Open Access

Greg Steenbeeke

• The species Sarcochilus dilatatus F. Muell. is an Australian endemic orchid, recorded in south-eastern Queensland and the upper north-east of New South Wales (NSW), between the Kroombit Tops (Calliope Range — inland from Gladstone) Queensland (Walsh 1997) and the Richmond River New South Wales (Jones 1988). The species occurs along the coast and lower ranges, up to 400 m altitude (Weston 1993) where it is epiphytic. It appears to favour Araucaria cunninghamii (Hoop Pine) above all other hosts, and germinates on smaller stems about 8–12 mm diameter, which are in the higher, brighter parts of the crown. The largest population of the species I have seen, south-west of Bundaberg, Queensland, was within a plantation of Hoop Pine, a "habitat" which Walsh (1997) also considers extremely rich in this otherwise rare species. Identification of Sarcochilus dilatatus requires flowers for confirmation, although the foliage is also quite distinctively marked. A net-like pattern of reddish rectangles occurs across the foliage, with a background colour of green. Often this network pattern is only visible when light is transmitted through the foliage. Leaves on most individuals are few, falcate, and borne on a short stem. The roots are long and slender, mainly white, although older roots will be grey. The inflorescences are axillary, generally pendent, and mostly only one is produced from each axil at any one time, although the axil may produce a number of inflorescences in successive years. Older, larger plants may have a number of inflorescences concurrently (the confirmation specimen was carrying three racemes), but the most common situation is for only one or two racemes per plant. The flowers are small, star-shaped, mainly brown or brownmarked on a greenish background, and have a white labellum variously marked with orange. The tepals are distinctly spathulate.