The biology and cultivation of Revwattsia fragile (Watts) D. L. Jones, a rare Queensland fern, for potential commercial production
D. Christine Cargill1, 2 and Jen Johnston1
1 Centre for Plant Biodiversity Research, CSIRO. Canberra. ACT. 2601.
2 Australian National Botanic Gardens, Canberra. ACT. 2601.
Summary. The rare, endemic fern Revwattsia fragilis (Watts) D.L.Jones, is a spectacular plant with fronds growing up to 1–2 m long. The narrow range and limited number of populations of this species, and its vulnerability to habitat disturbance, climate change and collecting predation make it an immediate priority for introduction into horticulture. The objective of this project was to establish Revwattsia fragilis as a viable horticultural commodity by determining the optimum spore germination conditions using sterile media and determining the optimum growth and horticultural conditions. Optimum germination in axenic culture was obtained using either modified Hatcher’s medium or modified Moore’s medium, solidified with Phytagel. The Revwattsia plants were slow-growing, requiring a number of years and repotting before reaching the stage of producing the large mature fronds found in wild populations. However, the developing juvenile plants are also attractive, and with time potted juveniles will grow to maturity if correctly nurtured. Revwattsia requires good drainage - the optimal growing conditions in the glasshouse were found to be a potting mix of one part decomposed pine bark to one part small pebbles, with regular watering to promote good steady growth.