The Spermacoce of the Australia

sp. nov.

Type: 6.3 km W of Batavia Downs on road to Weipa, QLD, 23.v.2004. R.K. Harwood 1479; holo: DNA; iso: BR

Annual herb, erect, semi-erect or sprawling, to 50 cm tall; stems ribbed, glabrous. Leaf blades linear, (5-)15-55 x 1-4.5 mm, acute at the apex, gradually narrowed towards the base, glabrous at both sides or scabrous at the margins, exceptionally hairy adaxially; mid-vein slightly prominent below; secondary veins invisible; margins not callused. Stipules fimbriate; stipular base 2-3.5 mm, hairy, glabrescent; fimbriae (1-)3-5(-7), to 5.5 mm long, glabrous or hairy. Flowers subsessile in many-flowered capitula; capitula terminal, to 18 mm wide, usually subtended by 1 pair of leaves; subtending leaves more or less similar to other leaves; bracts stipuliform with setae to 4 mm long. Calyx to 0.8 mm high; lobes 4, dark coloured, often purplish, sometimes reddish, narrowly triangular, to 4 mm long, hairy at the margins. Corolla light blue to lilac blue, rarely white; tube narrowly cylindrical, (0.8-)1.3-3.8 mm long, glabrous or shortly hairy outside, glabrous inside; lobes elliptic, spreading for most of their length, (0.8-)1-2.2 mm long, with a few hairs towards the apex outside, minutely hairy inside. Stamens usually with only the upper part of the anthers exserted, rarely the whole anther well-exserted, inserted near corolla tube apex; anthers elliptic or narrowly elliptic, 0.4-0.8 mm long; filaments 0.1(-1) mm long. Style exserted, 1.1-4.5 mm long; stigma appearing shortly bilobed; nectary disc entire, c. 0.1 mm high, glabrous. Capsule obovate-oblong, 1.6-2.5 x 1-1.8 mm, glabrous or with a few hairs towards the apex; septum lamellas partly remaining attached at the valves at dehiscence. Seeds brown, elliptic, 1.4-2 x 0.6-0.8; ventral groove 1/5-1/2 of width of seed, not extending under the testa margin; testa surface usually smooth, often with undeep or deep transverse and/or longitudinal furrows; obturator not persistent.

Distribution
Queensland:

Habitat and phenology

Notes

• Clarkson 4234 is special by having hairy leaves and very small flowers (measurements between brackets).
• Waterhouse 5201: the BRI duplicate has long filaments.
• Clarkson 9368: one plant has short filaments, the other longer ones.

Etymology
Greek percnos (dark-coloured) -sepalus (sepal), referring to the dark coloured calyx lobes.

Selected specimens