Inflorescence not exceeding imbricate bracts. Male flowers with outer tepals inserted at base of floral axis; outer tepals free or fused; inner tepals inserted above on floral axis, reduced and 2- or 3-toothed, or 2 or 3 hyaline tepals, usually with small dark gland on inner surface; stamens usually twice the number of inner tepals; anthers often black. Female flowers with perianth absent or outer tepals 2 or 3, inserted at base of floral axis; inner tepals inserted above on floral axis, 2 or 3, usually erect, hyaline, sometimes with small gland on inner surface; ovary with simple style branches.
Leach (2017) highlights the distinctive sculpturing of the seed coats as a useful feature.
| | Key to the species | |
| 1 | Female flowers with perianth absent and so ovary appearing to be distinctly shortly pedicellate | Eriocaulon australasicum |
| Female flowers with 2 or 3 outer tepals and 3 inner tepals; ovary sessile | 2 |
| 2 | Leaves more than 20 cm long; inflorescence on scape 33–100 cm long | Eriocaulon australe |
| Leaves to c. 8 cm long; inflorescence on scape mostly 1–12 cm long (to 30 cm in E. scariosum)
Back to 1 | 3 |
| 3 | Involucral bracts thickened, rigid, not reflexed at maturity; seeds more or less smooth at maturity with epidermal cell outlines scarcely visible | Eriocaulon carsonii |
| Involucral bracts slender, flexible, reflexed at maturity; seeds with surface pattern obvious at maturity
Back to 2 | 4 |
| 4 | Floral bracts with white hairs; epidermal cells of seeds more or less isodiametric | Eriocaulon scariosum |
| Floral bracts glabrous; epidermal cells of seeds transversely elongated
Back to 3 | Eriocaulon nanum |
