Australian Tropical Rainforest Plants - Online edition

Gynochthodes retropila (Halford & A.J.Ford) Razafim. & B.Bremer


Slender Vine
Click/tap on images to enlarge
Fruit, side views and transverse section. © W. T. Cooper
Scale bar 10mm. © CSIRO
10th leaf stage. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
Family

Razafimandimbison, S.G. & Bremer, B. (2011) Adansonia 33(2): 294

Stem

A slender, wiry vine to 5 mm stem diameter. New growth pale green, slightly resinous. Young branchlets rounded, moderately to densely hairy becoming glabrous, hairs retrorse.

Leaves

Leaves opposite. Stipules interpetiolar, sheathing, 1/7-3 mm long. Leaf blades thin, narrow elliptic or narrow ovate, 4.5-10 x 1.5-4 cm, petioles about 4-10 mm long. Lateral veins 4-8, forming loops inside the blade margin, midvein raised on upper surface.

Flowers

Inflorescence 2 or 3 flowered umbell-like cymes; cymes shortly pedunculate. Flowers shortly pedicellate, 3-5 (mostly 4) merous, bisexual or possibly unisexual on separate plants. Calyx tube 0.5-0.8 long x 1.5.-1.7 mm wide. Corolla tube 2.9-3 mm long, lobes 2-2.6 mm x 1.5-2.2 mm long and recurved. Stamens inserted inside throat of corolla tube. Bisexual flowers with styles 3.6-4.6 mm long, exserted from corolla tube, stigma bifid 0.5-1.4 mm long, more or less erect. Unisexual flowers with style absent, stigma bifid 0.3-0.6 mm long, erect.

Fruit

Fruits ca. 5-10 x 4.5-9 mm, orange when ripe, glabrous. Seeds elliptic, about 2.4-3 mm long, 3-sided or shaped like a segment of an orange. Embryo about 1 mm long. Radicle straight, longer than the +/- orbicular cotyledons.

Seedlings

Cotyledons broadly ovate to +/- orbicular, about 7-9 x 6-9 mm. First pair of true leaves with undulate margins. At the tenth leaf stage: stems clothed in short retrorse, i.e. backward-pointing, hairs which feel rough when the fingers are run up the stem. Stems twining. Leaf blade about 3-4 x 1-1.5 cm. Veins forming loops inside the blade margin. Stipules interpetiolar, completely encircling the stem with a sheath about 1.5 mm long. Seed germination time 75 to 114 days.

Distribution and Ecology

Endemic to NEQ. Known to occur from the Danbulla area on the Lamb Range to the Tully Falls area, with disjunct populations near Cape Tribulation and the eastern foothills of Mt Bartle Frere. Altitudinal range from 600-1100 m. Grows in wetter simple to complex notophyll vine forest or complex mesophyll vine forest.

Synonyms

Morinda retropila Halford & A.J.Ford, Austrobaileya 8(1): 85 (2009). Type: Queensland. Cook District: Wooroonooran National Park, start of Bartle Frere walking track, 27 November 2001, P.I. Forster PIF27757 & A.M. Young. Rubiaceae Gen. Nov. sp. Boonjee (LJW+ 6837A) .

RFK Code
2506
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