126 DONATIACEAE ¹

Marco F Duretto ²

Perennial evergreen plants; stems short, erect, much-branched, closely crowded forming compact and hard cushions. Leaves small, numerous, spirally arranged; stipules 0. Flowers mostly terminal, usually solitary, sessile, actinomorphic, hermaphrodite; receptacle epigynous. Calyx-tube turbinate, adnate to ovary; calyx lobes 3–7, free. Petals 5–10, imbricate, free. Stamens 2–3, inserted at the innermost margin of a fleshy, nectiferous, epigynous (covers top of ovary) disk, alternate to styles; filaments free; anthers extrorse, opening by longitudinal slits. Ovary inferior, 2–3-locular; ovules numerous in each loculus, pendulous on axile placentas; styles 2–3, short, subulate; stigmas capitate. Fruit dry, indehiscent. Seeds few; testa membranous; endosperm fleshy, oily; embryo minute.

A monogeneric family with two species of Tasmania, New Zealand and sub-Antarctic South America. The family is placed in the Asterales and is sister to the Stylidiaceae (mainly Australian, also SW Pacific, SE Asia, S South America). Some authors argue for the inclusion of Donatiaceae under Stylidiaceae, often as the subfamily Donatioideae (see Lundberg 2001; Lundberg & Bremer 2003; Carolin 2007). Reuniting Donatiaceae with Stylidiaceae would unnecessarily remove the defining synapomorphies of the latter (Wege 2007).

Key reference: Wege (2007).

External resources: accepted names with synonymy & distribution in Australia (APC); author & publication abbreviations (IPNI); mapping (AVH, NVA); nomenclature (APNI, IPNI).

1 DONATIA

Donatia J.R.Forst. & G.Forst., Char. Gen. Pl. 9, t. 5 (1775).

Characters as for the family.

A genus of 2 species: D. novae-zelandiae in Tasmania and New Zealand; and D. fascicularis J.R.Forst. & G.Forst. in sub-antarctic South America.

1 Donatia novae-zelandiae Hook.f., Bot. Antarct. Voy. II. (Fl. Nov.-Zel.) 1(2): 81, t. XVIII (1852)

Cushion Plant

Illustrations: Wilson, Stewart Island Plants 121, fig. 146 (1982); Kirkpatrick, Alpine Tasmania 59, fig. 25f (1997); Cameron, A Guide to Flowers and Plants of Tasmania, 3rd edn, 29, pl. 28 (2000); Whiting et al., Tasmania’s Natural Flora 106 (2004); Simmons et al., A Guide to Flowers and Plants of Tasmania, 4th edn, 25 (2008).

A perennial, densely tufted plant forming hard compact mounds to 1+ m diam.; stems erect, closely packed, much-branched, to 10 cm long; stout fleshy adventitious roots penetrating between them. Leaves sessile, erect and ± appressed, the upper ones bright green, the lower ones brown but long-persistent, 5–6 mm long, linear-subulate, apex pointed, base widened and having in the axil dense tufts of white hairs about half as long as the leaf. Flowers about as long as the leaves, 5–6 mm diam. Sepals 5, triangular, c. 2 mm long. Petals 5, oblong, bluntly pointed c. 5 mm long. Fruit turbinate. Flowering Jan.–Mar.; fruiting Feb.–Mar.

Tas. (TCH, TSR, TWE); also New Zealand. Common in the western half of the Central Highlands as well as in the Southern Ranges and the Tasmanian West. Found on mountain summits on wet scree slopes and exposed places where snow lies for several months of the year. Often dominating bolster heath communities growing with and often coalescing with other species of cushion plants.

References