Indian hawthorn is native from China to south-eastern Asia.
Naturalised in S. E. Queensland they are an environmental weed in Brisbane.
They, and their cultivars are common in Brisbane.
They are often seen as a small shrub around 1 to 2 m high and wide.
Occasionally they grow as a small tree 4 to 6 m high.
Young green or purplish stems become grey-brown and woody.
Brown hairs on young stems are mostly lost on older ones.
Old stems have lenticels (nodules).
Plants have a wide deep root system.
Alternately arranged leaves are clustered at the branch ends.
The tough leathery leaves are on a petiole up to 2 cm long.
The petiole usually has simple brown hairs.
At the petiole base are tiny hairy stipules with a pointed tip that fall early.
Leathery blades are from 3 to 8 or 10 cms long and up to 4 cm wide.
Shape varies from ovate to oblong, elliptic or sometimes obovate.
The tips can be pointed or rounded.
They have sharp teeth on the whole edge or just around the tip.
Young leaves have brown hairs that are lost on older leaves.
The upper surface is a shiny dark green, the lower surface is paler.
New growth may be pinkish.
The up to 12 pairs of lateral veins are most obvious on the lower surface.
There is a reticular network between them.
Terminal inflorescences are a dense cluster of flowers.
They can be a raceme (unbranched stem with flowers on a pedicel that open from the bottom first) or panicles (branched).
All the branches have brown hairs that are lost over time.
There are bracts at the base of the peduncle(s) and bracteoles on the pedicels.
The narrow lance-shaped bracteoles, up to 7 mm long fall early.
Inflorescences 3 to 8 cm long hold a few to many flowers.
Flowers are on a pedicel from half to 1.5 cm long.
Flowers have a tubular hypanthium of fused sepal, petal and stamen bases.
Initially it has brown hairs that may be lost on old flowers or fruit.
The 5 sepal lobes on the rim of the hypanthium are around 5 mm long.
The green or red lobes are narrow and have a pointed tip.
They fall after the flowers open.
There may be brown hairs on both sepal surfaces or they can be smooth.
There are 5 petal lobes with a narrow claw base that has some hairs.
When fully open the flowers are around 1 to 1.5 cm across.
The obovate petal lobes are white or tinted slightly pink.
There are around 15 stamens on the hypanthium rim.
The inferior ovary, fully in the hypanthium has 2 or 3 locules.
The 2 or 3 styles are fused just at the base.
There may be some hairs on the top of the ovary and the base of the styles.
The almost spherical fruit are pomes 5 to 10 mm wide.
They mature from green to a purplish or bluish-black.
The fallen sepal lobes leave a scar around the top.
Fruit have 1 or 2 seeds.
Japanese hawthorn, R. umbellata has wider leaves with a smooth edge or only a few teeth at the tip.
J.F.
