Cyrtandra uahukaensis W. L. Wagner & Lorence, 2013

Wagner, Warren L., Wagner, Anthony J. & Lorence, David H., 2013, Revision of Cyrtandra (Gesneriaceae) in the Marquesas Islands, PhytoKeys 30, pp. 33-64 : 42-43

4. Cyrtandra uahukaensis W. L. Wagner & Lorence sp. nov. Fig. 6

Type.

Marquesas Islands: Ua Huka: Summit of ridge near Hitikau, Hibiscus tiliaceus forest, 820 m, 28 June 1997, S. Perlman, K. Wood, & J.-Y. Meyer 15844 (holotype: PTBG-026355!; isotype: US!).

Description.

Shrubs 1-2 m tall; stems apparently few. Leaves opposite, borne on upper 2-5 nodes, broadly elliptic, 18-26 × 7-10 cm, lower surface densely ferruginous appressed pubescent, upper surface glabrate, irregularly dentate, the teeth variable in size, petiole 5-6.5 cm, ferruginous appressed to spreading pubescent. Flowers in cymes arising in the upper leaf axils, apparently 1-3 flowered, peduncle 0-2 mm, ca. 1-2 mm in diameter, pedicels up to 6 mm; calyx cylindrical-ellipsoid, white, plicate; corolla much longer than calyx; style up to 10 mm, flower parts otherwise unknown. Partly mature berries up to 14 mm long.

Distribution.

Marquesas Islands, rare, endemic to Hitikau summit area, Ua Huka, from 820-870 m.

Ecology.

Cyrtandra uahukaensis is known only from Freycinetia impavida - Hibiscus tiliaceus shrubland.

Etymology.

The specific epithet refers to the island of Ua Huka where the only known populations occur.

Conservation status.

IUCN Red List Category: Critically Endangered CR B2a + 2b (i, ii, iii). B2: total area of occupancy less than 10 km2 (ca. 5 km2). B2a, a single population known; b (i-iii), habitat continuing decline inferred. The suitable habitat for Cyrtandra uahukaensis on Ua Huka (ca. 83 km2) is indicated as an endangered environment, threatened feral animals, and invasive plants, reducing the extent of the forest ( Florence and Lorence 1997; Mueller-Dombois and Fosberg 1998; Meyer and Salvat 2009).

Specimens examined.

Marquesas Islands. Ua Huka: 13 May 1918, Henry 7 (P); Hitikau summit region, large bowl-like plateau, 823-884 m, 8°54'22"S, 139°31'66"W, 28 June 1997, Wood 6380 (PTBG); Hitikau and the Vaikivi summit region, 790 m, 8°54'S, 139°31'W, 14-15 June 2004, Wood & Perlman 10756 (PTBG).

Discussion.

Little is known about this species as it has been collected only four times. None of the collections were preserved with any flowers, only young fruit. Cyrtandra uahukaensis is characterized by the densely pubescent leaves and condensed inflorescences. It grows in the same area as Cyrtandra jonesii and appears to be closely related. Their relationships and ecology should be studied as it seems atypical for two very closely related species of the genus to grow in near sympatry.

Figures

Figure 6. Cyrtandra uahukaensis W. L. Wagner & Lorence (Perlman et al. 15844, isotype US).