The Isis tamarind is a tree up to 16 m in height. Individuals may be single or multi-stemmed often branching low to the ground. The species can form shoots where aerial stems are damaged or come in contact with the soil surface. The outer bark is soft and flaky and light brown in colour; older branches have numerous prominent raised pores whilst the young branches and leaf axes have pale brown hairs. Leaves vary in form, especially in juvenile and shoot stages, when they can sometimes be divided into leaflets on either side of the stem (4 – 18 leaflets in mature leaves, 24 – 38 in juvenile leaves). Leaflets are arranged in an alternating pattern, with the stem extending beyond the leaflets. Individual leaflets can be lobed (joined together) or pinnate (separated), with rounded or notched tips. The flowers grow in clusters of two to seven in spring and summer, borne on older branches and occasionally on the younger shoots; individual flowers are small (3 – 3.5 mm diameter), pale green and without petals. These flowers have six to eight stamens. The fruits are green, usually two-lobed and 5 – 6 mm wide by 9 mm long; they take three months to ripen. Seeds are brownish and half-enclosed by a red fleshy covering called an aril. Distinctive features of the species are its variable leaves and leaflets and the clustering of its flowers on the older branches of the tree.
Isis Tamarind |
Status: Endangered on the EPBC Act list
Government evidence of impact of climate change:
Australian Government, Conservation Advice, Alectryon ramiflorus
The sensitivity of juveniles to dry conditions makes a warming drying climate change scenario a potential future threat to the species.
It can be inferred that a climate change scenario in which the frequency or duration of drought conditions increases in the Area of Occupancy would have a severe impact on the population; especially on the ability of juvenile plants to survive through to reproductive maturity (Brown et al.; 2015).
These conditions have been caused by a range of environmental factors including drought stress; grazing; weed invasion; and high frequency of fire.
The indication is that juveniles may be sensitive to drought conditions.
The reduction in distribution of this species; as compared with its probable historical abundance and distribution; is likely to exacerbate the impact of local drought events on the species as a whole (Brown et al.; 2015).