Amongst the 50+ species of orchids found so far at Rubicon, five species are listed as threatened. In our Landowner's Management Plan, we have prioritised these species according to the significance of Rubicon to their survival in Tasmania. We present below these species in priority order.
Prasophyllum limnetes is known with certainty only from Rubicon. We conducted our own analysis comparing P. limnetes with P. rostratum, which also grows at Rubicon, and found significant differences that correspond to the species description. Subsequent investigations at the Tasmanian Herbarium have failed to locate any other records.
Prasophyllum pulchellum is known from about five locations that are widely separated around Tasmania. Plants are fairly distinctive, being relatively small, compared with related white-flowered species.
Despite numerous older records, Caladenia congesta is currently thought to be quite scarce in Tasmania. Rubicon is one of the few managed sites where its status is well known.
Thelymitra mucida is known from approximately 5 sites in Tasmania, with only two sites currently known with certainty, including Rubicon. Plants are very small and only easily detected when flowers open on warm days. At Rubicon, there are two known sites, both with a relatively dense population of leaves, but with very few flowering plants each year.
Rubicon holds the largest known population of Thelymitra holmesii in Tasmania. There are numerous known sites in the north and south east of the State. Plants tend to grow in competition with sedges that can become very thick, and are most easily detected after disturbance on warm days.
The map below shows all records of orchids seen up to 2015. This is reasonably comprehensive for the rarer species, but reflects only a small sample of the common species.