Argophyllum heterodontum

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Argophyllum heterodontum
Herbarium specimen
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Argophyllaceae
Genus: Argophyllum
Species:
A. heterodontum
Binomial name
Argophyllum heterodontum
Synonyms[2]

Argophyllum heterodontum is a plant in the Argophyllaceae family endemic to a small part of north eastern Queensland. It has an affinity to A. lejourdanii and was described and named in 2018.

Description[edit]

Argophyllum heterodontum is a straggly shrub growing to 2–6 m (6 ft 7 in – 19 ft 8 in) tall. New growth is covered in rusty brown hairs, which become creamy white when more than 10 cm (3.9 in) from the tip. The leaves are held on petioles up to 35 mm (1.4 in) long, are simple, alternate and highly discolorous - the upper sides are green and the lower sides are silvery white. They are elliptic to ovate with toothed margins and 6–10 lateral veins either side of the midrib, and they measure up to 14 cm (5.5 in) long by 5.5 cm (2.2 in) wide.[4][5]

The inflorescences are panicles produced in the leaf axils - they are covered with dense, matted, woolly hairs, and may reach up to 9 cm (3.5 in) long. The small flowers are actinomorphic (i.e. with multiple lines of symmetry) and have both pistils and stamens. They have 5 fused greenish sepals with lobes about 1.5 mm (0.06 in) long, and 5 white petals about 3.5 mm (0.14 in) long. The 5 stamens are about 1.5 mm (0.06 in) long, as is the style.[4][5]

The fruit is a capsule about 4 mm (0.16 in) long and 5 mm (0.20 in) diameter.[4][5]

Taxonomy[edit]

This species was first described, along with a number of other new species in the genus, in 2018 by the Australian botanists Anthony Bean and Paul Forster. Their paper, titled "A taxonomic revision of Argophyllum J.R.Forst. & G.Forst. (Argophyllaceae) in Australia", was published in the Journal Austrobaileya. The type specimen was collected by Forster in 2003 at Walshs Pyramid, about 20 km (12 mi) south of Cairns.[4][5]

Etymology[edit]

The genus name Argophyllum is derived from Ancient Greek Árgos meaning white or shining, and phúllon meaning leaf. It refers to the white colouration of the underside of the leaves.[4] The species epithet heterodontum is from héteros meaning different, and odóntos meaning tooth. It refers to the variable size of the teeth on the leaf margin.[2][4]

Distribution and habitat[edit]

A. heterodontum is restricted to a very small area of the Wet Tropics of Queensland, mostly in the area of Walsh's Pyramid, and with a disjunct population around Butchers Creek Falls to the south-west.[4][5] It inhabits gallery forest and rock outcrops on the margins of rainforest. The Walsh's Pyramid population is on very thin soil derived from granite, while at Butchers Creek they grow on basaltic and metamorphic soils.[4]: 218  The total area of occupancy of this species is just 36 km2 (14 sq mi).[6][a]

Conservation[edit]

Whilst this species is listed by the Queensland Department of Environment and Science as least concern,[1] Bean and Forster recommended in their paper that it should be given the rating of vulnerable, arguing that it may be affected by burning and weed invasion (while most of the population occurs in National Parks, some occurs on freehold land). At the same time, they also accepted that there is no immediate threat to the species.[4]: 219 

As of 24 January 2024, Argophyllum heterodontum has not been assessed by the International Union for Conservation of Nature.

References[edit]

  1. ^ a b "Species profile—Argophyllum heterodontum". Queensland Department of Environment and Science. Queensland Government. 2019. Retrieved 30 August 2021.
  2. ^ a b c "Argophyllum heterodontum". Australian Plant Name Index (APNI). Centre for Plant Biodiversity Research, Australian Government. Retrieved 30 August 2021.
  3. ^ "Argophyllum heterodontum A.R.Bean & P.I.Forst". Plants of the World Online. Royal Botanic Gardens, Kew. 2024. Retrieved 24 January 2024.
  4. ^ a b c d e f g h i Bean, A.R.; Forster, P.I. (2018). "A taxonomic revision of Argophyllum J.R.Forst. & G.Forst. (Argophyllaceae) in Australia" (PDF). Austrobaileya. 10 (2): 207–235. Retrieved 30 August 2021.
  5. ^ a b c d e F.A.Zich; B.P.M.Hyland; T.Whiffen; R.A.Kerrigan (2020). "Argophyllum heterodontum". Australian Tropical Rainforest Plants Edition 8 (RFK8). Centre for Australian National Biodiversity Research (CANBR), Australian Government. Retrieved 30 August 2021.
  6. ^ "Spatial Portal". Atlas of Living Australia. Retrieved 24 January 2024.

External links[edit]

Notes[edit]

  1. ^ For a definition of Area of Occupancy see this page at the Atlas of Living Australia