Cerastium papuanum

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Cerastium papuanum

Description

Perennial herb, very variable, from small to medium-sized, slender, lax or sometimes caespitose, tufted or growing in cushions, up to 60 cm. Leaves densely together or widely spaced, varying in shape, 2-8 by 1-6 mm, with rounded to acutish apex, usually sessile, rather densely long-hairy on both sides when young, later subglabrous on the upper side. Flowers 4- or 5-merous, solitary or in 2-12-flowered, dense or lax dichasia; Sepals ovate, narrowly elliptic or oblong, 2-8 by 1.5-2.5 mm, obtuse or acute, with scarious margin, variously hairy outside, glabrous inside. Petals white to pale green, hairy along margin, emarginate to bifid, 1.5-11 by 0.8-3.5 mm. Stamens 2.5-9 mm, filaments with a gland at the base, anthers oblong. Ovary glabrous, globose to broadly ellipsoid, 1.5-3.5 by 0.7-3 mm, 10-ribbed or crested, styles 4 or 5. Capsule opening with 4 or 5 bifid valves, 4-6 by 1.5-2 mm. Seeds reniform or discoid, rugose, 0.7-1 mm.

Distribution

Asia-Tropical: New Guinea endemic
In Malesia: endemic to New Guinea.

Morphology

Mattfeld, l.c., divided this very polymorphous species into several subspecies, varieties, forms and subforms. His illustration on page 160 (here ) gives a good impression of the variability of the floral parts; it also clearly demonstrates that these characters show a clinal variation. In this treatment, therefore, the somewhat simplified subdivision by Van Royen, l.c., has been followed and three subspecies maintained. At the same time it should also be observed, that Van Royen in his concluding remarks on the variability emphasises that further field studies may reveal that even these subspecies cannot be maintained. We have abstained from presenting a key to these doubtful taxa.

Citation

Hoogland - in Blumea. 1958: 228
Mattf. - in Diels, Bot. Jahrb. Syst. 62. 1938: 270
Möschl - in Blumea. 1978: 157
Mattf. - in Diels, Bot. Jahrb. Syst. 62. 1938: 269
Merr. & Perry - in J. Arnold Arbor. 1942: 387
P. Royen - in Alpine Fl. New Guinea. 1982: f. 702-705, pl. 168