Kadua lucei (Lorence & J.Florence) W.L.Wagner & Lorence, Syst. Bot. 30: 832 2005.

Wagner, Warren L. & Lorence, David H., 2011, Revision of Kadua (Rubiaceae) in the Marquesas Islands, French Polynesia, with description of the new species K. lichtlei, PhytoKeys 4, pp. 125-138 : 129-131

Kadua lucei (Lorence & J.Florence) W.L.Wagner & Lorence, Syst. Bot. 30: 832 2005.

Hedyotis lucei Lorence & J. Florence (Adansonia, sér. 3, 22: 225, 2000). [Basionym]

Type.

Marquesas Islands: Fatu Hiva: au pied de la crête à Touaouoho, env. 1000 m, 3 Aôut 1999, J.-P. Luce s.n. (Holotype P!)

Description.

Glabrous shrubs 1.5-2 m tall, leafy twigs 4-6 mm in diam., internodes compressed, bark brown, smooth to striate or rugulose. Leaves of a pair equal to subequal, blade elliptic to obovate-elliptic, (5.3 –)10– 14.5 × (3.3 –)7– 10 cm, discolorous, chartaceous to subcoriaceous, base acute to obtuse or rounded, apex acute to obtuse or rounded, often abruptly short acuminate, margin entire, weakly revolute; secondary veins 8-10 pairs, loosely brochidodromous, secondary veins prominulous on both surfaces, tertiary veins slightly prominulous below; petioles purple when fresh, 2 -4 × 2-5 mm, stout, adaxially flattened and slightly winged; stipules inter- and intrapetiolar, apex shortly cuspidate, sheath semicircular, 3 × 4-7 mm, fused with the adaxial petiole bases. Inflorescences (only seen with old flowers and young fruits) terminal, corymbiform cymose, 8-9 × 6 cm, peduncle 35 mm long, 2.5-3 mm in diameter, compressed, primary axis 2.5-3 cm × 2-2.5 mm with two pair of secondary branches, the lower pair often branching once again, the upper pair unbranched, the ultimate branches each bearing 2-3 flowers, lower bracts foliaceous, suborbicular, 15 mm in diam. Flowers glabrous, about 30 per inflorescence, bracts broadly triangular, scarious, 1 × 1.5 mm, pedicels stout, 2-3 × 0.5-1 mm; hypanthium obconical, 2-3 mm long, calyx limb cupuliform, 2-3 mm long, calyx lobes 4, broadly triangular, 0.5-0.7 × 1.5 mm; corolla fleshy, white when fresh, buds not seen, at anthesis salverform, tube purple tinged when fresh, 22-26 mm long, 1.7-2 mm wide medially, lobes 4, linear to oblong, recurved, 8-10 × 1.5-2 mm, apex with a hook-like appendage 0.5-1 mm long; flowers possibly dimorphic; stamens included, anthers linear, 3-3.5 × 0.3-0.4 mm, connective attached 2 mm from apex of tube; style included, 20 mm long, two stigmatic lobes linear, 2.5 mm long. Fruits on stout pedicels 5-7 mm long, capsules turbinate to obovoid-turbinate, old capsules 7-8 × 6 mm, consisting of network of persistent vascular bundles enclosing endocarp, apex (beak portion above the calyx) 1-1.5 mm long. Seeds not seen.

Distribution.

Marquesas Islands, Fatu Hiva where known only from a single small population on the summit ridge between Tekou and Touaouoho peaks.

Ecology.

This new species was collected at 915-1000 m elevation on a steep, precipitous ridge crest in wet shrubland with species of Alsophila , Freycinetia , and Histiopteris .

Etymology.

The specific epithet honors its discoverer and first collector, Mr. Jean-Pierre Luce, an amateur naturalist, in recognition of his efforts to explore the most rugged mountainous zones of the Marquesas and thus increase our knowledge of their flora and vegetation.

Conservation status.

The suitable habitat for Kadua lucei on Fatu Hiva (ca. 85 km2) is indicated as an endangered environment, threatened by feral animals and invasive plants, reducing the extent of the forest. Estimated population size is about 3-4 individuals. Following the criteria and categories of IUCN (2001) Kadua lucei is assigned a preliminary Red List status of Critically Endangered (CR): B2a, B2b ( i–iii); D: B2: total area of occupancy less than 10 km2 (ca. 5 km2). B2a, a single population known; b ( i–iii), habitat continuing decline inferred. D, population estimated to number fewer than 250 individuals.

Specimens examined.

Marquesas Islands: Fatu Hiva: sous la crête entre Tekou et Touaouoho, 915 m, 15 février 2000 (st), J.-Y. Meyer & J.-P. Luce 835 (PAP, PTBG).

Discussion.

This species is apparently related to Kadua tahuatensis from which it differs by its larger inflorescence reaching 8-9 cm long and 6 cm wide, more numerous flowers, about 30 per inflorescence, and larger white corollas with a longer purple-tinged tube 22-26 mm long. Although mature fruits of Kadua lucei are not known, old fruits are smaller than those of Kadua nukuhivensis and Kadua tahuatensis .