Australian Tropical Rainforest Plants - Online edition

Pilidiostigma papuanum (Lauterb.) A.J.Scott


Herb (herbaceous or woody, under 1 m tall)
Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Flowers [not vouchered]. © G. Sankowsky
Flowers [not vouchered]. © G. Sankowsky
Leaves and fruit [not vouchered]. © G. Sankowsky
Scale bar 10mm. © CSIRO
Cotyledon stage, hypogeal germination. © CSIRO
10th leaf stage. © CSIRO
Family

Scott, A.J. (1978) Kew Bulletin 33: 327.

Stem

Can grow into a small tree but usually flowers and fruits as a shrub about 1-3 m tall.

Leaves

Leaf blades about 13 x 4 cm. Two intramarginal veins visible on the leaf blade, the outer vein about 0.5-2 mm from the margin and the inner vein about 2-5 mm from the margin. Lateral veins inconspicuous. Petiole flat or channelled on the upper surface. Oil dots quite numerous, pale brown (?) in colour.

Flowers

Calyx glabrous. Petals ovate or almost orbicular, about 7-9 x 6-7 mm, marked by numerous oil glands. Staminal disk flat-topped, stamens in many concentric circles. Pollen white. Stigma terminal, slightly wider than the style.

Fruit

Fruits ovoid, about 25-30 x 15-20 mm, calyx lobes persistent at the apex. Seeds variable in size, about 20-22 x 5-6 mm. Testa +/- smooth but marked by numerous oil glands. Anatomy of the seed difficult to interpret. Cotyledons fused together, radicle +/- at right angles to the long axis of the larger cotyledon and completely envelops the smaller cotyledon.

Seedlings

Cataphylls about 1-3 pairs, produced before the first pair of true leaves. At the tenth leaf stage: leaf blade obovate to elliptic, apex obtuse or almost acute, base cuneate or attenuate, glabrous. Oil dots quite numerous, visible with a lens. Stipules very small and inconspicuous. Seed germination time 51 to 89 days.

Distribution and Ecology

Occurs in CYP and NEQ. Altitudinal range from near sea level to 1100 m. Grows as an understory plant in well developed undisturbed lowland, upland and mountain rain forest. Also occurs in New Guinea.

Synonyms
Decaspermum papuanum Lauterb., Nova Guinea 8: 319(1910), Type: New Guinea, 6 Dec. 1907, Branderhorst 270; Holo: WRSL; Iso: K. Jambosa papuanum (Lauterb.) Diels, Beitrage zur Flora von Papuasien 8: 384(1922). Pilidiostigma recurvum (C.T.White) A.J.Scott, Kew Bulletin 33: 326(1978). Rhodomyrtus recurva C.T.White, Proceedings of the Royal Society of Queensland 47: 63(1936), Type: Queensland, Mossman River Gorge, 2 Feb 1932, L. J. Brass 2127; holo: BRI. Eugenia brassii Merr. & L.M.Perry, Journal of the Arnold Arboretum 23: 247(1942), Type: Papua, Tarara, Wassi Kussa River, Brass 8429; holo: A, iso: K, L.
RFK Code
3147
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