Bidens uapensis (F. Brown) Sherff, Publ. Field Mus. Nat. Hist., Bot. Ser. 16: 115. 1937.

Wagner, Warren L., Clark, John R. & Lorence, David H., 2014, Revision of endemic Marquesas Islands Bidens (Asteraceae, Coreopsideae), PhytoKeys 38, pp. 37-67 : 47-48

3. Bidens uapensis (F. Brown) Sherff, Publ. Field Mus. Nat. Hist., Bot. Ser. 16: 115. 1937. Figure 4

Campylotheca uapensis F. Brown, Bernice P. Bishop Mus. Bull. 130: 358. 1935.

Type.

Marquesas Islands. Ua Pou: Mt. Tekahoipu, 810 m, 9 September 1922, E.H. Quayle 1149 (lectotype, designated by Sherff, Publ. Field Mus. Nat. Hist., Bot. Ser. 16: 115. 1937: BISH-723226!). An additional syntype is Quayle 1066 (BISH).

Description.

Erect, suffrutescent perennial herbs 0.6-3 m tall. Leaves simple, 4.5-12 cm long including petiole, blades lanceolate to lanceolate-elliptic, 3-8.5 × 1-4 cm, mostly glabrous, except for a tuft of hairs on lower surface at base, margins serrulate to serrate, apex acuminate to occasionally acute. Heads 3-12(-16), in diffuse cymes, terminating main stem and lateral branches, 2-8 mm in diameter excluding rays, peduncles 0.4-7 cm long, stout; outer involucral bracts 1.5-8 mm long, well differentiated from inner bracts, margins ciliate, inner bracts often with a tuft of hairs at apex; ray florets 5-11 per head, sterile, rays yellow, 7-15 × 1.5-5 mm; disk florets ca. 23-25, perfect. Achenes gray or black, straight, 3-5 × 0.5 mm, tipped, margin setose; pappus of 2 irregularly antrorse barbed awns.

Distribution.

Marquesas Islands, endemic to Ua Pou, 6-920 m.

Habitat.

Ridges and slopes in openings of mesic or wet forest, with common species such as Metrosideros collina , Weinmannia marquesana , Freycinetia impavida, Hibiscus tiliaceus, Pandanus tectorius , and Dicranopteris linearis .

Conservation status.

IUCN Red List Category Endangered (EN), criteria B2a, B2b i-iii): B2, total area of occupancy less than 500 km² (c. 50 km²); B2a, fragmented populations; b (i-iii), habitat continuing decline inferred. The suitable habitat for Bidens uapensis on Ua Pou (c. 105 km²) is indicated as an endangered environment, threatened by human activity (deforestation, fire), feral animals, and invasive plants, thus reducing the extent of the forest. Nevertheless, Bidens uapensis has been observed to be locally common in some areas with good regeneration (Butaud, pers. comm. 2014), and consequently an alternative category might be Least Concern (LC).

Specimens examined.

Marquesas Islands. Ua Pou: Poumaka (above Hakahetau), SE facing near the base, 675 m, 9°23"38'S/140°4"53'W, 30 Nov 2003, Dunn 318 (BISH, K, MO, NY, PAP, P, PTBG, US); Along road between Hakamaii village and Hakotu valley, 300 m, 9°24"13'S/140°6"52'W, 15 Jul 2003, Lorence, Dunn, Wood & Teikiehuupoo 9098 (BISH, P, PAP, PTBG[2], US) [used in molecular study, Funk et al.]; Teavaiteaki Pass, along road to Hohoi, between Hohoi and Pass, Moukatutai, 274 m, 2 Jul 1997, Perlman, Wood, Meyer, Kautai & Kohumoetini 15883 (BISH, MO, P, PAP, PTBG, UBC, US); Toua, growing alongside a newly cut road at the pass into Hakatau valley, 550 m, 9°26"4'S/140°3"50'W, 16 Jul 2003, Dunn, Lorence & Wood 241 (P, PAP, PTBG, US) [used in molecular study, Funk et al.]; Kuata’u Mountain, near Hakahou, 6 m, 9°21"24'S/140°3"24'W, 3 Jul 1997, Wood 6443 (BISH, MO, P, PAP, PTBG, UBC, US); Hakahau, Tehutu Road, 700 m, 10 Aug 1988, Gagné & Montgomery s.n. (BISH [2]); Teavahaakiti, steep slopes of main ridge to S of Oave, N & E facing cliffs between Teavahaakiti & Tekohepu, 869 m, 5 Jul 1997, Perlman & Wood 15912 (AD, MO, NY, P, PAP, PTBG, US); Teavahaakiti, cliffs between Tekohepu & Teavahaakiti, 686 m, 4 Jul 1997, Perlman, Wood & Kautai 15894 (AD, BISH, HAST, MO, NY, P, PAP, PTBG, UBC, US); Forested ridges and slopes to the north and west of Pouakei, 701 m, 9°23"S/140°5"W, 8-9 Jul 2004, Wood & Perlman 10839 (BISH, P, PAP, PTBG, US); Pouakei and along ridge trail to Pouakei, across valley from Pou Maka and Pou Maka trail, 808 m, 9°23"9.63'S/140°4"9.81'W, 9 Jul 2004, Perlman & Wood 19184 (PTBG, US); Ridge just north of Oave, between Oave and Matahenua, high mountain peaks along main backbone ridge, 945 m, 9°23"45.5'S/140°4"43.3'W, 3 Jul 2004, Perlman & Wood 19083 (BISH, NY, P, PAP, PTBG, US); Hakahai, valle de Hakaohoka, environs du sommet du Mt. Aefiti, 400 m, 9°22"S/140°4"W, Dec 1985, Ottino s.n. (PAP); 1500 m, 7 Sep 1922, Quayle 1066 (BISH); Central Ua Pou including the summit crest regions around Oave and the near-by peak of Matahenua, 899-924 m, 9°23"S/140°4"W, 2 Jul 2004, Wood & Perlman 10820 (PTBG).

Discussion.

Bidens uapensis can be differentiated from other species in having achenes that have pronounced barbed awns and leaf blades with a tuft of hairs on lower surface at the base, a character not seen in any of the other Marquesas Bidens .

Figures

Figure 4. Bidens uapensis (F. Brown) Sherff A Distal part of plant B Leaf surface (underside) C Head showing rays and disk florets D Head with ray florets removed to show involucral bracts E-F Ray florets, showing variation G-H Disk florets, showing variation. Drawn from Dunn 241 (US) [A-E, G], Perlman & Wood 19083 US [F, H].