Alstonia constricta, commonly known as Quinine Bush or Bitterbark, is an endemic Australian endemic  shrub or small tree of the family Apocynaceae

Apocynaceae

The Apocynaceae or dogbane family is a family of flowering plants that includes trees, shrubs, herbs, and lianas.Many species are tall trees found in tropical rainforests, and most are from the tropics and subtropics, but some grow in tropical dry, xeric environments. There are also perennial herbs...

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A. constricta has an erect growth form. Growing to 12 m in height. The species is capable of producing adventitious shoot

Shoot

Shoots are new plant growth, they can include stems, flowering stems with flower buds, and leaves. The new growth from seed germination that grows upward is a shoot where leaves will develop...

s or ‘suckers’ from the root system and in this manner often forms thickets. Leaves are pubescent, narrow and lanceolate, from 5-20 cm in length.