Utricularia australis R.Br.

Medium sized to large perennial, suspended aquatic. Rhizoids usually present, few, filiform, a few cm long, c. 0.5 mm thick, bearing numerous short, dichotomously divided branches with narrowly ovoid, papillose, apically setulose, ultimate segments. Stolons filiform, branched, up to 50 cm long or longer, 0.3-1 mm thick, terete, glabrous, the internodes 0.5-2 cm long. Leaves very numerous, 1.5-4 cm long, divided from the base into 2 ± equal, primary segments, each ± pinnately divided, the secondary segments dichotomously divided into further segments, the ultimate segments capillary, somewhat flattened, apically and laterally minutely setulose, the lateral setulae each arising from the apex of a short ± acute tooth. Traps dimorphic, usually moderately numerous, arising laterally from the secondary to penultimate segments, also at the base of the primary segments, the lateral traps ovoid, stalked, 0.5-2.5 mm long, the mouth lateral, with 2 dorsal, setiform, simple or branched appendages and usually with further, simple, lateral setae, the basal traps ovoid, stalked, the mouth basal, naked or with 2 very short, setiform, simple appendages, the internal glands of all traps 2-and 4-armed, the arms subulate, with apex subacute, up to 70 µ long and up to 12 times as long as wide, the quadrifids with the longer pair subparallel to divergent with an included angle of up to 45°, the shorter pair typically divergent with an included angle of c. 180°, but the angle varying from 30° to 200°. Inflorescence weakly erect, emergent, 10-30(-100) cm long; peduncle filiform, terete, glabrous, 1-2 mm thick, at first straight, becoming flexuous. Scales 1-(2-3), always present in the upper half of the peduncle, similar to the bracts. Bracts basifixed, approximately circular, the base auriculate, the apex rounded or obscurely tridentate, many nerved, 3-5 mm long. Bracteoles absent. Flowers 4-10, the raceme axis initially short, elongating with age; pedicels filiform, terete 1.5-3 cm long, erect at anthesis, post-anthesis spreading or, when fruit is produced, decurved. Calyx lobes slightly unequal, ovate, 3-4 mm long, the upper lobe with apex rounded, the lower lobe with apex emarginate. Corolla yellow with the basal swollen part of the lower lip much darker and with reddish brown lines and spots, 1.2-2 cm long; upper lip very broadly ovate, with apex retuse; lower lip limb reniform or transversely elliptic, the base with a very prominent swelling, the distal part ± flat, up to 1.8 cm wide, with apex rounded or retuse; palate glabrous; spur broadly conical, with apex obtuse, slightly curved, considerably shorter than the lower lip, covered, inside the whole of the distal half, with regularly distributed, subsessile glands. Filaments curved, c. 2 mm long, the anther thecae distinct. Ovary globose, densely covered with sessile glands; style distinct; stigma lower lip semicircular, ciliate, the upper lip very short or obsolete. Capsule extremely rare (seen only from China and Japan), globose, c. 4 mm in diameter, circumscissile. Seeds prismatic, 4-6 angled, c. 0.5 mm long and wide, narrowly winged on all the angles, the testa cells elongate with the anticlinal boundaries raised and the periclinal walls tabular, smooth. Flowering in Europe during the latter part of the summer, in the tropics in the wet season and in Australia in December to February.

Pools in swamps, in Malesia at high altitudes, 1300-2500 m, often not flowering. Fl. April— July, Nov.