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Thursday, September 5, 2024

Cheirostylis nuda

Common name

There is no known common name that I can find for this tiny little orchid, however the orchid genus Cheirostylis to which C. nuda belongs are commonly known as fleshy jewel orchids or velvet orchids

Flower of the jewel orchid Cheirostylis nuda

I can find little recorded about this tiny species of orchid.

Distribution and Habitat

In South Arica Cheirostylis nuda are found on the upper Kwa Zulu-Natal coast north of Mtunzini growing in deep shade in leaf litter of damp to wet dune forest.

Description

Cheirostylis nuda is a terrestrial herb with a creeping, caterpillar-like, above-ground rhizome anchored to the leaf litter and ground below by fine white root hairs.

The leaves and rhizome of Cheirostylis nuda are a shiny green colour and are hairless. The flower stems on the other hand are densely covered in tiny hairs. The flowers are very small.

Flowering takes place in the late winter here in Kwa Zulu-Natal, in mid-August into September.

Cultivation

I find Cheirostylis nuda very easy to grow indoors in both plastic as well as clay pots in a coarse mixture of pure silica sand of various sizes to which I add a little sphagnum peat.

They get watered daily for most of the year slightly reducing watering at the beginning of autumn.

Feeding weekly applications of quarter strength liquid plant feed. Sprinkling of Multicote™ on the surface of growing medium at the beginning of first growth of growing season.

Article written by Michael Hickman on the

05.09.24

Please visit my websites at

https://www.hlem.co.za/indigenous_plants/plants.html

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Friday, August 16, 2024

Tetradenia riparia

Common names:

English: misty plume bush, ginger bush

Zulu: iboza, ibozane

The inflorescence of the male iboza plant

The inflorescence of the iboza plant

This plant was previously classified under the genus Iboza, which was derived from its Zulu name which refers to the aromatic qualities of the plant. Tetradenia means 'four glands' and riparia translates to 'growing on banks of rivers'.

Tetradenia riparia belongs in the mint and sage family Tetradenia riparia belongs in the mint and sage family Lamiaceae (which includes familiar culinary herbs such as thyme, sage and rosemary).

Tetradenia riparia is mostly found growing in warmer areas, on wooded hillsides, forest margins, dry wooded valleys usually growing amongst rocks.

Inflorescences

The inflorescences are branched, large bunches at the ends of the shoots. The individual flowers are about three millimeters in diameter and would appear in veins, the flowers range in color from white to lilac, and pink flowers are also found. Male flower spikes have more of the "mist" effect than the female flowers which tend to be more compact. Flowering occurs in wintertime, in South Africa from June–August when the plant is bare.

The flower of the male iboza plant

The type of display which you will get depends on whether you have a male or female plant. Male and female flowers are borne on separate plants in spikes which differ in size and shape. The male flower spikes in profusion create more of the "mist" effect than the female flowers which tend to be more compact.

The female flower of Tetradenia riparia

Leaves

The leaves are ovate-oblong to almost round or heart-shaped 30-180 x 30-140 mm, with irregularly, somewhat bluntly toothed margins.

They are a bright green colour and are slightly sticky to the touch due to the presence of whitish, velvety, glandular hairs on both surfaces.

Venation is indented above, prominent below, and they exude a strong, aromatic scent when handled.

Like many Lamiaceae species , the younger branches are distinctly four-angled in cross section

Medicinal uses

Tetradenia riparia is a medicinal plant known to the Zulu people as iBoza for which they have many uses for including the relief of chest complaints, stomachache and malaria. Inhaling the scent of the crushed leaves apparently also relieves headaches.

An essential oil extracted from its leaves has antimalarial properties.

Laboratory studies have shown that the herb contains ingredients that moderate the malaria-causing Plasmodium falciparum parasite. An extract from the leaves has also been found to inhibit bacterial growth.

I have found that a mixture of iboza and Artemisia afra wild wormwood leaves in boiling water when inhaled works well to relieve the symptoms of colds and flu.

Ecology

The pollen and nectar rich flowers attract many species of insects, in particular the Africa honeybee, Apis mellifera scutellata. This is an important forage plant for these bees in the Winter months.

Tetradenia riparia is associated with a moth (Trichoplusia molybdina) of the predominately night-flying Noctuid family.

Growing Tetradenia riparia

Tetradenia riparia is a rewarding easy to grow garden plant which is fast growing and will flower in its first year.

Plant iboza in full sun, except in very hot areas where midday shade or light shade may be beneficial.

Although Tetradenia riparia is usually found in the wild growing in poor soil in rocky localities requiring little water, in cultivation it will grow very rapidly if planted in well drained and well composted soil, at times too rapidly. To grow at its optimum, it needs to be well watered in the summer growing period but needs to be allowed to dry out and lose its leaves in winter for good flowering. rainfall areas, especially the bushveld regions. Because of this high degree of adaptability, it is also well suited to water wise gardens,

Tetradenia riparia must be pruned back hard after flowering to keep it neat and promote flowering.

Although iBoza is very drought resistant, in grows best if well-watered in the summer growing period, being allowed to dry out completely in autumn for best flowering which occurs in winter if it is leafless.

Roof Gardens

Tetradenia has proved to be a very drought resistant xerophyte when grown in poor shallow soils as a green roof plant.

Tetradenia riparia plants trialed as part of the Ethekwini Municipality Green Roof Pilot Project in early 2009 are still thriving in August 2024, over 15 years later.

Plants trialed as part of the Ethekwini Municipality Green Roof Pilot Project in early 2009 are still thriving in August 2024.

In addition, plants of iBoza have established themselves naturally in trials that I have conducted at my home. In both cases these plants have only received rainwater, never having been watered since their establishment.

This Tetradenia riparia established its self in a growing tray on my roof

Growing indoors.

After wind blown seed germinated in the pots of orchids that I am growing indoors I discovered that they grow very well indoors remaining evergreen making them very desirable indigenous greenery for indoors, however so far they have not flowered indoors.

Propagation

Tetradenia riparia is very easily propagated from cuttings, even from quite large truncheons which can simply be planted into the ground where one wants to grow them. They need do drying off or root hormones, just stick them into the ground and water occasionally until they have rooted and produced the first good growth thereafter, they can be watered normally. Just do not overwater them or they may rot. They can also be rooted in river sand, but this is probably unnecessary. To propagate Tetradenia in large numbers it is easiest to grow them from seed, but this requires an amount of propagation know how.

https://pza.sanbi.org/tetradenia-riparia

https://en.wikipedia.org/wiki/Tetradenia_riparia

https://cjmgrowers.co.za/tetradenia-riparia/

Article written by Michael Hickman on the

16.08.24

Please visit my websites at

https://www.hlem.co.za/indigenous_plants/plants.html

other blogs at

https://emalangeniforest.blogspot.com/

Saturday, May 4, 2024

Growing South African Indigenous epiphytic orchids

A few notes on Growing South African Indigenous epiphytic orchids.

Jumellea walleri

Our South African Indigenous epiphytic orchids can either be grown on mounts as they grow in nature on trees or in pots however the majority in particular the angreacoides with large fleshy roots do far better with their roots fully exposed where they get both light and fresh air movement around them which is most important for healthy growth.

Gold award winning Mystacidium braybonae with masses of healthy roots

Some of our orchids, in particular the lithophytic orchids that grow on rocks and some Polystachya species will do well in pots. The choice depends very much on which species one is wanting to grow.

Mounts

Mounts can be made of branches cut from trees, driftwood, pieces of hardwood such as Teak and balau. Mounts can also be made from plastic mesh that are sown into flat bags and filled with suitable pine bark, coconut husk moss or other suitable material which most grow well on, however they do not look very nice. For some orchids a plastic pipe with large holes drilled into it filled with coco husk chips is a very suitable mount ,

Vanilla roscheri grow exceptionally well on such a mount

Vanilla roscheri grow exceptionally well on such a mount placed in a large pot so that the roots can grow down into the growing medium in the pot. My own preference is teak when available, when not Balau also makes long lasting mounts that my pants grow well on.

Mystacidium pusillum growing indoors under LED lights

Pots and potting medium

Plastic pots are now the norm for growing orchids in pots and more recently clear plastic orchid pots are available which benefit Angraecoid Orchids with large fleshy roots that photosynthesize. As a growing medium I have the best results with many of the orchids growing them on blocks of differing sizes depending on the amount of ventilation the roots of each species grown need when grown in pots, cut from both teak and balau wood. Belau wood which is from various Shorea species is also known as Bangkirai wood.

Ansellia africana growing indoors

For lithophytes such as Tridactyle bicaudata subsp. rupestris, Rangaeris muscicola Polystachya pubescens and a few others, I use sandstone chips which they grow very well on. Sandstone chips in various sizes can be bought from suppliers of landscaping materials.

Tridactyle bicaudata subsp. rupestris growing in full sun

When to repot

The best time to split or repot monopodial growth orchids such as the angreacoides is when the plants are in active growth having just initiated new root growth. With Sympodial growth orchids they must be split or repotted just as the new pseudobulbs start forming from the base of the previous pseudobulb.

If orchid plants are split in their dormant period many species become very dehydrated or even die before the new growth starts.

Watering

This is the most problematic factor to define when growing orchids. There are so many factors to consider that vary from plant to plant and from area to area where the plants are being grown. The only advice I can give is to watch and get to know the growth requirements of the plants being grown and water to satisfy the plant’s needs. The watering requirements will vary in response to weather conditions, the time of year and the stage of growth of the plants. With good observation and experience, one will master this difficult aspect of growing vigorous healthy orchid plants.

Cyrtorchis praetermissa subsp. zuluensis

Most of my local indigenous orchid plants are growing indoors and get watered everyday year around and occasionally twice a day in the hottest summer days when I have fans running. In the hot summer months, they get watered with room temperature tap water and in the cooler months they get watered with hot water out of the geyser. The plants growing outdoors get watered most days when they have not received rain in the summer months and once or twice a week during the cooler winter months.

It is important that the plants are drenched at each watering.

Feeding

Feeding of our indigenous orchids is most important for vigorous and healthy growth. Because they come out of the bush where no one feeds them is no reason to not feed them in cultivation if one wants to grow healthy plants.

Microcoelia obovata growing indoors under LED lights in flower

I feed my plants with a vast range of different plant feeds and growth promoting agents such as Marinure, Seagro, Nitrosol, hydroponic plant feed, black tea, rooibos tea, cinnamon tea, using a different feed every week. Marinure, Seagro, Nitrosol, hydroponic plant feed I apply at 25 percent of the recommended application rate. For black green and rooibos tea one teabag per 5 liters of water. For cinnamon tea a few sticks of true cinnamon sticks are soaked in boiling water per 5 liters of water.

True Cinnamon is the inner bark of the tree, Cinnamomum verum belonging to the plant family Lauraceae.

Occasionally the plants should be soaked for at least 15 minutes in a bucket of clean water if grown indoors to prevent the harmful build up of salts in and on the plant and on the mount that can lead to sudden death if not removed.

Light

The amount of light that epiphytic orchids species require varies considerably from species to species from full sun to deep forest shade therefore it is vital to know the light requirements of the orchid species one intends to grow if one intends to grow good healthy plants that flower well. As a rule of thumb orchids that grow fully exposed to the sun will grow under 50 percent shade cloth and plants that grow in deep forest shade will survive under 50 to 80 percent shade. In both cases the plants will not grow to their full potential.

Ansellia africana growing indoors with pure yellow flowers

Orchid plants grow better, are more healthy and are less prone to fungal and bacterial diseases if grown under a well-constructed lath roof than under shade cloth.

All the orchid plants that I have trialed indoors under artificial lighting using general purpose LED light strips have grown very well.

Ventilation and spacing of plants.

Good ventilation is essential for growing epiphytic orchids in particular in the hot and humid summer months, in particular if grown indoors. During the summer the windows remain open day and night and I have fans running from first light until about 2100 hrs in the evening, I have the fans running to ensure good air movement. To assist in the plants getting adequate light and ventilation which considerably reduces fungus and bacterial attack, the plants must be placed on a slatted or mesh covered bench and have plenty of space between them. Failure to do this will result in constant infestations of fungal and bacterial diseases and the total loss of plants.

Prevention and treatment of Fungus and bacteria diseases

When growing orchid plants prevention is far better than cure, once and orchid plant has become infected by a fungal or bacterial disease it is often very difficult to cure it. In advanced cases it is far better to place the plant in a plastic bag, tie it up and put the plant in the bin. I find regular preventative spraying with a fungicide such as Dithane M45 which is an organic broad-spectrum protectant fungicide alternated with Benomyl together with good plant hygiene keeps my plants free of disease.

Aerangis mystacidii growing indoors in low light in flower

Virus infection.

There is no cure for virus infections, immediately destroy suspected infected plants because virus can spread fast through and entire orchid collection making it valueless. Here prevention is the only cure.

Scale and mealie bug.

Both scale insects and mealie bugs attack orchid plants so keep a good look out for infestations and spray immediately. As a precaution it is advisable to spray the entire collection every couple of months to keep the plants pest free. There are many suitable insecticides on the market that are relatively nontoxic to pets and to humans.

Treatment of new plants

Be very careful when obtaining new plants, never accept or introduce unhealthy plants into your collection in the hope you may be able to save them, this could and probably will end up in tears

All new plants brought into my collection are kept separate from my collection where they are first inspected then soaked in a suitable insecticide for 10 to 15 minutes followed after a day or two by being soaked in a solution of Benomyl, followed by a soaking in a solution of Dithane M45 a day later. Only thereafter are they introduced to the other plants. It pays to be safe rather than to be sorry.

Orchid roots

Strong healthy roots are the key to growing healthy orchid plants. Just a glance at the roots of an orchid plant gives a very good indication of how well the plant has been grown and how healthy it is.

Good healthy orchid roots

I have the following orchid species growing well indoors

Acampe pachyglossa

Aerangis kirkii

Aerangis mystacidii

Angraecum cultriforme

Bulbophyllum sandersonii

Bulbophyllum scaberulum

Bulbophyllum longiflorum

Cheirostylis nuda

Ansellia africana

Bolusiella maudiae

Cyrtorchis arcuate

Cyrtorchis praetermissa subsp. Zuluensis

Diaphananthe millarii

Eulophia clitellifera

Eulophia parviflora

Eulophia petersii

Eulophia streptopetala

Microcoelia aphylla

Microcoelia exilis

Microcoelia obovata

Mystacidium aliceae

Mystacidium capense

Mystacidium gracile

Mystacidium venosum

Oeceoclades lonchophylla

Oeceoclades maculata

Polystachya concreta

Polystachya fusiformis

Polystachya modesta

Polystachya ottoniana

Polystachya pubescens

Polystachya sandersonii

Polystachya tayloriana

Polystachya valentina

Rangaeris muscicola

Rhipidoglossum rutilum

Stenoglottis fimbriata

Stenoglottis inandensis

Stenoglottis woodii

Tridactyle bicaudata subsp. rupestris

Tridactyle tridentata

Vanilla roscheri

ALL that I have written above applies to most foreign epiphytic orchids.

Some technical data on the two fungicides that I use.

Mancozeb (dithiocarbamate) 800 g / kg MANCOZEB 80% WP

DOW AGROSCIENCES

Contact fungicide with protective and curative action.

DITHANE M-45™ 800 WP NT. TOXICOLOGICAL INFORMATION

Toxicological information appears in this section when such data is available.

Acute toxicity Acute oral toxicity

Very low toxicity if swallowed. Harmful effects not anticipated from swallowing small amounts.

As product:

LD50, Rat, > 5 000 mg/kg

Acute dermal toxicity

Prolonged skin contact is unlikely to result in absorption of harmful amounts

Acute toxicity to fish

very toxic to aquatic organisms

Slightly toxic to birds.

Not toxic to bees.

15 to 20 g / 10 l water

-------------------------------------------------------------------------------------------------

Benomyl (benzimidazole)

A wettable powder systemic fungicide

Toxic to fish.

20 g / 10 l water

PREVENTION OF RESISTANCE

To avoid or delay the emergence of resistant fungal strains it is recommended that BENOMYL

be mixed at recommended rates with a fungicide having a different mode of action from that of

the Benzimidazoles.

Article written by Michael Hickman on the

04..05.24

Please visit my websites at

https://www.hlem.co.za/indigenous_plants/plants.html

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Tuesday, April 30, 2024

African Monarch Butterfly and Host plant Balloon Milkweed

African Monarch Butterfly Danaus chrysippus orientalis and Balloon Milkweed Gomphocarpus physocarpus

The African monarch Danaus chrysippus orientalis butterfly which is widespread in Asia, Australia and Africa belongs to the Danainae subfamily of the family Nymphalidae, is a medium-sized very attractive butterfly with a wingspan of between 7–8 cm.

Larval food plants

In Durban the larval host plants of the African monarch Danaus chrysippus are from the plant family Apocynaceae, in particular Asclepiadoideae, Gomphocarpus physocarpus, and Stapelia gigantea being two of them.

Gomphocarpus physocarpus Balloon Milkweed

Gomphocarpus physocarpus which belongs to the vast milk plant family, Apocynaceae, is one of many host plants in its range of distribution but is probably the main host plant in the Durban area for the African Monarch butterfly, which both feeds on the nectar in the flowers and lays its eggs on the plant.

The caterpillars which are immune to the poisonous alkaloids in Gomphocarpus, have developed the ability to store them and pass them on to the pupa and adult butterfly, which use them to their own advantage making them foul-tasting and poisonous to predators.

The protection strategy of Gomphocarpus has thus been effectively used by the African monarch for its own protection.

Distribution and habitat of Gomphocarpus physocarpus

Gomphocarpus physocarpus is widespread in South Africa, occurring in the Western Cape, Eastern Cape, Kwa-Zulu Natal, Mpumalanga, Gauteng, Limpopo, North West, as well as in Swaziland, Botswana, Zimbabwe and Mozambique and northwards to Kenya. It is found growing in grassland and bushveld, often along roadsides and in disturbed areas, from the coast to 900 m above sea level. Although naturalized and widespread in South Africa for some time, it is an introduced weed, native to tropical Africa.

The seeds are dispersed by wind, aided by the tuft of silky hairs attached to each seed.

Uses

Gomphocarpus physocarpus is widely used in traditional medicine in South Africa. The roots are used to treat stomachache. Leaves are dried and ground into a powder that is taken as snuff for headaches. The milky latex is used to treat warts. Seeds are blown away from the pods as a charm to placate the ancestors. The stems are used for fiber. Fresh stems and leaves stuffed into mole holes are said to be an effective deterrent. This plant is poisonous if ingested and has caused death to sheep fed large amounts.

Gomphocarpus physocarpus is an attractive quick growing yet short lived plant for the indigenous garden that attracts masses of a large variety of insects to its showy flowers that produce plenty of nectar.

The showy flowers are followed by large bladder like fruits that when mature split to release hundreds of seeds that float on the air under shiny silk parachutes.

To have masses of these very attractive butterflies in your garden all you have to do is buy a few plants from your local nursery, be given some seedlings from a friend that has them or collect and plant your own seed which germinates and grows without much attention.

Article written by Michael Hickman on the

30.04.24

Please visit my websites at

https://www.hlem.co.za/indigenous_plants/plants.html

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