Heliotropium perlmanii Lorence & W. L. Wagner, 2015

Lorence, David H. & Wagner, Warren L., 2015, Heliotropium (Boraginaceae) in the Marquesas Islands (French Polynesia) with description of a new species, PhytoKeys 47, pp. 49-57 : 51-52

Heliotropium perlmanii Lorence & W. L. Wagner sp. nov.

Type.

Marquesas Islands. Eiao, north side of large valley which is south of Vaittuha Valley, Opituha Valley. Sea cliffs, with Heliotropium, Dodonaea, Cordia lutea. Shrubs 1-2 ft. tall; flower; leaves smaller than Nuku Hiva plants; not silvery, 1050 ft [320 m], 7 Jul 1988, S. Perlman & J. Florence 10052 (Holotype PTBG 009229; Isotypes BISH, F, MO, P, PAP, US). Figure 1.

Description.

Shrubs 30-60 cm tall, stems decumbent, virgately branched, with two subequal lateral branches developing adjacent to inflorescence; leafy stems 0.8-1.5 mm in diam., terete, brown, moderately shortly strigillose-canescent with white ascendant trichomes 0.1-0.2 mm long; older stems with peeling brown bark. Leaves opposite, blade elliptic to broadly elliptic or obovate-elliptic, 0.8-1.8 × 0.3-1.0 cm, apex obtuse to rounded, or occasionally truncate, usually apiculate, base acutely cuneate, sides slightly attenuate and decurrent, subcoriaceous to coriaceous and brown when dry, bright green when fresh, both surfaces moderately shortly strigillose with appressed trichomes 0.1-0.2 mm, pustular, venation obscure, 1-2 (-3) pairs secondary veins arising near base, petiole 2-4 mm long, 0.4-0.5 mm in diam., shortly strigillose. Inflorescences terminal, scorpioid-cymose, forked 1(-2) times, axes densely shortly strigillose-canescent like the stems, 2-4 cm long, peduncle 0.5-0.8 cm long, primary axes 1.5-3 cm long. Flowers sessile to subsessile, 18-23 per axis, calyx lobes 5, unequal, 1-2 larger, ovate, 1-1.5 × 0.6-1 mm, 3-4 smaller, narrowly ovate to oblong, 1 × 0.3-0.4 mm, densely strigillose toward base, corolla shortly funnelform, 2 mm long, tube 1-1.5 mm long, externally densely villose-strigillose, internally slightly villosulous in throat, lobes 5, subcircular, 0.5-0.7 × 0.5-0.7 mm, margin crisped, stamens 5, attached midway in tube, basifixed, anthers ellipsoid, 0.5-0.6 mm long, apiculate; ovary cylindric-ovoid, glabrous except for ring of trichomes 0.2-0.3 mm long surrounding base of style, style terminal, 0.3 mm long, stigmatic column 0.3-0.4 mm long, cylindrical-conical, apex strigillose, base annular. Fruit broadly ovoid, 1 × 1.6 mm, shortly strigillose, shallowly 4-lobed, dry, splitting into 4 wedge-shaped nutlets. Nutlets 1.3-1.5 × 1-1.1 mm, dorsally strigillose, ventrally glabrous, brown.

Distribution.

Marquesas Islands, known only from three collections made on Eiao.

Habitat.

Grows on windward sea cliffs, with Dodonaea viscosa Jacq., Cordia lutea Lam., and Bidens beckiana (F. Br.) Sherff.

Conservation status.

Endangered (EN): B1ab (i, ii, iii) + 2ab (i, ii, iii): B2: total area of occupancy less than 500 km² (ca. 47 km²). B1a, severely fragmented; B1b (1-iii), habitat quality continuing decline inferred. The suitable habitat for Heliotropium perlmanii on Eiao (40 km²) is indicated as an endangered environment, threatened by feral animals and invasive plants, thus reducing the extent of the suitable habitat. Eiao has populations of feral sheep, pigs, cats, and rats (J.-F. Butaud, pers. comm. 2013).

Etymology.

We are pleased to name this new species in recognition of rough-terrain botanist Steven P. Perlman (National Tropical Botanical Garden) in recognition of his contributions to our knowledge of the flora of the Pacific region. Steve collected the type specimen and in his label data noted several differences from Heliotropium marchionicum .

Discussion.

Collections of this species were previously distributed as Heliotropium marchionicum , which differs by its non-virgate sympodial branching, more densely strigillose indument, larger leaves, and flowers about twice as large with corollas 2.6-3.2 mm long.

Specimens examined.

Marquesas Islands. Eiao: 20 September 1922, R.H. Beck & W.B. Jones 1537 (A, BISH); NW side of island, Vaituha Bay and summit ridge of island 400 m elevation, 1 August 1977, B.H. Gagné 1295 (BISH).