The plant genus Stylidium, commonly referred to as Trigger Plants, is an interesting and an attractive one. Two species growing at Hartman's Park, Crows Nest, are no exception. The unique Stylidium laricifolium causes much interest with its fir-like appearance. Growing in great numbers over the sandstone outcrop, it gives the impression of a pine forest in miniature. This is an attractive 30cm plant. Stylidium graminifolium had fine grassy leaves and 30cm racemes of dainty pink flowers, which gave the inquisitive an opportunity to set off the triggers with a straw of grass. The sensitive column or trigger is reflexed behind the petals and is stimulated by an insect alighting on the flower, which causes the column to spring over and descend with a hammer-like action to spread pollen on the insect visitor or, when the stigma is receptive, to receive pollen from the other plants. The family Stylidiaceae is predominantly Australian. Out of the 170 species in 6 genera worldwide, 165 species in 5 genera grow in Australia. The family is best developed in Western Australia, where over 100 endemic species occur. The overseas species are found in New Guinea, southern Asia and New Zealand. Plants of Stylidium glandulosum, S. graminifolium and S. scandens were brought into cultivation at the Royal Botanic Gardens, Kew, in 1803 from seed sent from Australia by Peter Good, who was assistant to the botanist, Robert Brown. Many of the species were also cultivated in Europe as well as England. However, gardeners in Australia have yet to appreciate fully the horticultural potential of this attractive group.

Grassy Trigger-plant Stylidium graminifolium. Family Stylidiaceae.