Clematicissus angustissima is a vine in the Vitaceae family, endemic to the Geraldton area of Western Australia.
The species was first described as Vitis angustissima in 1859 by Ferdinand von Mueller, from a specimen collected by Oldfield on the Murchison River. In 1887Jules Planchon reassigned it to his newly described genus, Clematicissus, with Clematicussus angustissima being the type species.
C. angustissima is a deciduous vine growing from numerous tubers. The tendrils are leaf-opposed and the five-palmate (3âÂÂ7) leaves can be entire or deeply indented. The inflorescence is leaf-opposed and multi-flowered with congested heads. Both calyx and corolla are five-lobed. The berries are fleshy and purplish-black to black when mature.
It is found in woodlands, generally on sand or loam.