Aglaia monocaula Pannell, 2020

Pannell, Caroline M., Schnitzler, Jan & Muellner-Riehl, Alexandra N., 2020, Two new species and a new species record of Aglaia (Meliaceae) from Indonesia, PhytoKeys 155, pp. 33-51 : 33

1. Aglaia monocaula Pannell sp. nov. Fig. 1

Diagnosis.

Aglaia monocaula resembles Aglaia flavida , from which it differs through being a smaller, unbranched tree with reticulation subprominent and no indumentum on the lamina of the lower surface of the leaflets. It is unique in the genus in having a dark blackish-brown, slightly swollen, region at the base of the petiolules.

Holotype.

Indonesia. West Papua: Kecamatan Ayfat, neighborhood of Ayawasi, fr. 12 Feb. 1995, K. Yumte 126 (L)

Tree, 3-10 m high, unbranched, with a terminal tuft of spirally inserted leaves; bole 4 cm in diameter; latex white. Twigs greyish-brown with large orange-brown pustules, densely covered with orange-brown and dark brown compact stellate hairs at the apex, glabrescent on older wood.

Leaves 47-70 cm long, 28-32 cm wide; petiole 11-30 cm long; the petiole, rachis and petiolules with few to numerous hairs like those on the twigs, glabrescent. Leaflets 15, the laterals opposite or subopposite, coriaceous, lamina 7-16 cm long 2-5.5 cm wide, elliptical, slightly up-curved at the margins, cuneate at the slightly asymmetrical base, tapering to an acuminate apex, the acumen obtuse and 10-12 mm long; lateral veins 5-14, ascending and curved upwards near the margin, not anastomosing, lateral veins and reticulation subprominent; midrib prominent below with sparse stellate scales, absent from lower leaflet surface, upper and lower leaflet surfaces minutely rugulose; petiolules 10-15 mm on lateral leaflets, slender, 20-40 mm long on terminal leaflet, all with a dark blackish-brown, slightly swollen, region at the base of the petiolules.

Inflorescences not seen.

Infructescence 11 cm long, 7 cm wide; peduncle 6 cm long, the peduncle and fruit stalks with few to numerous hairs like those on the twigs, glabrescent. Fruits 2.8 cm long, 1.8 cm wide, ovoid, pericarp bright scarlet or pinkish-red, inner pericarp white, dehiscent with three locules each containing 1 seed; seed white where attached to the central axis of the fruit by a large hilum, aril orange.

Distribution.

Known only from the area around Ayawasi village in West Papua.

Ecology.

Primary open forest on limestone ridge to 600 m, with an abundant growth of moss. Fruits eaten by kuskus.

Use.

Wood used for house beams.

Vernacular.

sapa sai (K.Yumte)

Etymology.

The specific epithet of Aglaia monocaula refers to the unbranched habit of this small tree.

Conservation.

This species is known from only two fruiting specimens collected near Ayawasi village and is therefore assessed to be Data Deficient (provisional). Further collecting and monitoring is necessary to allow more conclusive estimations about the rareness and vulnerability of the species. However, the collections seen were made 24 and 25 years ago, so the likelihood of obtaining further material from this species is not great.

Additional specimen.

Indonesia. West Papua: top ridge of limestone hills south of Ayawasi village, fr., 1 May 1996, Polak 1221 (FHO)

Notes.

This new species is represented by two fruiting specimens of monocaul trees that have leaves with a long petiolule on the terminal leaflet.

Figures

Figure 1. Aglaia monocaula Pannell A habit B detail of lower surface of the leaflet C apical shoot subtending infructescence in a leaf axil D part of the infructescence with fruits cut transversely to show the three seeds and longitudinally to show the junction between the two peltate cotyledons typical of the genus Aglaia (Drawn by Rosemary Wise, edited by Alexandra Muellner-Riehl).