Skip to main content

Service Notice

The Western Australian Herbarium’s collections management system and census were set to read-only mode on 1 October 2025. Taxonomic updates published since this time are not being reflected in Florabase, herbarium collections, or Western Australia’s taxonomic names census (Nomos). Conservation listings displayed on Florabase may also be out of date. Please refer to DBCA’s Threatened species and communities webpage for the most recent Threatened and Priority Flora List, noting that recent taxonomic updates are similarly not included. Our database migration is moving to a staging phase. We thank you for your patience as we ensure the integrity of our biodiversity data, develop new workflows, and train staff to use the new systems. Please reach out to us if you have any questions or concerns.

The notice period started at 12:00 pm on Wednesday, 1 October 2025 +08:00 and will end at 12:00 pm on Friday, 1 January 2027 +08:00.

Advanced Search

Homalanthus A.Juss.

Reference
Consp.Regn.Veg. p194 (1828)
Name Status
Current

Scientific Description

Family Euphorbiaceae.

Habit and leaf form. Trees, or shrubs; laticiferous (latex milky). Plants succulent, or non-succulent. Mesophytic, or xerophytic. Leaves medium-sized to large; alternate; spiral, or distichous; ‘herbaceous’, or leathery, or fleshy; petiolate; non-sheathing; gland-dotted, or not gland-dotted; simple. Leaf blades entire; pinnately veined, or palmately veined. Leaves with stipules. Stipules conspicuous, leafy; caducous. Leaves without a persistent basal meristem. Leaf anatomy. Urticating hairs present, or absent. Stem anatomy. Nodes tri-lacunar, or unilacunar. Secondary thickening developing from a conventional cambial ring, or anomalous; from a single cambial ring.

Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Unisexual flowers present. Plants monoecious. Male flowers without pistillodes. Entomophilous.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in racemes (with both male and female flowers in each raceme; male flowers in clusters, each cluster subtended by a bract which has 1 or 2 glands at the base; female flowers not clustered, each subtended by a similar bract). Inflorescences terminal. Flowers bracteate, or ebracteate; minute to small; regular. Free hypanthium absent. Hypogynous disk absent. Perianth sepaline; 1–3; 1 -whorled. Calyx 1–2 (in male flowers), or 2–3 (in female flowers); gamosepalous; 2–3- lobed, or entire; regular; not persistent (on female flowers of H. novo-guineensis). Fertile stamens present, or absent (female flowers). Androecium 5–50. Androecial members free of the perianth; free of one another. Androecium exclusively of fertile stamens. Stamens 5–50; polystemonous; erect in bud, or inflexed in bud. Filaments short. Anthers dehiscing via longitudinal slits; extrorse, or introrse; bisporangiate, or tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium 2 carpelled, or 3 carpelled. The pistil 2 celled, or 3 celled. Gynoecium syncarpous; synovarious, or synstylovarious (depending on interpretation of partially connate styles); superior. Ovary plurilocular; 2 locular, or 3 locular. Styles 2, or 3; partially joined (connate towards the base); simple, or forked; apical. Stigmas 2–6; dry type; papillate, or non-papillate; Group II type. Placentation axile, or apical. Ovules 1 per locule; pendulous; epitropous; with ventral raphe, or with dorsal raphe; arillate; orthotropous, or anatropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; dehiscent, or indehiscent; a capsule (tardily dehiscent in H. novo-guineensis). Seeds ovoid; endospermic. Endosperm oily. Seeds arillate (caruncle succulent). Cotyledons 2 (usually wider than the radicle). Embryo straight, or curved. Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Mustard-oils present, or absent.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. Northern Botanical Province.