Bidens bipontina Sherff, Bot. Gaz. (Crawfordsville) 85: 10. 1928.

Wagner, Warren L., Clark, John R. & Lorence, David H., 2014, Revision of endemic Marquesas Islands Bidens (Asteraceae, Coreopsideae), PhytoKeys 38, pp. 37-67 : 53-54

8. Bidens bipontina Sherff, Bot. Gaz. (Crawfordsville) 85: 10. 1928. Figure 2A-C

Bidens serrulata Sch. Bip., Flora 39: 361. 1856, non (Poir.) Desf. 1815.

Coreopsis serrulata (Sch. Bip.) Drake, Ill. Fl. Ins. Mar. Pac.: 210. 1890, non Poiret 1811.

Campylotheca serrulata (Sch. Bip.) F. Br., Bernice P. Bishop Mus. Bull. 130: 356. 1935.

Type.

Marquesas Islands. Nuku Hiva, D.E.S.A. Jardin 132 (holotype: P).

Description.

Erect, suffrutescent perennial herbs 1-1.3 m tall. Leaves membranous, simple or compound and trifoliolate, 4.3-15 cm long including petiole, blades elliptic-lanceolate to narrowly elliptic, 3-10.5 × 1-3 cm, glabrous, margins serrate, apex long-acuminate to caudate. Heads 6-15, often with two or three heads in tight clusters, in cymes terminating main stem and lateral branches, 2-5 mm in diameter excluding rays, peduncles 2-25 mm long, glabrous; outer involucral bracts ca. 5 mm long, linear, well differentiated from inner bracts, glabrous; ray florets usually 7-9 per head, sterile, rays yellow, 13-20 × 3-4 mm, apex often minutely bi- or tri-lobed or rounded; disk florets ca. 30-32, perfect. Achenes black, 6-7 mm long, margin setose; pappus usually of 2 minute awns.

Distribution.

Marquesas Islands, Nuku Hiva, endemic to the Toovii Plateau area, especially Tapueahu Valley, 500-1165 m.

Habitat.

Bidens bipontina is known only in montane wet shrubland with Freycinetia impavida and Hibiscus tiliaceus dominant.

Conservation status.

Proposed IUCN Red List Category Endangered (EN), criteria B2b i-iii): B2, total area of occupancy less than 500 km² (ca. 50 km²); b (i-iii), habitat continuing decline inferred. The suitable habitat for Bidens bipontina on Nuku Huka (ca. 340 km²) is indicated as an endangered environment, threatened by human activity (deforestation), feral animals, and invasive plants, thus reducing the extent of the suitable habitat.

Specimens examined.

Marquesas Islands. Nuku Hiva: Terre Deserte, crête W du Mt. Akaupe, 1165 m, 8°52"S/140°10"W, 10 Aug 1987, Florence 8539 (BISH [2]); Route plateau de Toovii-Terre Deserte, 2 km après le col, 930 m, 8°52"S/140°9"W, 9 Dec 1982, Florence 4348 (BISH, P, PAP, US); Toovii, Ooumu area, top of Tapueahu Valley off new hwy, 1067-1128 m, 8°51"S/140°19"W, 20-22 Sep 1995, Wood & Perlman 4601, (BISH, P, PAP, PTBG, UBC, US); Along old Airport road, across summit crest from Toovii, back drainages of Tapueahu Valley, 1085 m, 21 Sep 1995, Perlman & Wood 15028 (AD, BISH, F, MO, P, PAP, PTBG, US); Ridge crest 2 valleys S of Airport road, back of Tapueahu gulch, to NW of Toovii over summit crest, 1024 m, 21 Sep 1995, Perlman & Wood 15021 (AD, BISH, MO, P, PAP, PTBG) [apparently mixed collection with US sheet, a hybrid]; 500 m, 15 Oct 1922, Quayle 1235 (BISH).

Discussion.

Bidens bipontina is distinctive in its conspicuously caudate leaves and erect linear involucral bracts.

Figures

Figure 2. Bidens bipontina Sherff (A-C). A Distal part of plant B Head post-flowering showing involucral bracts and apex of achenes C Head showing rays and apex of disk florets. Drawn from Perlman & Wood 15028 (US), except B from Wood and Perlman 4601 (US). Images used to augment illustration from field shots of Wood and Perlman 4601 and Perlman and Wood 15021. Bidens henryi Sherff (D-F). D Distal part of plant E Head post-flowering showing involucral bracts F Head showing rays and disk florets. Drawn Wood 10038 (US), except F from Perlman 14868 (US). Images from field shots used to augment illustration of Wood 10038, Wagner 6219 and Lorence & Price 8932.