Sarcochilus dilatatus, Bulbophyllum globuliforme and Diuris sulphurea

© Gerry Walsh

The following article was published in the Orchadian Journal in 1993. I thought it interesting enough to reproduce it here.

In September 1993 Mr Denis Johnson and myself revisited the Calliope and Dawes Ranges, approximately 70 kms due west of Gladstone, in central coastal Queensland. We had made our first trip to the region in September, 1992. On that visit we were surprised to find both Bulbophyllum weinthalii and Dendrobium linguiforme variety nugentii to be quite abundant there about. Those observations represented an extension in distribution of 400 kms north and 400 kms south respectively to the previously recorded range of each species.

The purpose of our 1993 visit to the region was to investigate areas of hoop pine forest we had not explored in 1992. but which we suspected may harbour other species not previously recorded so far to the north. On the morning of September 13, we hiked several kilometres along dry, stony ridge tops. At one point we were surprised to find a small area of thorny bushes colonised by flowering plants of Sarcochilus dilatatus. The shrubs grew in a shallow depression surrounded by approximately two hectares of steep sun-baked rock face. The general aspect of the location was west to north-west.

The presence of many clumps of Dendrobium speciosum var. grandiflorum suggested that the shrubbery had only established after the Dendrobiums had provided a firm foothold and some organic matter in which to take root. Also growing in the same shrubbery was Plectorrhiza tridentata. Both the Plectorrthiza and the Sarcochilus dilatatus were quite stunted and surviving under harsh conditions.

In another location, at a much lower altitude, we again found numerous specimens of S. dilatutus. Conditions were far more conducive to orchid growth at this spot. The plants were in excellent condition. Some specimens were quite large. They had already finished flowering – many months earlier than this species blooms in the southern part of its range.

The three references consulted. i.e. Dockrill (1969), Jones (1989) and Upton (1992) give the northern limit of distribution for S. dilatatus as the Burnett River and Bundaberg. The Calliope Range is 150kms further north.

On the same ridge we found two separate colonies of a large yellow Diuris. Each colony supported about six plants. Photos were later shown to Mr John Riley and Mr Jim Lykos, both knowledgeable in the terrestrial orchid field, who thought them to be D. sulphurea. If so, it seems that our Calliope Range recording represents a northern extension in distribution of at least two hundred kilometres.

Later on we descended into a deep valley of dry forest dominated by pristine hoop pines, many of them of enormous proportions. We were very surprised to find good numbers of the diminutive Bulbophyllum globuliforme. They were not flowering but vegetative characteristics were identical to plants we had seen in the McPherson Range, NSW/Qld border.

The Calliope Range population of B. globuliforme colonises the same type of hoop pine limbs as the southern forms do. That is, the upper emergent limbs up to about arm thickness. The only distinction we could discern was that the southern hoop pines supporting B. globiliforme were restricted to the ridge tops. At Calliope, the host hoop pines were deep in a valley.

B. globuliforme was previously thought to be restricted to the McPherson Range. However, Jones (199l)) records it as occurring at Maleny, some l30 kms further north. Roy Gifford reports (personal communication) that he foundB. globuliforme at Jimna on the Jimna Range in 1985 at about the same latitude as Maleny. His observations were also reported in the A.N.O.S. Far North Coast Group Bulletin around 1986. The Calliope Range population of B. globuliforme represents an extension in distribution of approximately 270 kms northwards.

Epiphytic orchid species observed in the Calliope Range in September 1992 and September 2015 now total 25. These are:

Dendroblum aemulum (ironbark and brush box forms)
D. bowmanii (low altitude)
D. gracilicaule

D. linguiforme var. nugentii
D. monophyllum
D. speciosum: var. grandiflorum
D. teretifolium var. teretifolium
D. teretifolium var. aureum
Sarcochilus ceciliae
S. dilatatus
S. falcatus
S. olivaceus
S. hillii (3 plants)
S. minutiflos (low altitude)
Plectorrhiza tridentata
Rhinerrhiza divitiflora (4 plants)
Saccolabiopsis armitii (low altitude)
Bulbophyllum weinthalii
B. globuliforme
B. schrillerianum
B. minutissimum
Cymbidium canaliculatum
C. suave (1 plant)
C. madidum (1 plant)
Oberonia complanata (2 plants only)

It is hoped that a further exploration of this extremely interesting region can be undertaken in another year or so. I feel certain that other worthy finds await discovery.