72 K.EW BULLETIN VOL. 46(1)
Hildegardia (Sterculiaceae) new to Australia
MARTIN CHEEK* AND GREG LEACHI
The range of the genus Hildegardia (12 species) previously known from. 1 species
in Cuba, 3 species in Africa, 3 in Madagascar, 1 each in India, China,
Philippines (IVtindoro) and Indonesia (Sumbawa), is now extended to
Australia with the discovery of a new species. The species is known from 2
populations comprising several hundred individuals in semi-deciduous vine
thicket and merits a conservation rating of 2RC- (Briggs & Leigh, Rare or
Threatened Australian Plants. Aust. Nat. Parks and Wildlife Service.
Special publication No. .14 (1988)). While there appears to be no current
threat to these populations, the conservation status may need reappraisal
should imminent mining proposals for the area proceed.
Hildegardia australiensis Leach & Cheek sp. nov. a H. sundaica Kostermans
Galicis lobis extra squamis peltatis' longe ciliatis (ciliis 10-14 brunneis
±distantibus 0.1-0.2 mm latis obsitis, Galyce intus sparse pubescenti,
androgynophoro stipito et apice tereto angustoque medio fusiformi tumido;
florens ubi decidua differt. Typus: Australia, Brennan 707 .(holotypus DNA;
isotypi BRI, K, NSW, QRS).
Deciduous tree 7-10 m tail. Bark light grey, smooth with fine longitudinal
fissures. Branchlets with a thick, white, exfoliating, waxy epidermis.
Leaf-blade entire, digitately 7- nerved at the base (incomplete material).
Infloresences borne when leafless, (1—)3(—6) per branchlet, 2—4 X 2-3 cm,
covered in flattened, brown, peltate scales, each fringed with 10—14 arms,
0.1-0.2 mm wide altogether; bracts caducous; pedicels 2-3 mm long. Male
flowers highly scented. Calyx 9-1 1 mm long, divided almost to the base; lobes 4
or 5, valvate, reflexed at anthesis, strap-shaped, 2 mm broad, apex rounded,
the inner surface with a dense basal tuft of erect shining hairs, to 1.5 mm long,
otherwise sparsely pubescent with ± appressed, weak simple hairs ± 0.1 mm
long, subglabrous towards the apex, outer surface thickly covered with peltate
scales as the inflorescence. Androgynophore c. 7 mm long, the basal part
terete, c. 3 mm long, 0.3 mm wide, the central fusiform swelling 3—3.75 X
1.5—1.8 mm, the basal 1—1.25 mm covered with mi-nute, appressed, simple
hairs, the uppermost part terete, 1 X 0.6 mm; anthers 8-10 in a globose head 1
X 1.75 mm. Carpels absent. Female flowers unknown. Fruits apocar-
pous, with 4—5, 1-2-seeded, inflated and winged fruitlets, each with a wiry
stipe 2.5-3.3 cm long, very thinly woody to chartaceous, the basal inflated
part ellipsoid and as long as the wing, overall fruitlet 7-8.2 X 2.8-3.8 cm,
glabrous inside. Seed spherical, ± 1 cm diameter.
AUSTRALIA. Northern Territory, Kakadu National Park, Graveside Gorge:
5 Aug. 1974 (fl.), G. Brown s.n. (DNA); near Pul Pul, 13° 34'S, 132° 35'E,
26 June 1990 (fr) Brennan606 (DNA, K, QRS); 11 Aug. 1990 (fl.) Brennan 707
(holotype DNA; isotypes BRI, K, NSW, QRS).
* Royal Botanic Gardens, Kew
j: Northern Territory Herbarium, P.O. Box 496, Palmerston 0831, Australia