Cycas ophiolitica

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Figure 1. C. ophiolitica in habitat, central Queensland

Contents

Common Names:

Cycas sp. 'Marlborough Blue'

Distribution:

It now appears that the species occurs right through the ranges around Marlborough, Queensland.

Habitat:

The main habitat is in rocky, sloping and open eucalypt-forest (iron-bark country) with little vegetative surround. The soil is very poor. Much of the area contains magnasite rock which is of a hard nature. Plants occur along hilly outcrops and in lower regions near creek systems.

Could it be that the geological base determines the blueness of the fronds? If the colouring is found to be permanent after long cultivation, and in various localities, the Cycas has very good landscape potential and yet another that warrants our concern as a plant in danger. Reports at hand indicate that this Cycas grows near stands of Macrozamia miquelii and Cycas media.

Description:

It is a medium sized species having a stout caudex with a pronounced swollen base. Mature fronds are arching, especially in low specimens and are generally quite dense. The pinnae are attached to the rachis V-shaped but flattened out at a later stage. The apex is deep rusty brown and tomentose. Sporophylls are many toothed at the apex with 3 to 5 ovules per megasporophyll. Seed is light brown at maturity. An interesting observation is that the ascending centre fronds are initially sky blue and become powder blue when hardened.

Most caudices are charcoal grey, covered with dead leaf bases in diamond patterns. Offsets, severed from the parent plant, are extremely slow in forming new fronds. These Cycas all have a distinct blue colouration to both the fronds (including the rachis) and fruit. The fine, paired pinnae are very stiff with pointed apices and remain upright along the rachis throughout their lifetime. While the majority of large plants only had a trunk to 1.5m, two specimens were measured with 3m trunks. Both were in the same colony, which is the largest of any colony observed to date.

Culture:

Sunny, moist, but well drained position. Drought and frost tolerant.

Figure 2. C. ophiolitica
Figure 3. Female C. ophiolitica with seeds. Note the distinctive blue tinge to the seeds.
Figure 4. Female C. ophiolitica with young seeds.
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Introduction

Hi, my name is Scott Maclean and I live in the coastal town of Yeppoon in Central Queensland on the eastern sea board of Australia. I have a passion for cycads not only Australian species and others through out the world. To me this group of plants are simply fascinating, and all cycads have earned the right to be preserved in their natural habitat. These plants are long time residents on our planet having survived prehistoric periods and it indeed a sad to think of them as being threatened, some already are on the edge of extinction. My article is to express my own personal observations of cycads in my own back yard, particularly C. ophiolitica, a species that inhibits our nearby coastal ranges. Locally growing are various other cycads such as the Macrozamia species, M. miquelli, M. serpentina with M. moorei and M. platyrachis growing further inland. Twenty miles further north in Byfield State Forest, Bowenia serrulata grows in small scattered colonies in sandy soils on the edge of creek banks. C. ophiolitica also has two cousins, C. media to the north and C. megacarpa to the south. All three of these species closely overlap each other in some areas however we will talk about this further on.

Figure 1. C. ophiolitica in cultivation.

Destruction and Preservation

As suburbia slowly moves towards the habitat of C. ophiolitica, it is inevitable that the destruction of this plant and others is likely to occur. Here in Australia there are in place strict regulations regarding the sale and the destruction of these plants.

They never seem to go far enough though and many cycads are destroyed with out anything ever being done about it. Locally there have been rescue attempts in the past to remove C. ophiolitica and M. miquelli and replant them in safe havens, but unfortunately the destruction still quite often continues unabated. Plants are often damaged by machinery whilst clearing for new building and development. I have personally witnessed large specimens of C. ophiolitica with trunks at least thirteen foot tall, smashed and severed at their bases. Often these plants regenerate with new suckers but their fate is still sealed once buildings begin construction. Some of these plants would have to be hundreds of years old and it is awful to see them so suddenly mutilated and left to rot. A lot of times some of these plants can be saved and replanted with little or even no root system left. My method is to paint the wounds and sever any damaged roots with a sharp knife to leave a clean cut. I often then rub ash from a fire place in to the wounds and damaged roots which acts as an anti fungal. I have never lost a plant this way and have successfully rescued quite a few plants. It never ceases to amaze me just how resilient these plants can be as they have the ability to re-strike on their own after being near ripped from the ground, smashed or slashed to ground level.

It is also very fortunate that many C. ophiolitica colonies reside in ravines and at the bases of our coastal ranges rendering them reasonably inaccessible to urban development. In the nearby city of Rockhampton a native gardens was established by the local council many years ago. These gardens are unique and have on display a good variety of native cycads and palms; this is a great way to see our cycads with out having to trek through the bush. These plants have been displayed so as the public can view them up close and appreciate their beauty.

Observations in Habitat

C. ophiolitica grows with its splendid blue coloration in the Marlborough district of Central Queensland. This plant has a blue colour in its leaves, petioles and maturing seeds that is familiar with other species that inhabit North Queensland. The new flushes of this Cycas start out a splendid sky blue and become a grey green colour depending on the location of individual colonies. Plants further south however do not show signs of attaining this blue plumage and remain a deep green. Why is there such a variation of colour within the same species of this Cycas? This topic with regards to the blue coloration in all cycads around the globe, has been discussed many times in the past in various publications and by cycad growers. C. ophiolitica often grows in the habitat that M. miquelli likes too, and both species along with black boys (grass trees) co-exist together forming large colonies along hill sides and along the edges of steep gullies. Many plants from many areas have black burnt trunks which are the result of an occasional bush fire that has swept through. Although unappealing to the eye, fires do not seem to harm adult plants and they soon push through new flushes of leaves. It truly is a rewarding sight to observe a whole entire colony of these plants all with brand new leaves. Summers here are hot and the winters dry and cool, most rain falls as seasonal summer rain in the way of storms or monsoonal activity.

The word Ophiolitica can be broken down into its Greek translation as Ophios (snake)and Lithos (rock) ,which in turn can be recognized as Serpentine or snake rock. The soils in the Marlborough district are of serpentine origin ,serpentine meaning that they were formed from the breakdown of rocks that contain high concentrations of maganese, chromium or nickel. Another interesting note, is in with regards to the island of New Caledonia that also has serpentine soils. The soils here have unique specialized flora including many palms that prefer to grow only in the serpentine soils of this island. Soils on New Caledonia contain heavy concentrations of nickel, and in fact the islands main export is provided from its nickel mining. C. ophiolitica grows in serpentine soils that contain Manganese, and in some areas if one is to scratch around in the soil, you can find small lumps of this ore. Close by in the local vicinity, this manganese ore is mined and small pieces of this ore can be found on the side of the highway.

Another species of cycad also prefers these serpentine soils, and grows in small scattered colonies further south towards Rockhampton. This plant is called Macrozamia serpentina and in appearance looks very similar to M. miquelli. M. serpentina looks like a smaller version of M. miquelli but with fewer leaves and smaller cones. The question is, could the manganese content in the soil be a contributing factor to the blue colour of C. ophiolitica within this region? The population further south does not share this blue trait. I am no scientist but a ph soil test would be interesting to find out if this mineral is available to these plants. From what I can gather there appears to be many factors to consider when searching for a possible explanation and ph is only one of them, a study of some sort would be very interesting in the future. In the past I have tried several small plants in cultivation but bad seasons of chewing insects have not allowed proper flushes to emerge with out damage. Some of the smaller ones appear to have retained their blue colour but two of the larger ones in pots, have not shown any signs of new growth. Both of the larger plants in pots have been checked for new root growth, and they both have established good root systems. To find seeds on the Marlborough plants is a difficult task, especially plants that are situated not too far from the highway which makes them easily accessible to people chasing seed. Female plants occasionally seem to retain their seed with out being raided, as I have observed good seedling recruitment in quite a few localities.

Figure 1. C. ophiolitica with seeds.

Cultivation Observations

All of the seedlings that I have raised from seed have not shown any indication of the blue hue that is so prominent in the Marlborough plants. My seed has been taken from local plants in the Yeppoon area that are of a dark green origin. However one very interesting observation is that the seedlings of C. megacarpa to the south, quite often possess the same blue hue as their northern counterparts. The seeds of this species are much larger in contrast to the seed produced by C. ophiolitica, yet they quite often too are a powdery grey blue before ripening. Seed from plants in the Rockhampton and Yeppoon area are always green before changing to an orange colour closer to ripening. The seed right across the range of C. ophiolitica and C. megacarpa change to an orange colour at maturity. Plants that are grown from seed can grow much faster than in the wild and respond well to frequent applications of fertilizers and ample watering. I prefer to plant my seedling in pots that are as deep as possible so as to allow for the growth of a strong healthy root system. From time to time I also feed my seedlings a mixture of fish emulsion and seaweed extract which I believe acts like a tonic to produce vibrant healthy plants.

I have noticed that many plants can vary a lot within one locality. The range of C. ophiolitica, C. media and C. megacarpa are known to overlap in some areas and this factor may explain the many characteristics that vary so much within individual plants and colonies in Central Queensland. A common observation is in that the leaves of one species which are sometimes strongly keeled in one plant may be only moderately keeled in another, both with in close proximity of one and other. Some individuals from ranges that surround Yeppoon occasionally possess leaves that have matured into a grey-green colour, especially in their older flushes. Once again plants that are in close proximity of each other may remain the usual dark green colour.

Ripe seed that has dropped may be collected from the base of female plants and will usually strike quite easy. Some times if the adult plants are growing in a loose rocky area you may be lucky enough to obtain seed that has already struck and be easily removed with out much damage to its root system. The bright orange sclerotesta of this cycad attracts small rodents and mammals which in turn may carry the seed away from the parent plant providing a great form of seed dispersal. Often the seed themselves are covered with insect scale but this does not appear to cause any long term damage to the seed apart from discoloring the ripening outer fruit.

Plants in cultivation and in the wild often fall prey to insect activity and the result can be devastating. Some of these insects have the ability to completely devour a new flush of leaves overnight. One culprit is a pale blue native butterfly whose larvae feed entirely on cycads. Ironically this small butterfly is known as "Cycad Blue" around the city of Townsville in North Queensland. Over the years this pest scientifically known Theclinesthes onchya has had me pulling my own hair out, and has near driven me to despair. An old mosquito net draped over a frame is the best protection but it does look absolutely ridiculous to passers by, and the down side is that you may need many nets to cover several plants. Spraying is the next best option but it has to be done on a daily basis to properly destroy the grubs that constantly keep hatching from tiny pale blue to white colored eggs.

The next monster is a small bronze colored Chrysomelid beetle which also attacks the new growth on cycads. This species of beetle also likes to de-nude C. thourasii and it does so very effectively. Last year one of my adult C. thourassi tried valiantly to flush four times during the summer and the poor plant was left looking pretty ghastly. Plants growing in a garden situation also are sometimes attacked by scale insect on the seed and under leaflets, but are easily controlled by the use of pest oil. Sometimes here on the coast the southeast winds can often be relentless as well and can damage newly emerging leaves by rubbing the new growth across old growth which produces a burnt effect on the leaflets.

Conclusion

My intention, as I mentioned earlier is to share my knowledge with others on the subject of C. ophiolitica. What I have written in these pages is pretty much based on my own observations of this plant in its own environment and in my own collection. Some of my views and what I say may not be to every ones liking, however I am only writing in a way that perceive things to be. I do hope that those who have read this article have enjoyed doing so. If you are any thing like me I am starved when it comes to reading literature on any subject to do with Cycads. Thank you This is a green variant of C. ophiolitica found near Yeppoon, central Queensland.

Figure 1. Female C. ophiolitica "Green"
Figure 2. Very handsome male C. ophiolitica "Green" in habitat,Note the M. miquelli at the front.
Figure 3. C. ophiolitica "Green"
Figure 4. Male C. ophiolitica "Green" in front of M. miquelli.


Contributed by:

L. P. Butt (Text - from Palms & Cycads No. 27, Apr-Jun 1990).
Scott Maclean (Figure 1,2,3&4)

External Links:

Cycad Pages, IUCN, JSTOR, Trebrown

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