The common silkpod
One of the distinguishing features of a rainforest is the presence of long-stemmed woody vines, or lianes, that grow in the soil but climb around other plants. The more tropical the rainforest, the greater preponderance of these vines. Typical of the dry rainforest around Brisbane is the common silkpod (Parsonsia straminea) which climbs using adventitious roots that arise from the stem and a twining habit to support itself on its host plant.
This vine is found along Australia’s east coast, from north-eastern Queensland south to southern NSW. It prefers to grow in well or partially shaded spots in rainforest and rainforest margins, and can tolerate a variety of moist soil types – from rich basalts to shale. The leathery, elliptical leaves, which are glossy green above and paler on the underside, come off the stem opposite each other. During spring and summer clusters of small, perfumed, tube-shaped cream/pink flowers are produced. These are followed by cigar-shaped, woody seed pods that contain numerous seeds with fine silky hairs.
This is a significant wildlife plant. The flowers attract a variety of insects such as native bees, wasps, the red clown bug and butterflies (blue tiger, swamp tiger, varied eggfly and dusky blues) as well as honey-eaters and possums. The leaves are food for the caterpillars of both the blue tiger and common crow butterflies and for possums. Ringtail possums nest in older vines. In natural conditions these actions control the rampant spread of the vine. The common silkpod lives to a great age and can quickly cover a fence or bank. If a tree is used for a support, the vine can be kept in check by pruning and cutting through the main stem. Indigenous people used the vine for string and rope construction.