Aspidostemon occultum, Werff, 2006

Werff, Henk Van Der, 2006, A revision of the Malagasy endemic genus Aspidostemon Rohwer & Richter (Lauraceae), Adansonia (3) 28 (1), pp. 7-44: 36-37

publication ID

http://doi.org/10.5281/zenodo.5186799

persistent identifier

http://treatment.plazi.org/id/03AE87F6-5D4B-FFD9-1515-7328FE0DFABD

treatment provided by

Carolina

scientific name

Aspidostemon occultum
status

 

21. Aspidostemon occultum  

Van der Werff, sp. nov. ( Figs 13B View FIG ; 14A View FIG )

A congeneris foliis   papyraceis, acuminatis, floribus depresse globosis differt.

TYPUS. — Madagascar. À la base du Mur de l’Ankarana , [12°54’S, 49°08’E], 16-28. GoogleMaps   I.1969, fl., fr., Service Forestier 28709 (holo-,   P; iso-, MO, TEF).

DESCRIPTION

Tree, to 25 m. Twigs terete, glabrous; terminal buds glabrous. Leaves opposite, 9-13 × 2.5-3.5 cm, papyraceous, glabrous, elliptic, the base acute, apex acuminate, the acumen 1 cm long, often rolled into a cylinder, the margin flat, reticulation immersed on both surfaces, lateral veins scarcely visible; petioles 7-10 mm long, shallowly canaliculate. Inflorescences to 3 cm long, glabrous, paniculate; pedicels 1-2 mm long. Flowers depressed globose, glabrous, wider than long, 2-2.5 mm in diam., tepals short, wider than long, erect; stamens 6, the outer three opening before the inner three and thus younger flowers seemingly with 3 stamens, glabrous, locelli apical; staminodia III with large, peltate apex, free or fused, upper rim of the receptacle and base of the staminodia III pubescent; staminodia IV not seen; pistil slender, glabrous, inside of the receptacle glabrous. Fruits 2.2 × 1.5 cm, ellipsoid, smooth, crowned with floral remnants.

REMARKS

Aspidostemon occultum   is best recognized by its thin, acuminate leaves, depressed globose flowers with large staminodia III. It is only known from the type collection made in the NW part of Madagascar ( Fig. 12 View FIG ). The interpretation of the number of stamens requires some explanation. In most species of Aspidostemon   the number of stamens, 3 or 6, is easy to determine. Sometimes in a species with 3 stamens the staminodial second whorl may have rudimentary locelli, which are visible as light colored patches. These rudimentary locelli do not open and can thus be recognized as rudimentary. In Aspidostemon occultum   however, most flowers have 3 stamens, but there are also some flowers with six stamens, all with opened locelli. These flowers can be considered as fully mature and the flowers with 3 stamens as not yet fully mature (the tepals cover the stamens of whorl II in these flowers) or the flowers with 6 stamens can be regarded as anomalous and ignored. I accept the first explanation: mature flowers have 6 stamens, of which the outer 3 open first and the inner 3 later. The same phenomenon has been observed in A. andohahelense   and A. manongarivense   : some flowers have 3 stamens, others 6. No vernacular name has been recorded.

ALTITUDINAL DISTRIBUTION

50-100 m.

PHENOLOGY

Flowers and fruits: January.

À

Harvard University - Arnold Arboretum

I

"Alexandru Ioan Cuza" University