Grevillea amplexans

Grevillea amplexans
Conservation status
Endangered (IUCN 3.1)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Proteales
Family:	Proteaceae
Genus:	Grevillea
Species:	G. amplexans
Binomial name
Grevillea amplexans F.Muell. ex Benth.[2]
Subspecies
Grevillea amplexans subsp. adpressa Grevillea amplexans subsp. amplexans Grevillea amplexans subsp. semivestita

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Grevillea amplexans was first formally described in 1870 by George Bentham from an unpublished description by Ferdinand von Mueller in Flora Australiensis.^[5] The specific epithet (amplexans) means "encircling" or "embracing", referring to the base of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]

References

This page was last edited on 20 December 2023, at 22:48