Oceania
Orchids
Darryl and Alison Smedley
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Notes on the Cultivation of Sarcochilus hirticalcar By Darryl Smedley dsmedley@ozemail.com.au (This article originally appeared in The Orchadian Vol.12 No.9 September 1998) Sarcochilus hirticalcar was described by Alick Dockrill (Dockrill 1967) from material discovered by Malcolm Brown the previous year in the southern part of the McIlwraith Range, Cape York Peninsular, Queensland. It was initially described by Dockrill in the new genus Parasarcochilus, transferred to Pteroceras by Garay in 1972 (cited in Clements 1989) and then the last movement to Sarcochilus by Clements & Wallace in 1989 (Clements 1989) This last combination seems to have gained ready acceptance with orchid growers. The International Authority for the Registration of Orchid Hybrids retains the name Parasarcochilus hirticalcar for hybrid registration purposes.  S. hirticalcar is a very
attractive and desirable small-growing species. It flowers for a long period
over summer when few other native species can be relied on to produce a
reasonable display. The flowers are produced progressively along a pendant
inflorescence; nineteen per raceme being the highest count on my largest
plant. This plant has eight leaves with a maximum spread of 14 cm and
carries up to four inflorescences at a time. The smallest plants with two or
three leaves reliably produce 4-6 flowers at a time. I have even had it
flower in the bottle!
For a species endemic to a very restricted area of North Queensland, it has proved very easy to grow and produces no special challenges to the most average of cultivators. S. hirticalcar is, by definition a tropical species, the type locality being only 14°S from the Equator. However, experience has shown that S. hirticalcar does not need tropical-type conditions to be successfully cultivated. For quite some years I have successfully cultivated it outside year-round in a shadehouse in western Sydney. This comes as no surprise when the habitat at the type locality is considered. Lavarack (1980) indicates that the type locality is in vine forest along Lankelly Creek, at a place which he records is known locally as "Mulingar". This place is in the southern part of the McIlwraith Range at an approximate altitude of 400 m AMSL. The McIlwraith Range is a relatively high-altitude plateau (maximum altitude 824 m) with no other area in Australia at this latitude reaching this elevation. Rainfall is also high, estimated to be as much as 2000 mm per annum. Winter night time temperatures are in the order of 12-14°C minimum with day temperatures exceeding 30°C (Lavarack loc. cit.). The species has also been recorded along Pandanus Creek at approximately 700m where the minimum night temperature would be expected to be somewhat lower. So, here we have a ‘tropical’ species that, because of its restricted high altitude home range, can quite happily cope with at least a Sydney winter. I have a couple of dozen plants of this species and all have spent their lives outside under 50% shadecloth. The shadehouse receives maximum winter sun and is shaded by trees in summer from about midday to 5pm. They cope with winter minimums of down to -2°C on occasions and have been up to 49°C in high summer. Last decade you could sometimes get this species from a Queensland nursery but in no great numbers. Rumours persisted that it was virtually wiped out along Lankelly Creek and returning orchid travellers regularly reported that they had great difficulty in locating the species. Perhaps it was never really common in the wild. However, it has recently been found in reasonable numbers in another part of the McIlwraith Range. Fortunately, seedlings were raised from the wild-collected plants. It is from these that the plants in cultivation today are descended. The species carries its capsules for a very long time. The capsules reach dehiscence at 14½ months after pollination and, like Plectorrhiza tridentata, it is usual for the plant to be in full bloom and still carrying last year’s capsule(s). Dry seed germinates after 6-8 weeks and the protocorms are ready to replate a few months later. They grow in-vitro relatively quickly for a Sarcochilus and are large enough to deflask about 12 months after sowing. A mature flask of S. hirticalcar looks quite funny as all the roots grow up as if they’re doing everything possible to escape out the lid without touching the media in the bottom of the jar. Sibling crosses have a high degree of fertility, it seems that in selfings the germination rate is very low. Plants can be deflasked onto a mount without any special treatment. I have not attempted pot culture for S.hirticalcar, even though most of its hybrids are grown this way. Descriptions of its growth habit indicate that its relatively large and fleshy roots ascend and descend its host for some distance without entering moss pads or burrowing into the bark. They are exposed to the elements all the time, much in the manner of the more common S. olivaceus, S. australis and P. tridentata. I choose a mount as long as manageable as it’s important to give this orchid a good root run, 30 cm is adequate for a single seedling but if you’re planting multiples on the one host go to 50 cm long. Width is not critical, some of mine are on mounts only 1 cm in cross-section. I have used dressed hardwood, sawn red cedar and Cyathea treefern with great success. No pad of backing material such as sphagnum moss or tissue paper is necessary. The seedlings are tied directly onto the mount with fishing line or narrow stocking strips. The stocking is a little better as the roots of the seedling need to be forced down onto the host and fishing line can cut into them. The rapid growth of seedlings on treefern indicates this is a preferred host in cultivation, especially where the trunk has been cut vertically and the orchid’s roots can run along in and out with the fibres. It seems that the extra moisture retentive properties of the treefern suits S. hirticalcar. After mounting the totems can be hung in a low, cool, shady part of the shadehouse for a few weeks then moved a bit higher for better light and air movement once the green root tips have started to grow again. Water as with the rest of your collection, they can take lots of it. The species doesn’t seem to be as susceptible to S.S.D.S. (Sudden Sarc. Death Syndrome) as other members of the group but it’s certainly not immune, very occasionally one of mine will succumb. There appears not to be much variation in the colour and markings of the flowers from clone to clone. As the flowers are only of moderate size, about 12 mm diam., there is not a lot of potential for difference. Sometimes the yellow of the segments can be more intense. Some clones have a broader band of purple, russet or red around the basal parts of the segments and some have small blotches of these colours below the band on the labellum. Selective line breeding should be able to stabilise some of these characters. Most collections that house a variety of cool-growing orchids should be able to cope with a few S. hirticalcar. It requires no special treatment, can be fertilised or not as the case may be with the rest of the collection (although I do recommend fertilising mounted plants as they do not benefit from the inevitable breakdown of media in potted plants, fertilised or not), doesn’t need much space, flowers quickly ex flask and in summer, grows cold and produces some terrific colours in its hybrids. Its a shame its not grown and exhibited more often but I guess lack of availability or a misunderstanding of its cultural requirements has been the problem. It has proved easy to grow and there are lots of seedlings coming along from flasks so look out for it and give S. hirticalcar - the "Harlequin Orchid" a go. References
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