Casuarina junghuhniana, the mountain ru or red-tipped ru, is a tree in the family Casuarinaceae that originated in Java and the Lesser Sunda Islands. The species has been introduced to Pakistan and Bangladesh.
Casuarina junghuhniana is an evergreen tree growing to 15âÂÂ35 m (50âÂÂ115 ft) tall. The foliage consists of slender, much-branched green to grey-green twigs 0.8âÂÂ1 mm (0.032âÂÂ0.039 in) diameter, bearing minute scale-leaves in whorls of 9âÂÂ11. It is dioecious and the flowers are produced in small catkin-like inflorescences. The fruit is an oval woody structure, superficially resembling a conifer cone made up of numerous carpels each containing a single seed with a small wing 4âÂÂ5 mm (0.16âÂÂ0.2 in) long. Unlike Casuarina equisetifolia, Mountain Ru (C. junghuhniana) has a narrower canopy, small and neat branches. It has a straight and knotless trunk.
Like some other species of the genus Casuarina, C. junghuhniana is an actinorhizal plant able to fix atmospheric nitrogen. In contrast to species of the plant family Fabaceae (e.g., beans, alfalfa, Acacia), Casuarina harbours a symbiosis with a Frankia actinomycete.
There are two subspecies:
Casuarina junghuhniana is native to Java and the Lesser Sunda Islands. The species has been introduced to Pakistan and Bangladesh as a restoration of degraded forest areas.
Popularly grown as an ornamental plant and a windproof line. The wood of this tree is used for shingles, fencing, and is said to make excellent hot-burning firewood.