Persicaria orientalis (L.) Spach

Spach, E. (1841) Histoire Naturelle des Vegetaux 10: 537.

Prince's Feathers; Lady's Thumb

Usually flowers and fruits as a shrub about 1-2 m tall but also flowers when smaller.

Leaf blades about 12.5-14 x 6-6.5 cm, petioles about 3.5-6.5 cm long, grooved on the upper surface. Stipules connate, forming a transparent sheath about 1.5 cm long, fringed at the apex. Petiole winged for about half its length. Twigs longitudinally ribbed. Twigs, petioles, and both the upper and lower surfaces of the leaf blade clothed in a mixture of erect and prostrate hairs. Some hairs may have a glandular base and scattered sessile glands may also be apparent.

Spikes or racemes dense, about 3.5-8 cm long, and about 0.5-1 cm diam. Pedicels slender. Perianth segments about 2.6-4 mm long. Stamens seven, alternating with seven glands at the base of the tepals.

Fruits about 3-4 x 2.5-3 mm, tepals persistent at the base. Seeds about 3-3.5 x 2.5-3 mm. Embryo about 1.5-2 x 0.5 mm, cotyledons longer than the radicle.

Cotyledons linear, about 15-17 x 2 mm. At the tenth leaf stage: the base of each leaf forms a tubular sheath around the stem. Seed germination time 156 days.

Occurs in NT, CYP, NEQ, CEQ and southwards as far as south-eastern New South Wales. Altitudinal range in northern Australia from near sea level to 700 m. Usually grows near water in open forest situations but sometimes also found associated with rain forest. A cosmopolitan plant being found in many parts of the world.