Alstonia spectabilis R.Br. subsp. spectabilis

Apocynaceae

Brown, R. (1992) Australian Systematic Botany 5(6): 756.

Hard Cheesewood; Jackapple; Leatherjacket; Milkwood, Hard; Milky Yellowwood; Yellowjacket; Bitterbark; Hard Milkwood

Living bark quite bitter when chewed. Brown or orange-brown stripes in the inner blaze.

Twigs and petioles produce a milky exudate. Leaves in whorls of three or four. Leaf blades lanceolate, elliptic or obovate, variable in size but up to 36 x 12.5 cm, petioles about 1.5-2.5 cm long. Lateral veins about 18-20 on each side of the midrib, curving and often forming loops just inside the blade margin. Lower surface of the leaf blade glabrous.

Flowers about 3.5-5 mm diam. Calyx lobes about 1.5-2.2 mm long, densely pubescent on the outer surface, glabrous on the inner surface or sparsely pubescent near the apex. Corolla tube about 3.5-4.9 mm long, densely pubescent on the outer surface, lobes about 1.5-2.6 mm long, densely pubescent on both the inner and outer surfaces, with the right margins overlapping. Stamens inserted near the throat of the corolla tube. Anthers about 0.9-1 x 0.6-0.7 mm.

Fruits about 20-40 cm long. Seeds oblong, acuminate or acute at one or both ends, about 5-8 x 2-2.5 mm, hairs about 5-7 mm long.

Cotyledons narrowly elliptic, about 12-15 x 4-5 mm. First pair of leaves elliptic, about 18 x 6 mm, margins smooth, both the upper and lower surfaces of the leaf blade glabrous. At the tenth leaf stage: plant entirely glabrous. Leaf blade long and narrow, about 12 x 1.5 cm. Seed germination time 14 to 16 days.

Occurs naturally in CYP and the northern extremity of NEQ, becoming naturalised further south in NEQ. Altitudinal range from near sea level to 300 m. Grows in monsoon forest and gallery rain forest. Also occurs in Malesia (New Guinea).

Apical dominance in this species is maintained in the same way as Alstonia muelleriana.

Alstonia spectabilis R.Br., On the Asclepiadeae : 76(1810), Type: In Insular Timor prope Coepang, cum floribus fructibusque Aprili 1803 observavi. R. Brown; holo: BM. Alstonia somersetensis F.M.Bailey, Queensland Agricultural Journal 1(3): 229(1897), Type: Near Mr. Jardines house, Somerset. Alstonia longissima F.Muell., Descriptive Notes on Papuan Plants 1 : 91(1877), Type: Fly-River; DAlbertis [given by J.Monachino, Pacific Sci. 3 (1949) 161 as Fly-River; DAlbertis. Papua, 1876, No. 6424.