PNGTrees – Rhizophora stylosa Griff.

 

Barry Conn (NSW) & Kipiro Damas (LAE).
Copyright held by the authors, Royal Botanic Gardens and Domain Trust, and Papua New Guinea National Herbarium

Rhizophora stylosa Griff.

Notulae ad Plantas Asiaticas Vol. 4: 665 (1854)

Other Literature: M. Percival and J.S. Womersley, Floristics and Ecology of the Mangrove Vegetation of Papua New Guinea 82 (1975) Fig. 61-63.


Family: Rhizophoraceae
Dicotyledon
Yes. Non-timber species

Field Characters: Large trees up to 25 m high or small trees 4-12 m high. Bole cylindrical up to 40 cm diam.; straight; buttresses absent; spines absent; aerial roots present; stilt roots present. Bark black, grey, or brown, rough, fissured both longitudinally and transversely; subrhytidome pink or red; bark thickness <25 mm thick; blaze consisting of one layer; faintly to non-aromatic; outer blaze brown, red, or pink, markings absent, smooth; inner blaze pink, red, or brown, markings absent, smooth; exudate absent. Terminal buds not enclosed by leaves; complex hairs absent; stinging hairs absent; mature twig without hairs.

Leaves: Clustered at end of branches <internodes indistinct>. Leaves opposite, simple; petiole present about 20 mm long, not winged, attached to base of leaf blade <not peltate>, not swollen; lamina broadest at or near middle, 6.5-16.0 cm long, 3.0-8.0 cm wide; lamina symmetric, margin entire, not dissected or lobed, apex bluntly mucronate, venation pinnate <secondary veins arising from the midrib along its length>, secondary veins open <spaced far apart to easily see tertiary veins>, not prominent, but visible on upper surface, intramarginal veins absent; lower surface green, upper surface glossy dark green, hairs absent; oil dots absent; domatia absent; stipules present, free <from one another> but clasp each other, joined across twigs <growing between opposite leaves and leaving a scar between them when they fall; interpetiolar>, almost encircling the twig <amplexicaul>, leafy, not fringed, large <easily visible to the eye> 25-60 mm long, not persistent.

Flowers: Inflorescence axillary <from between a leaf and branch>. Flowers on a branched axis with 2 or 4 branches; flowers bisexual, stalked pedicels 4-10 mm long, with many planes of symmetry <actinomorphic>, 5.0-8.0 mm long, small (< or =10 mm diam.) 5-7 mm diam.; perianth present, with distinct sepals and petals, white or yellow; inner perianth 4 (not persistent), free; stamens 8 (4 + 4), filaments present short, free of each other, free of perianth; ovary partly inferior <perigenous>, carpels joined (when more than one) <syncarpous>, locules 2; styles solitary <including joined together> 4-6 mm long, 1.

Fruits: Fruits arranged on branched axis. Fruit 25-40 (Seedling (hypocotyl) germinates on the plant, breaking through the fruit and becoming very long before ripening and falling) mm long, c. 20.0 mm diam., fruit dull green or dull brown, not spiny but with slightly rough surface, non-fleshy, simple, indehiscent, drupe. Seeds 1 (-3) (very rarely), not winged, as wide as long.

Distribution: Western, Morobe, Madang, Gulf, Milne Bay, Central & New Ireland.


Rhizophora stylosa
Botanical records
in PNGplants database

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