epiphytes – Page 2

Growing Sarchochilus hartmanii in Adelaide 1983 and Now

In 1983, Ron Robjohns, NOSSA’s first treasurer, wrote a comprehensive series of articles about growing epiphytes in South Australia. Thirty years on Ron’s information for growing is still helpful and applicable for today. Any updates or extra information are in black text.

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL
Volume 7, No. 10, November, 1983
GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns
Sarcochilus hartmanii (Hartman’s Sarcochilus)
This has a range from the Hastings River in north-eastern New South Wales to the McPherson Ranges in southern Queensland, although some authorities extend this to the Atherton Tablelands in northern Queensland.
S. hartmanii is lithophytic and is normally found growing on rocks, sometimes forming large masses but usually in small clumps, however, it occasionally grows on trees. It varies in its habitat from bright sunny positions on cliff faces, above 600 metres, to shady seepages. It must be remembered, however, that this is an area of high summer rainfall and in late summer and autumn has considerable cloud cover with accompanying high humidity.

The leaves, 4 to 9 per stem, from 10 to 20cm long, 1 to 2cm across, are thick, fleshy, deeply channelled and slightly twisted at the base.

Racemes are 6 to 25cm long with 5 to 25 flowers usually sparse at first then crowded towards the apex. The flowers are 2 to 3cm in diameter and have petals and sepals of glistening pure white with deep maroon or crimson spots near the base, though sometimes all white.

The flowering period is September to November.

In 1979 a clone of Sarcochilus hartmanii “Kerrie” was awarded AM/AOC. It was a large plant with 16 spikes and approximately 320 flowers measuring 31mm across the petals.

It adapts well to cultivation and is not difficult to grow, doing well in a shadehouse with 60-70% shade and a good air circulation. I have it growing and flowering in a plastic pot in a bark, charcoal* and polystyrene foam mix and would suggest underpotting rather than overpotting. Good drainage is essential. Other growers recommend shallow baskets or rafts about 8 mm of stag-horn fern fibre as this allows the plant to spread more naturally. It likes to be kept moist (not wet), prefers a humid atmosphere and does not object to regular year-round (½ strength) doses of foliar fertiliser.

*Charcoal is not used today.

Growing Dendrobium aemulum in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL

Volume 7, No. 9, October, 1983

GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns

Dendrobium aemulum (Iron Bark Orchid)

There are several growth forms of this orchid due probably to the wide variety of habitats, the flowers of all forms being similar. It has a range from the Clyde River in south eastern New South Wales to the Atherton Tablelands in Queensland

Those growing in the rainforests of New South Wales and Queensland have straight stems up to 20 cm long with 2-4 shining dark green leaves. On the edge of the rainforests in northern New South Wales and southern Queensland in the dense brush forest, the principal hosts are the trunks of “Brush Box” trees where it has stems up to 30 cm long which tend to radiate from a central point. It also has 2-4 dark green leaves. In the open forest areas its hosts are the “Iron Bark” eucalyptus trees, it has shorter (up to 7 cm), stouter (up to) 1 cm), and more crowded stems, sometimes growing into large mats and having 2-4 yellowish green leaves. On the Atherton Tablelands at an altitude of around 750 metres and with callitris trees as its favoured host, it has very slender stems of about 0.3 cm with usually only two dark green leaves.

The flowering period is August/September. One to three slender racemes (5-10 cm long) occur terminally from between the leaves or at nodes along the stem, each raceme bearing 3-20 cm diameter. The flowers are usually pure white (sometimes pale cream) with purple markings on the labellum, the whole raceme turning deep pink before withering.

This is another of our natives which to date does not appear to have attracted much attention from the hybridisers. “Emmy” aemulum x kingianum seems to be the only registered cross.

I find D. aemulum is an easily cultivated and highly rewarding plant that flowers freely with masses of feathery flowers. It grows well mounted on hardwood slabs, cork or on a paperbark branch under 50% shadecloth. Mine get about 65% shade in mid-summer and receive an occasional spray of weak foliar fertiliser during the growing period.

Reference: Dockerill “Australian Indigenous Orchids”.

Growing Dendrobium gracilicaule in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL
Volume 7, No. 8, September, 1983
GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns
Dendrobium gracilicaule
D. gracilicaule is found from Kiama in eastern New South Wales to the Bloomfield River in the south east of Cape York Peninsula in Queensland. It has one of the widest ranges of habitat of any of our epiphytic orchids, growing in the light coastal scrubs, the dense rainforests and, in the tropical areas, on the tablelands. With such a variation in altitude (from near sea-level to about 1200 metres) it follows that there is a wide variety of hosts, even occasionally growing as a lithophyte on rocks.
The stems are long, thin and cylindrical, ½ to 1 cm thick, and from 20 to 60 cm in length with 3 to 6 ovate to lanceolate, terminal leaves, 5 to 13 cm long and of rather thin, leathery texture.
The racemes are short (5 to 12 cm) and bear 5 to 14 small, cup-shaped flowers of a dull or light yellow colour having the outer sepals lightly to heavily blotched or spotted with a brown or red-brown. Occasionally they are found a brighter yellow and without blotching. The flowering season is from July to September.
D. gracilicaule must surely be one of the hardiest and easily cultivated of our Australian epiphytic orchid species as it is adaptable to almost any conditions. I have it growing and flowering on hardwood slabs, paperbark limbs and in a pot, but I think it is better if mounted. It receives 50% – 60% shade and occasional foliar fertiliser. I protect it from frost but the cold does not affect it.
It does not flower from first year stems but will flower from mature stems for several years, even after they are leafless. Although most racemes are terminal or near, I have had racemes occurring from nodes halfway along a leafless canes.
There are two natural hybrids, i.e. D. x suffusum and D. x gracillimum. D. x gracillimum is a natural hybrid between D. gracilicaule and D. speciosum in which the features of D. gracilicaule are dominant in the flower while in D. x suffusum, the natural hybrid between D. gracilicaule and D. kingianum, D. kingianum is the dominant parent. D. gracilicaule has not attracted professional hybridists, probably because the flowers are not as outstanding as many of our other epiphytes, only two crosses appear to be registered: D. Susan (D. gracilicaule x D. falcorostrum) and D. Shan Leaney (D. gracilicaule x D. gracillimum).

Growing Dendrobium pugioniforme in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL

Volume 7, No. 7, August, 1983

GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns

Dendrobium pugioniforme (Dagger Orchid)

This is an epiphyte frequently growing into large pendulous masses on the branches or trunks of trees, mainly in the rain forest areas from Mt. Dromedary on the south coast of New South Wales northwards to the Bunyah Mountains in south eastern Queensland. The stems are slender, wiry and branching, often quite long and usually tangled. Thin creeping roots develop freely from nodes at the branches.

The distinguishing feature of the numerous shiny, thick flat, ovate to lanceolate leaves is the sharply pointed tip.

The flowers are usually single but sometimes 2 or 3 per inflorescence and are 2 to 2½ cm in diameter. The petals and sepals are light green, the labellum pale with bright red or purple markings. The flowering season is September to November.

It is a reasonably hardy plant which will respond to cultivation on quite a variety of hosts. I have had success using Melaleuca, and find that it responds to a position having plenty of shade and moisture, particularly during our summer. Although in the wild it will tolerate cold conditions, (being found from near sea level to around 1300 metres), it will require shelter from our winter frosts

Most authorities designate it an epiphyte, however, in “The Orchadian” Vol. 4, No. 2, p. 24 (1972) D.L. Jones reports having found a bleached and tough looking plant growing on Alum Mountain with its roots amongst leaf litter in a crevice. Again in “The Orchadian” Vol. 7, No. 7, p. 164 (1983) G. Walsh describes ‘inter alia‘ lithophytic forms of D. pugioniforme growing in the Illawarra District of New South Wales.

In view of this it could possibly be grown in a pot, but as it grows quite readily on a slab I have felt it pointless to possibly waste a plant just to grow it in a pot. Fertilise in the growing season with foliar fertiliser at half the recommended strength.

Two naturally occurring hybrids of D. pugioniforme have been recorded – D. pugioniforme x D. tenuissimum and D. pugioniforme x D. beckleri but they are relatively rare (Ford, “The Orchadian”, Vol, 3, No. 7, p.88: Dockerill, Aust. Indig. Orch. Vol. 1, pp 370-371) and as yet it has not yet attracted the hybridists as there does not appear to be any registered crossings.

Growing Dendrobium tetragonum in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL

Volume 7, No. 6, July, 1983

GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns

Dendrobium tetragonum (Tree Spider Orchid)

A variable epiphytic species growing mainly in rainforest areas from Illawarra in New South Wales to the Endeavour River in Queensland. A favourite haunt is on trees overhanging water, often in deep shade. It has a variety of hosts (including Myrtles, Eugenias, Water Gums and occasionally Melaleuca) on which it grows into small clumps. Altitude is of little concern as it is found from near sea level to approximately 1000 metres.

The stems, which are semi-pendulous and from 6 to 45 cm long, arise from a prostrate and branching rhizome They are round, thin and wiry at the base but thickening to become rectangular (hence the name tetragonum – derived from the Greek “tetra” meaning “four-sided”), then tapering slightly before the leaves. There are from 2 to 5 leaves up to 8 cm long at the end of the stems. They are deep green in colour and often with crinkled or wavy margins.

The racemes appear from between the leaves but are short and have from 1 to 5 flowers which are widely spreading and spidery in appearance. The colour is greenish/yellow with irregular and variable brown, red and purple markings. In size the flowers are from 4 to 9 cm from the top of the dorsal sepal to the tip of the lateral sepal and they have quite a pronounced fragrance.

The var giganteum is the tropical species and ranges from the Fitzroy to the Endeavour Rivers. The flowers are usually larger, but not always, and have a slightly different colour pattern.

The plant does not lend itself readily to pot culture and should be mounted. I have it growing on Melaleuca and cork slabs, but best results have been with one mounted on a hardwood slab.

I find that it needs little more than 50% shade plus humidity and, of course, plenty of air movement. Protect from frosts. Fertilise in the growing period with foliar fertiliser at half recommended strength. A number of interesting hybrids have been produced using D. tetragonum as one of the parents. They mostly flower well and have reasonably large flowers.

Growing Dendrobium falcorostrum in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL

Volume 7, No. 5, June, 1983

GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns

Dendrobium falcorostrum (Beech Orchid)

This is one of the most attractive of the New South Wales epiphytic orchids, the common name being derived from the fact that it is only found in the forests of the Antarctic Beech, which occur in the highlands, extending from the Barrington Tops in New South Wales northwards to the McPherson Ranges in southern Queensland. However, within those forests it does occasionally grow on other than beech trees.

Due to the clearing of those forests it is fast becoming an “endangered species”.

It is a plant of the highlands and is rarely found below 900 metres, consequently it will tolerate cold conditions, however, it requires protection from frosts and needs to be grown where there is plenty of air movement.

There are from two to six light green lanceolate leaves at the top of the stem which is from 12 to 50 cm high and the mature stems are ribbed. The flowers number from four to 20 in the raceme and are intensely fragrant during the warmer part of the day. They are from 3 to 5 cm in diameter.

Flower spikes are terminal and some stems will flower for two or three years.

They are a glistening pure white to cream with the exception of the labellum which is streaked with purple. The common name is derived from the labellum, which is short and broad, bearing a fanciful resemblance to a falcon’s beak. The flowering season is from August to October.

It can be grown using either slab or pot culture using a mixture of aged pine bark, scoria* and charcoal* in a plastic pot and grown under 50% shadecloth.

Fertilise lightly during the growing season using foliar fertilisers at half the recommended strength.

Propagation is usually by division.

*NB Charcoal is no longer used and scoria can get cold and wet in winter.

Growing Dendrobium linguiforme in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL

Volume 7, No. 4, May, 1983

GROWING EPIPHYTES IN SOUTH AUSTRALIA – R.T. Robjohns

Dendrobium linguiforme (Tongue Orchid)

The plant is epiphytic or lithophytic, forming large masses on trees or rocks. Its range is from the extreme south-east of New South Wales to at least the Burdekin River in Queensland. It grows from sea-level to altitudes of around 1000 metres, but is confined mainly to the coastal areas, although it has been found up to 250 kilometres inland. The inland plants have smaller, tougher leaves than those of the coastal areas, due no doubt to the harsher conditions under which they exist. It is not confined to a specific host but is found on quite a large variety of trees.

The rhizomes are prostrate and branching with thick, tough ovate leaves, 3 to 4 cm long having distinctive longitudinal furrows on top.

The racemes, up to 15 cm long, grow from just below the base of the leaf and bears from six to 20 flowers. The flowers are usually white or cream with a number of faint purple markings on the labellum.

The flowering time is usually August-September here but earlier in the tropical areas.

It does not lend itself to pot culture but is very hardy and with a little care will grow freely on cork or hardwood slabs. I have had good success using pieces of Melaleuca on which it readily establishes itself. It receives approximately 75% shade. It should be protected from our frosts and can be fertilised using foliar fertilisers at half the recommended strength.

This is the variety of the species on which the genus Dendrobium was founded. It was first described by O. Swartz.

There are three varieties of this species, the best known of which is var. nugentii, which is a tropical form from about the Burdekin River north to Bloomfield River in the south-east of Cape York Peninsula.

This form has broader, thicker leaves which are more rounded at the apex and in addition to the longitudinal furrows it often has transverse furrows. The flowers of this form are slightly smaller and age quicker.

Growing Dendrobium kingianum in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL Volume 7, No. 3, April, 1983

GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns

Dendrobium kingianum (Pink Rock Lily)

This is possibly the best known and most variable of our native epiphytic orchids. Its range is along the coastal strip from the Hunter River in New South Wales to Rockhampton in Queensland. While it is principally a lithophyte and found growing in large mats on exposed rock faces, it is also found in shady gullies and on trees.

It has three to six lanceolate leaves up to 13 cm long on stems varying from slender stems, pseudo bulbous only at the base, to short stout pseudo-bulbous stems. The pseudobulbs are usually 8 to 10 cm long with some up to 30 cm in length; the colour varying from pale green to dark reddish green. One to three racemes of up to twelve flowers, often fragrant, are borne from the top of the pseudobulbs, the colour, while commonly pink, varies from white to purple. They are up to 25 mm in diameter having the labellum usually spotted and blotched with mauve. The flowering season is August to November.

It can be grown on slabs or trees (e.g. Jacaranda or Melaleuca) but locally, best results are obtained from pot culture – rafts or hanging baskets, using an open mix. Some growers use a commercial cymbidium mixture.

I have had good results by lining wire baskets with a thick layer of live spagnum moss and filling them with small pieces of seasoned pine bark and charcoal. I find that the plant not only grows up but also out of the sides of the basket.

Some shade is required in our summer I have had success using 50% shadecloth. Protection from our winter frosts is also necessary. Fertilise lightly in the growing season using commercial fertilisers at half strength.

Being hardy it is well suited to cultivation and hybridisation. D. x delicatum is a natural hybrid of D. speciosum and D. kingianum, also D. x suffusum is a natural hybrid of D. gracilicaule and D. kingianum.

A number of man-made hybrids are available. Some of the best known are D. Bardo Rose (D. kingianum x D. falcorostrum). D. Ella Victoria Leaney (D. kingianum x D. tetragonum), all of which respond well to pot culture and flower freely.*

Propagation is either by division or cultivation of “keikies”.

*The number of hybrids has increased since 1983.

Growing Epiphytic Orchids in Adelaide 1983 and Now

NATIVE ORCHID SOCIETY OF SOUTH AUSTRALIA JOURNAL

Volume 7, No. 3, April, 1983

GROWING EPIPHYTIC ORCHIDS IN SOUTH AUSTRALIA – R.T. Robjohns

Epiphytes usually grow where there is plenty of air movement, ample light but also shade and to achieve this they are frequently found well above the ground storey in the forest from where, should they be dislodged from their host and fall to the forest floor they wither and die. With most plants the roots grow downwards, however, with epiphytes in their natural habitat, the roots may grow up, down or around their host, that is, in any direction in search of suitable conditions.

As a novice grower I urge you to learn all you can about the natural habitat of the plant and its principal host, bearing in mind that in accounts of plants that grow on rock faces, often they are growing with their roots in crevices into which any moisture drains and maybe in an accumulation of leaf litter. Frequently the rocks on which the lithophytic orchids grow are sandstone – a rock which can absorb moisture and consequently keeps cool longer than most other rocks. “In an exposed situation” should not be construed as being in full sun all of the time: usually they receive some shade.

With the possible exception of Cymbidium canaliculatum few epiphytes grow at their best in full sun in nature. Full sun in the hot dry South Australian summer will usually burn off the plants or at the best cause severe yellowing and loss of leaves. It is to be noted that this State has no native epiphytic orchids.

Most Australian epiphytic orchids grow in the coastal belt of northern New South Wales and Queensland where the average rainfall in their DRY season is much the same as the Adelaide winter or WET season with which it coincides, consequently advice that plants require to dry out during the winter should not be taken to the extreme and the plants left without water.

The three principal requirements of epiphytes are a free air circulation, a semi-shaded position and free drainage.

In South Australia epiphytes are grown in two ways, the most popular being pot culture and the other slab culture.

For pot culture the medium must be a free draining one and a mixture of “aged” pinebark, scoria and charcoal is quite effective.

Note 2015 – Today the potting media used is composted pine bark. Charcoal is not used and scoria can get cold and wet in winter.

In choosing material for slab culture consider the conditions under which you intend to grow the plants. For humid conditions cork is ideal while tree fern, which holds moisture longer, is good for dry conditions, although any of our native trees with papery or corky bark is suitable. Perhaps you would wish to attach the plants directly to trees in your garden, for this purpose try Jacaranda, Melaleuca or trees with a similar bark.

Watering is important, slab culture requires more watering than pot culture and in summer water orchids on slabs at least every second day and every-day during a hot spell. Water according to the weather and watch for signs of stress – in wintertime the rain is usually sufficient.

Fertilising is best done using half of the recommended strength of commercial proprietary fertilisers.

As a last general recommendation – beware of frosts. Last year (1982) the frosts in some areas of Adelaide caused severe losses amongst plants of epiphytic native orchids. Large tubs of D*. speciosum, whose thick leathery leaves I mistakenly thought frost resistant, were reduced to a mass of leafless canes; even baskets of D. kingianum hanging three feet below the 50% shadecloth had all of the leaves burnt off. These were but two of the varieties which suffered, so be warned and ensure that your plants are protected from frosts.

*D. = Dendrobium

March 2015 Winning Photograph

Three winners; three very different orchids but that is typical of Australian Orchids, there is no one species that you can point to and say that is a typical orchid as illustrated by the the winners which were Sarchochilus falcatus (Kris Kopicki), Diuris palustris (David Mangelsdorf) and Simpliglottis valida synonym Chiloglottis valida (Pauline Meyers).

Sarchochilus falcatus (common name Orange Blossom Orchid) is an epiphyte. The cultivated plant in this photo originated from the Blue Mountains just north of Macquarie. Epiphytic/lithophytic orchids are found across northern Western Australia through the Top End and from a narrow band down the east coast to Tasmania; that is in all States except South Australia. About a quarter of Australian orchids are epiphytes and despite the widespread distribution, 90% of epiphytic orchids are found primarily in the rainforests of northeastern Queensland.

S. valida (common name Large Bird Orchid or Frog Orchid) and D. palustris (common name Little Donkey Orchid or Cinnamon Donkey Orchid) are terrestrial, the larger of the two orchid groups. Terrestrials are mainly found across the southern part of the continent with some occurring in the north and tropics. Their optimal habitat is the various types of sclerophyll forests found in Australia.

There is some distribution overlap but the two groups mainly occupy different habitats.

Concerning the habitat of the two terrestrials, S. valida ranges from tall moist closed forest to shaded places of drier open forests to sphagnum bogs and in the mature pine plantations of the South East. Whereas D. palustris occurs in wet and swampy habitats in the Eastern states (hence it is named from the Latin palustre meaning swampy), in South Australia it is not so. Instead it is found in open terrain of grassland, grassy woodland, mallee and shrubland.

Some Odd Facts:

S. valida is a small ground hugging plant the scape (flowering stalk) of which elongates to 10cm or more after pollination. Click on this video link to see these plants ‘talking’. In New Zealand it is described as a vagrant having been introduced from Australia.

Sarchochilus falcatus is the most common and widely distributed species of this genus in Australia. Occassionally it is lithophytic (grows on rocks). Though it had been rated Endangered and downgraded to Vulnerable in 2005, it is still under major threat from illegal collecting, trampling, water pollution, weeds and fire. New Zealand has epiphytes and the common name for them is Perching Orchids.

D. palustris is uncommon in South Australia and Tasmania; and rare in Victoria. D. palustris was one of the subjects painted by Adelaide colonial artist and cartoonist Margaret Cochrane Scott in 1890s who had an affinity for native orchids.

References:

All internet references accessed on 31^st March 2015

https://www.anbg.gov.au/cpbr/cd-keys/orchidkey/html/intro-c_habitat.html

http://anpsa.org.au/APOL19/sep00-1.html

http://www.nativeorchids.co.nz/Species/Simpliglottis_valida.html

http://data.rbg.vic.gov.au/vicflora/flora/taxon/4cebc1f9-38da-4c61-9c3c-37c2efc6da32

Mark Clements The Allure of Orchids 2014

http://www.iucnredlist.org/details/44392876/0

Bates 2011 South Australia’s Native Orchids DVD

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