Species of shrub in the family Proteaceae endemic to the Mid West region of Western Australia
Grevillea amplexans is a species of flowering plant in the family Proteaceae and is endemic to the Mid West region of Western Australia. It is a spreading shrub with arching branches, stem-clasping, sharply-pointed, lobed or toothed leaves and white to cream-coloured flowers.
Description
Grevillea amplexans is a spreading shrub that typically grows to a height of 1–3 m (3 ft 3 in – 9 ft 10 in) and has arching branches. Its leaves are 7–26 mm (0.28–1.02 in) long, 10–35 mm (0.39–1.38 in) wide and star-shaped or egg-shaped with three to seven lobes or five to eleven teeth on the edges, and a stem-clasping base. The flowers are arranged in more or less spherical to domed groups on the ends of branches. The flowers are white to cream-coloured and glabrous, the pistil 2.5–5.8 mm (0.098–0.228 in) long with a white style. Flowering occurs from July to December and the fruit is an oblong follicle 9–12 mm (0.35–0.47 in) long.[3][4]
Taxonomy
Grevillea amplexans was first formally described in 1870 by George Bentham from an unpublished description by Ferdinand von Mueller in Flora Australiensis.[5] The specific epithet (amplexans) means "encircling" or "embracing", referring to the base of the leaves.[6]
In 2000, Makinson and Wilson described three subspecies in the Flora of Australia, and the names are accepted by the Australian Plant Census:
- Grevillea amplexans subsp. adpressa (Olde & Marriott) Makinson[7] tends to have smaller leaves than subsp. amplexans and often has down-curved leaf edges;[8][9]
- Grevillea amplexans F.Muell. ex Benth. subsp. amplexans;[10][11][12]
- Grevillea amplexans subsp. semivestita Makinson[13] is distinguished from the autonym by its silky-hairy branchlets and glabrous, sometimes glaucous lower leaf surfaces.[14][15]
(Grevillea amplexans subsp. adpressa was first formally described in 1993 by Olde and Marriott who gave it the name Grevillea adpressa in the journal Nuytsia.)[16][17]
Distribution and habitat
This grevillea grows in sand on sandplains between Geraldton, Coomberdale and Moora in the Avon Wheatbelt, Geraldton Sandplains and Swan Coastal Plain biogeographic regions of Western Australia.[4] Subspecies adpressa grows in low heath between Mingenew and Watheroo,[8][9] and subsp. amplexans grows in heathland or mallee-shrubland[11][12] and subsp. semivestita occurs in shrubland and heath from Watheroo National Park to near Carnamah.[14][15]
Conservation status
Grevillea amplexans is listed as an endangered species by the International Union for Conservation of Nature, due to having an area of occupancy less than 200 km2, a severely fragmented range and a continuing decline of habitat due to ongoing clearance of roadside verges. Other potential threats to the species include altered fire regimes and competition with invasive weed species.[1]
Subspecies amplexans is classified as "not threatened" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions,[12] but subsp. adpressa is listed as "Priority One" meaning that it is known from only one or a few locations which are potentially at risk,[18] and subsp. semivestita as "Priority Two"[15] meaning that it is poorly known and from only one or a few locations.[18]
