Bol. Soc. Brot., Ser. 2, 57: 52, 53, 55, pls IC, E; IIG-I; IIIC, I, J-L (1984)
A tropical, fibrous-rooted perennial plant with a flat, basal rosette of reddish leaves, small at anthesis, later enlarging; leaves deciduous in the dry season as plant retreats below the soil surface to its bulb-like structure for dormancy.
Leaf – lamina reniform, at the peak of maturity 1.5 cm long, 2 cm wide; retentive glands around margins of the lamina, smaller glands within; lower surface prominently veined fan-like, and sparsely covered with non-glandular white hairs; petiole oblanceolate in outline, 10 mm long, 2 mm wide near base, dilated to 3.5 mm wide near the center, then narrowing to 3 mm wide at lamina, glabrous above, the margins and lower surface sparsely covered with white hairs.
Inflorescence – 1 or 2, racemose, up to 8 cm long; flowers about 12; pedicels 3–5 mm long; scape and inflorescence with sparse white hairs.
Sepals elliptic, 3 mm long, 1.8 mm wide; margins and apex erose; surface and margins covered with white hairs.
Petals – white or pink, elliptic, 7 mm long, 4 mm wide.
Stamens 5, 2.7 mm long; filaments white; anthers and pollen orange.
Stamens – 5, 2.7 mm long; filaments white; anthers and pollen orange.
Ovary – subglobose, 0.8 mm long, 1.1 mm diam.; each carpel bilobed.
Styles – 3, white, 2.5 mm long, each repeatedly branched towards apex above centre; stigmas white, terminal.
FLOWERING: November-December. Dormancy-dry.
HABITAT: Grows in grey silty clay which is soft and malleable when moist but hard when dry.
LOCATION: N.T.— Palmerston, Berry Springs, along the Finnis River, Melville Island,
This distinctive species is common in the Palmerston region where it is found in grey silty clay. This soil type occurs in the lower alluvial zones in the laterite soils of Australia. All the species recognized to date in the Drosera petiolaris complex have particular preferences for soil type and habitat.
Natural hybrids, although rare, occur between species that grow together in the narrow band where two soil types and habitats converge. All the known hybrids have D.falconeri as one parent.
The natural hybrid between D. falconeri and D. dilatato-petiolaris was the first to be recognized in the field. The seed was collected from hybrid plants and germinated. This is unusual as, in the past, seed from Drosera hybrids has proved to be sterile.
The bulb-like structure of D. faconeri is an accumulation of fleshy leaf bases. It is positioned below the soil surface where it is safe from desiccation during the dry season. D. falconeri uses the hard dry soil encasement as insulation, whereas most species in the D. petiolaris complex use dense woolly hairs for this purpose.
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