Pomaderris betulina

Birch pomaderris
Near Paddys River, A.C.T.
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Rosales
Family:	Rhamnaceae
Genus:	Pomaderris
Species:	P. betulina
Binomial name
Pomaderris betulina A.Cunn. ex Hook [1]

Pomaderris betulina, commonly known as birch pomaderris, ^[2] is a species of flowering plant in the family Rhamnaceae and is endemic to south-eastern continental Australia. It is a shrub with hairy young stems, lance-shaped to oblong or elliptic leaves, and yellowish flowers.

Description

Pomaderris betulina is a shrub that typically grows to a height of 1–4 m (3 ft 3 in – 13 ft 1 in), its young stems covered with woolly, rust-coloured, star-shaped hairs. The leaves are lance-shaped to more or less oblong to elliptic, 15–30 mm (0.59–1.18 in) long and 5–15 mm (0.20–0.59 in) wide, the upper surface usually glabrous and the lower surface with woolly, white to rust-coloured hairs. The flowers are borne in panicles, including clusters of flowers about 10 mm (0.39 in) in diameter. The flowers are yellowish, each flower on a pedicel up to 1 mm (0.039 in) long. The sepals are 1.5–2.5 mm (0.059–0.098 in) long but fall off as the flowers mature and there are no petals. Flowering occurs from October to November. ^{[2] [3]}

Taxonomy

Pomaderris betulina was first formally described in 1833 by William Jackson Hooker from an unpublished description by Allan Cunningham and the description was published in the Botanical Magazine . ^{[4] [5]} The specific epithet (betulina) refers to a similarity of the leaves of this species to those of birch genus, Betula.

In 1997, Neville Walsh and Fiona Coates described two subspecies of P. betulina and the names are accepted by the Australian Plant Census:

• Pomaderris betulinaN.G.Walsh & Coates subsp. actensis ^[6] has leaves that are more or less flat, and sepals 2.0–2.5 mm (0.079–0.098 in) long; ^{[7] [8]}
• Pomaderris betulina subsp. betulinaA.Cunn. ex Hook. ^[9] has leaves with the edges usually curved downwards, and sepals 1.5–2.0 mm (0.059–0.079 in) long. ^{[7] [10] [11]}

Distribution and habitat

Birch pomaderris grows in forest, woodland and shrubland, often near streams, from near Torrington in New South Wales to north-eastern Victoria. Subspecies actensis is restricted to a few locations in the Australian Capital Territory and to near Burrinjuck in New South Wales. ^{[2] [3] [7] [10]}

References

1. "Pomaderris betulina". Australian Plant Census. Retrieved 8 January 2022.
2. Harden, Gwen. "Pomaderris betulina". Royal Botanic Gardens Sydney. Retrieved 8 January 2022.
3. Wood, Betty. "Pomaderris betulina". Lucid Keys. Retrieved 8 January 2022.
4. "Pomaderris betulina". Australian Plant Name Index. Retrieved 8 January 2022.
5. Hooker, William Jackson (1833). "Pomaderris betulina". Curtis's Botanical Magazine. 60: 3212. Retrieved 8 January 2022.
6. "Pomaderris betulina subsp. actensis". Australian Plant Census. Retrieved 8 January 2022.
7. Walsh, Neville G.; Coates, Fiona (1997). "New taxa, new combinations and an infrageneric classification in Pomaderris (Rhamnaceae)". Telopea. 10: 49–50. Retrieved 8 January 2022.
8. Harden, Gwen J. "Pomaderris betulina subsp. actensis". Royal Botanic Garden Sydney. Retrieved 8 January 2022.
9. "Pomaderris betulina subsp. betulina". Australian Plant Census. Retrieved 8 January 2022.
10. Walsh, Neville G. "Pomaderris betulina subsp. betulina". Royal Botanic Gardens Victoria. Retrieved 8 January 2022.
11. Harden, Gwen J. "Pomaderris betulina subsp. betulina". Royal Botanic Garden Sydney. Retrieved 8 January 2022.