Stictocardia queenslandica (Domin) R.W.Johnson

Convolvulaceae

Johnson, R.W. (2004) Austrobaileya 6: 632.

Spotted Heart

A slender vine not exceeding a stem diameter of 2 cm. Often flowering and fruiting when quite small, e.g. less than 1 m tall or long.

Leaf blades about 10-15 x 9-17 cm, petioles about 6-20 cm long. 'Oil dots' clearly visible when the leaf blade is viewed from the upper surface while on the lower surface they look like black (or dark) glandular dots. Upper surface of the leaf blade glabrous except for a few short hairs along the main veins. Lateral veins forming loops near the blade margin.

Inflorescence usually a 3-flowered cyme, peduncle short, about 8-15 mm long, pedicels of similar lengths. Corolla lobes twisted into a spiral at the flower bud stage. Calyx lobes about 12 mm long, tightly clasping the base of the corolla tube. Corolla trumpet-shaped. Tube about 4 cm long, pink to mauve, lobes about 2-2.5 cm long, pink to mauve. Staminal filaments clothed in purple hairs towards the base. Pollen grains white, surface spinulose. Ovary surrounded by a 4-lobed collar-like disk. Stigma globular, consisting of numerous stump-like branches clothed in papillose hairs.

Fruits depressed globular, about 11 x 15-17 mm. Calyx lobes persistent, enveloping the fruit, each calyx lobe up to 20 x 15 mm. Style base persistent at the apex. Seeds up to 4 per fruit, each seed quadrant-shaped, about 7-8 x 5-8 cm. Testa clothed in short, erect, brown hairs. Cotyledons 2-lobed, crumpled and folded many times in a complex fashion. Radicle about 5-6 mm long.

Seed germination time 10 to 22 days. Cotyledons V-shaped, about 5-6.5 x 5-6.5 cm, petioles about 2-5.5 cm long. Midrib not extending to the apex of the cotyledon. First leaves cordate, apex abruptly acuminate with an apiculate tip, base cordate. Glands visible on the underside of the leaf blade. Venation palmate. Lateral veins more closely spaced towards the base of the leaf blade. At the tenth leaf stage: leaf blade cordate, apex mucronate, base cordate. Venation palmate. Lower surface clothed in dark glandular spots. Stem clothed in small spherical, honey-coloured glands which are visible with a lens. Seed germination time 7 to 143 days.

Occurs in NEQ. Altitudinal range from near sea level to 300-400 m. Grows in vine thicket and monsoon forest on lime-rich substrates.

Argyreia queenslandica Domin, Bibliotheca Botanica 89(4): 1087(1928), Type: Nord-Queensland: am Fusse eines Karsthugels bei Mungana (DOMIN II. 1910); Holo: PR. Stictocardia tiliifolia (Desr.) Hallier f., Botanische Jahrbucher 18: 159(1893).