Tuesday, November 28, 2023

Polystachya pubescens The Fine-Haired Polystachya

 

Polystachya pubescens

The Fine-Haired Polystachya

amabelejongosi (Zulu)

Distribution

Polystachya pubescens is a small compact orchid species which is common in South Africa, from the Eastern Cape in the south to Zululand, it is also found in eSwatini (Swaziland) and Eastern Zimbabwe where it is rare. This is a summer rainfall region where the plants may in some areas experience a prolonged dry season during the cooler winter months.

Habitat

Polystachya pubescens is found growing in coastal forests as well as a lithophyte out in the full sun or partial shade on sandstone outcrops. In the Pondoland region it can be found growing in large mats on sandstone rocks in the full sun, these plants are generally very small and have leaves that are a pronounced purple colour because of the intense light. In the lower light conditions of forest the plants grow much larger and are a dark green. This delightful fragrant epiphytic orchid produces bright yellow flowers in early summer. Polystachya pubescens grows in a region that has neither very high or low temperatures and is recorded as having a low tolerance for extreme cold.

Uses

Because of its showy flowers and relative ease of culture, Polystachya pubescens is a popular orchid plant amongst specialist orchid growers .

Polystachya pubescens is used extensively by the amaZulu people as a protective charm and as a love potion.

Growing Polystachya pubescens

Polystachya pubescens plant grows easily in the milder regions of the country if it is attached to a branch of a tree.

Polystachya pubescens is very easy to grow and is ideal for beginners to start with. It grows well in a small plastic or ceramic pot filled with fairly large pebbles, placing larger pebbles at the bottom of the pot and smaller ones at the top. Over a period of at least 50 years I have successfully grown them on river pebbles or crushed stone in particular sandstone as well as decaying granite. Bark may be used but it breaks down far to quickly and causes the roots at the bottom of the pot to rot.

As with all orchids never be tempted to over pot them, the rule of thumb is to put orchids and most other plants into as small a pot as possible. They can also be mounted of a slab of wood, bark, fern fiber etc. however they grow best in pots.

Light requirement

In cultivation if grown outdoors they do best in light to medium shade, under lights indoors I have found that they do well at 3500 to 5500 lux with a photo period of 16 hours in summer and 12 hours in Winter.

Ventilation

They require good ventilation, when grown indoors I have the windows open and fans running 24  hours a day during the growing season when it is hot and humid and for a few hours a day during the middle of the day in winter.

Watering and Feeding

Like most living organisms orchids tend to like to be fed daily during the growing season to remain healthy and to grow well. For those plants that need a rest period in the winter months l reduce both the amount of feed and the frequency of watering watching carefully that the plants do not desiccate.

I am a firm believer in giving a very varied diet to my plants, which I feed at very low concentrations with every watering, which is usually daily on my epiphytes and lithophytes. Once a week I give my plants a drenching with pure water to remove any buildup of harmful salts on the plants and in the potting medium.

Here is a list of what my plants get as feed and growth promoters, every day a different feed, on occasion I mix a feed and a growth promoter.

1.      Water soluble mineral fertilizer used for growing plants in hydroponics, here I used formulations for flowers and fruits.

2.      Nitrosol

3.      Seagro

4.      Fulvic acid

5.      Rooibos tea

6.      Black tea

7.      Green tea

8.      Cinnamon tea

9.      Banana skin tea

10.   Leaf mould tea

This is certainly not the only way to grow Polystachya pubescens but has worked well for me over many years to grow hundreds of strong healthy plants.

General information

The name Fine-Haired Polystachya refers to the fine hair on the lip of the flower.

About one third of orchid species possesses deceptive pollination mechanisms where no rewards are provided to the pollinators

However, many species of Polystachya appear to give rewards in the form of pseudo-pollen in the form of food hair on the lip.  Inside of pseudo-pollen food hair, Polystachya species provide protein, starch, and or lipids. Different species provide different combinations of these nutritional rewards.  The hair on the lip of Polystachya pubescens could be a reward, the main nutrients in the hairs are proteins. Although it is known that the hairs are rich in proteins, we do not know if the pollinators are in fact attracted to them because the pollination system of this species is not well studied.

 

 written by Michael Hickman on 28.11.23

www.hlem.co.za

www.ecoman.co.za

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