Hibiscus propulsator Craven & B.E. Pfeil

Craven, Lyndley A. & Pfeil, Bernard E., 2004, Australian representatives of Macrostelia transferred to Hibiscus (Malvaceae), with the description of a new species, Adansonia (3) 26 (2), pp. 235-240 : 238

2. Hibiscus propulsator Craven & B.E. Pfeil , sp. nov.

A H. macilwraithensi (Fryxell) Craven & B.E. Pfeil segmentis epicalycis linearibus usque lineariellipticis et corolla rubra, et H. tozerensi Craven & B.E. Pfeil epicalyce 7-9-segmentatis et ad basim divisis et corolla effusa rubraque differt.

TYPUS. — Australia: Queensland, Temple Bay, c. 2 km NW of Bolt Head, 12°15’S, 142°04’E, 12 July 1991, Forster 8937 (holo-, BRI; iso-, A, B, BISH, BO, CANB, G, K, L, LAE, MEL, P, QRS) .

Shrub to 3 m tall, multistemmed from below ground level; branchlets densely stellate-hairy, the internodes 0.3-2.5 cm long; stipules filiform, deciduous, 0.25-1.2 cm long. Leaves alternate, 4.5-28 cm long, 1.5-9 cm wide; lamina narrowly obovate to narrowly subpanduriform, the base rounded to cordate, the apex acuminate to rounded, the margin distantly serrate (often obscurely so), the venation pinnate with 6-10 primary veins on each side of the midrib, weakly discolorous, the abaxial and adaxial surface sparsely and minutely stellate-hairy (excepting the midrib which is more densely stellate-hairy than the remainder of the surface) with the hairs predominantly or exclusively inserted on the midrib and veins; petiole 0.2-0.5 cm long, stellate-hairy. Flowers 1- 2(-3) per leaf axil; peduncle and pedicel combined 0.6-2.8 cm long, the articulation about one-third to half-way from the peduncle base, stellate-hairy; epicalyx segments 7-9, linear to linear-elliptic, 0.7-1.2 cm long, free to the base, stellate-hairy; calyx narrowly ovoid, valvate, 5- lobed (2 or 3 lobes sometimes tardily separating from the adjacent lobe), 1-2 cm long, the lobes 0.3-0.6 cm long, stellate-hairy; petals 5, imbricate, adnate to the ovary/staminal column for c. 0.3 cm but otherwise free, spathulate with the apex obliquely truncate, 2.2-3.7 cm long, deep rose pink, wine-red or red, stellate-hairy on the abaxial surface; staminal column 2.4-3.2 cm long, white, 5-toothed at the apex, stellate-hairy proximally and glandular-hairy for the remainder (especially so on the apical teeth); stamens 20, in a whorl of 10 pairs (the stamens of each pair superposed), the whorl 0.2-0.3 cm below the apex of the staminal column, the filaments spreadingascending, 0.3-0.6 cm long, white; style branches 5, erect and appressed to each other at anthesis and later separating, elongating and recurving, 0.3- 0.8 cm long, very pale pink, the stigmas capitate, hairy; ovary conical, 0.5 cm long, stellate-hairy, 5-loculate with c. 6 ovules per locule. Fruit not seen. — Figs 1B; 2.

DISTRIBUTION AND ECOLOGY. — Hibiscus propulsator occurs on the eastern side of Cape York Peninsula in the Olive River-Bolt Head region ; recorded mainly in open forest (of Neofabricia , Thryptomene and Xanthostemon with emergent Araucaria cunninghamii ), low closed forest, in semideciduous vine thicket, evergreen vine forest, and rainforest; recorded substrates are reddish sandy soil, and white sand; recorded landscapes are sand dunes, and a creekline in a narrow gorge.

ETYMOLOGY. — The specific epithet is derived from the Latin propellere, propel, in reference to the propeller-like form of the petals. The red, propeller-like petals immediately distinguish this species from H. macilwraithensis and H. tozerensis , which appear to be its closest relatives.

SPECIMENS EXAMINED. — AUSTRALIA: Webb & Tracey 13532, Queensland: N of Olive River mouth, 12°07’S, 143°05’E (BRI); Webb & Tracey 13531, between Stoney Point and Mosquito Point, 12°25’S, 143°16’E (BRI); Clarkson & Neldner 8808, Temple Bay , 0-1 km W of Bolt Head, 12°15’S, 143°05’E (CANB, DNA, K, L, MBA, MEL, NY, PERTH, QRS); Forster 19355, same locality (BRI, MEL); Gray 6853, same locality (CANB, QRS); Gray 6856, same locality (CANB, QRS); Gray 6889, same locality (QRS); Sankowsky & Sankowsky 1144, same locality (BRI).