Description: Perennial herbs and small shrubs, branches sometimes ascending or procumbent, glabrous to pubescent.
Leaves alternate; toothed, lobed or dissected, rarely entire.
Inflorescence terminal or leaf-opposed, mostly a compound umbel, sometimes simple or reduced to one or a few flowers; bracts on compound umbels usually as many as the rays; umbellules with 2 or 3 bracteoles. Flowers bisexual, white, pinkish or pale green. Sepals conspicuous, petaloid. Petals narrow, inflexed. Stylopodium 2-lobed.
Fruit laterally compressed, oblong or ± circular; carpophore adnate to mericarp junction; mericarps 5–9-ribbed, often some ribs prominent and incurved at the base.
Distribution and occurrence: World: 20 spp., endemic temp. Aust., all States except N.T.
Text by J.M. Hart & M. Henwood
Taxon concept: Hart & Henwood 2002
| | Key to the species | |
| 1 | Leaves mostly basal, ternately dissected | 2 |
| Leaves mostly cauline, simple or trifoliolate | 3 |
| 2 | Plants 10–50 cm high, perennial; umbels exceeding the leaves; bracteoles and petals white | Xanthosia atkinsoniana |
| Plants prostrate, up to 10 cm high; umbels not exceeding the leaves; bracteoles green; petals white or reddish
Back to 1 | Xanthosia dissecta |
| 3 | Plants herbs; leaves trifoliolate, leaflets elliptic, margins entire; fruit with 5–7 ribs | Xanthosia tasmanica |
| Plants shrubs or subshrubs; leaves simple or compound
Back to 1 | 4 |
| 4 | Leaves simple, cuneate, apex 3-notched; sepals peltate; fruit glabrous | Xanthosia tridentata |
| Leaves simple or compound, elliptic or ovate, entire, crenate or serrate; sepals not peltate; fruit hirsute on the summit
Back to 3 | 5 |
| 5 | Mature stems excorticating (flaky) | Xanthosia scopulicola |
| Mature stems not excorticating
Back to 4 | 6 |
| 6 | Leaves simple or compound, if compound then with the terminal leaflet at least 1.5 times longer than the lateral leaflets | Xanthosia pilosa |
| Leaves compound with the terminal leaflet equal to slightly longer than the lateral leaflets, the leaflets similar in shape, usually with three lobes
Back to 5 | 7 |
| 7 | Trichomes on adaxial leaf surface stellate, isolated to sparse | Xanthosia stellata |
| Trichomes on the adaxial leaf surface long, simple or dendritic, dense
Back to 6 | Xanthosia ternifolia |
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