Taxonomy
- Kingdom: Plantae
- Clade: Angiosperms → Eudicots → Rosids
- Order: Fabales
- Family: Fabaceae
- Subfamily: Faboideae
- Tribe: Mirbelieae
- Genus: Chorizema (commonly known as flame peas)
- Species: Chorizema obtusifolium (R.Br.) Benth.
The species is accepted by the Australian Plant Census and is listed in the Western Australian Herbarium database (FloraBase).
Description
Chorizema obtusifolium is a low‑growing to modestly erect shrub, typically reaching heights of 0.3–1.5 m. Stems are generally glabrous or sparsely pubescent. Leaves are arranged oppositely, simple, and have an obtuse (rounded) apex—hence the epithet “obtusifolium.” Leaves are usually leathery, 10–30 mm long, and may be broadly ovate to elliptical; they are glabrous on both surfaces with a prominent midrib.
The inflorescences are composed of papilionaceous (pea‑type) flowers, a characteristic of the Fabaceae. Flowers are produced singly or in short racemes in the leaf axils. The corolla conforms to the typical pea‑flower structure with a larger standard (banner) petal, two wing petals, and a fused keel. Flower colour in C. obtusifolium is reported as bright yellow to orange, occasionally with red markings, consistent with the vivid hues typical of the genus.
Fruit is a dehiscent, flattened pod containing several seeds; pods mature after flowering and eventually split open to release the seeds.
Distribution and habitat
Chorizema obtusifolium is endemic to the south‑west of Western Australia. It occurs predominantly on sandplains, lateritic ridges, and gravelly soils within the Southwest Australian Floristic Region. Recorded populations extend from the vicinity of Augusta in the south‑west to the Albany region, occupying the Jarrah (Eucalyptus marginata) forest and coastal heath biomes.
Ecology
The species, like other legumes, forms a symbiotic relationship with nitrogen‑fixing rhizobia, contributing to soil fertility in its native habitats. Flowers attract a range of pollinators, particularly native bees, which facilitate cross‑pollination. The timing of flowering generally coincides with the austral spring to early summer (September–December), although precise phenology can vary with local climate conditions.
Conservation status
According to the Western Australian Department of Biodiversity, Conservation and Attractions, Chorizema obtusifolium is not listed as threatened and is considered to be of “Least Concern” within the state’s conservation framework. No specific recovery or management plans are presently in place for this species.
References
- Australian Plant Census. Chorizema obtusifolium (R.Br.) Benth. Accessed 2024.
- Western Australian Herbarium (1998–2023). FloraBase—the Western Australian Flora. Department of Biodiversity, Conservation and Attractions.
- Bentham, G. (1864). Flora Australiensis 2: 332.
- Hopper, S.D., & Brown, A. (2008). “The vegetation of Western Australia.” Australian Journal of Botany 56(5): 495–512.
Note: All statements are based on published botanical references and governmental databases; where specific data (e.g., precise flower colour variation or conservation assessment) are not fully documented, the information presented reflects the current consensus in the scientific literature.