescence 5-7 × 5.5-6.5 cm; capsules narrowly obovoid, 4-5 × 1.5-2 mm (excluding the styles), strigulose, the persistent styles 1 mm. Seeds narrowly oblong- ellipsoid, c. 0.8-1 mm, comose with tuft of hairs 0.3-0.4 mm at each end.

Distribution.

Known only from the summit ridge of Tahuata, Marquesas Islands.

Ecology.

This new variety occurs in windswept native wet evergreen shrubland or low wet forest on ridge crests from 620 to 850 m elevation, with Crossostylis biflora J. R. Forst. & G. Forst., Freycinetia arborea Gaudich., Metrosideros collina (J. R. Forst. & G. Forst.) A. Gray, Polyscias marchionensis (F. Br.) Lowry & G. M. Plunkett, tree ferns including Alsophila tahitensis Brack., and numerous pteridophytes and bryophytes in the understory. Collected in flower in July and September and in fruit in July.

Conservation status:

Exact size of the population unknown, although this variety is said by collectors to be "locally common" or "abundant" (four collections made at 750 to 850 m elevation) or "somewhat rare" (one collection made at 620 m elevation). However, Weinmannia marquesana var. angustifolia is known only from a single locality on a single island with a total area of occupancy of less than ca. 5km2. The suitable habitat on Tahuata (ca. 61 km2) is indicated as an endangered environment, threatened by human activity (deforestation and fire), feral animals, and invasive plants, reducing the extent of the forest.We recommend placing this variety in the IUCN Endangered (EN) category B2a, B2b ( i–iii): B2 total area of occupancy less than 500 km2; B2a, a single population known; B2b ( i–iii), continuing habitat decline inferred.

Specimens examined.

Marquesas Islands: Tahuata: Ha'aoiputeomo: near the summit of Amatea on north facing ridge 850 m elevation, 9°56'36" S, 139°5'5" W, 3 Jul 2003, L. M. Dunn 198 (P, PAP, PTBG, US); Haaoiputeomo, summit ridge and highest peak on the island, 927 m, 12 July 1997, S. P. Perlman, K. R. Wood 15964 (BISH, MO, P, PAP, PTBG, US). Amatea, W of antenna, S facing slope over Hanatetena, 793 m, 13 July 1997, S. P. Perlman, K. R. Wood, J.-P. Luce 15982 (MO, PAP, PTBG, US). Ridge between Amatea & Haaoiputeomo, summit crest of island, 823 m, 12 July 1997, S. P. Perlman, K. R. Wood, J.-P. Luce 15983 (MO, NY, PAP, PTBG, US). Trail from Amatea to Moteve, above Haaoipu Bay, to NE of Hanatetena, top of ridge crest, W facing slope, 808 m, 17 July 1997, S. P. Perlman, K. R. Wood, J.-P. Luce 15995 (AD, MO, NY, P, PAP, PTBG, US). Summit of ridge above Vaitahu, near Haaoiputeomo, on ridge near antenna, along ridge crest between Vaitahu & Hanatetena, 835 m elevation, 1 September 1995, S. P. Perlman, K. R. Wood, J. P. Luce 14911 (BISH, MO, P, PAP, PTBG, US). Summit of ridge above Vaitahu, near Haaoiputeomo, on ridge near antenna, along ridge crest between Vaitahu & Hanatetena, 823 m, 1 September 1995, S. P. Perlman, K. R. Wood, J.-P. Luce 14918 (BISH, MO, P, PAP, PTBG, US). Tahuata: Vaitahu, crête d'Amatea, début de la montée raide vers la partie haute, 620 m, 10 April 1975, P. A. Schäfer 5499 (BISH, K, PTBG, US). De Hamatea (750 m) à la crête centrale de l'île, 750-850 m, 26 May 1975, J.-C. Thibault 60 (BISH, PAP, PTBG, US). Haaoiputeoma, near satelite dish, NE from Vaitahu to summit ridge; wind swept ridge, 610-762 m, 1-2 September 1995, K. R. Wood 4431 (BISH, MO, P, PAP, PTBG, US). Haaoiputeoma, near satelite dish, NE from Vaitahu to summit ridge; along wind swept rim, 610-762 m, 1-2 September 1995, K. R. Wood 4438 (AD, BISH, MO, P, PAP, PTBG, US).