Thursday, 20 November 2014

Arundina graminifolia

Arundina graminifolia [D Don] Hochr. 1910

Common Name: The Grass-Like Leaf Arundina - The Bamboo Orchid

Rhizome of Arundina graminifolia is used in extraction of certain anti-viral/anti-bacterial compounds. Flowers and stem extract is used in Chinese medicine as anti-cholesterol compound.

Distribution & Occurrence:

Many parts of south east Asia at various altitudes

The Plant

Giant sized (upto 2 meters) warm to hot growing terrestrial orchid with tall and thin stems like bamboo

Blooms throughout the year on a terminal inflorescence that carries 2 to 6 fragrant cattleya like flowers but flowers open one at a time. Flowers are short lived

Flower color and lip shapes are extremely variable

Cultural Requirements and Nutrition

Grow in bright light with atleast few hours of direct sunlight and medium should dry out soon. Water and fertilize all around the year

Though it is a terrestrial, it should be potted in a loose and fast draining medium. I grow in 50% charcoal and broken tiles 50%

Pest and Diseases

No specific pests or disease.

Hybrids

No registered hybrids

Bloomed in Oct 2014






Vanda tessellata

Vanda tessellata (Roxb.) Hook. 1850 SECTION Longicalcarata

Common Name: The Lattice-Like Paterned Flower Vanda

Juice of the compressed plant is used as a cure all drink in Malaysian peninsula. V. tessellata plants have been used in the indigenous medicine such as Ayurveda and local traditional medical practices. The leaf juice is used for the treatment of certain inflammatory conditions. It is also instilled into the ear as a remedy for otitis. The leaves paste is applied to the body to bring down fever. Root paste is applied to the affected area for the treatment of rheumatism. The root paste is also used in treatment of nervous problems, bronchitis, dyspepsia and fever. Unani practitioners hold it to be laxative and tonic to the liver. It is also used to treat hiccough, piles & boils in head.


Distribution & Occurrence:

Western Himalayas, Burma to south India & Srilanka @ elevations of 1200 to 3000 Meters.

The Plant

Medium to large sized warm to cold growing vandaceous epiphyte with climbing stems and semi terete leaves

Flowers around the year in summer, autumn and winter. Inflorescence carries 6-12 fragrant long-lived flowers. Flower shade and lip shade are very variable ranging from yellow to blue.

There is also a difference in flower size and bloom frequency, The North Indian varieties are the smallest but flower more frequently while the Sri Lankan varieties are bigger, of better form and some of them come in various shades of red and grey though they are not as floriferous as the North Indian ones. The South Indian ones are somewhere in between in terms of size and they do bloom quite often.

Vanda tessellata can be identified by it's fish bone pattern of leaf arrangement the side lobes on the lip have a very characteristic pointed curve which is not seen even in its first generation hybrids.


Cultural Requirements and Nutrition

Grow in moderate strong light with long hours of direct sunlight. Water and fertilize throughout the year.

Pest and Diseases

No specific pests or disease.

Hybrids

Vanda tessellata has been used extensively in hybridization, with Vanda Mimi Palmer a very striking lookalike being one of the most famous and V Cindy Banks and V Arjuna Wink being other famous hybrids

Bloomed in Oct 2014









Saturday, 25 October 2014

Shade Cloth for Orchids

Shade Cloth  -- Orchid house

Shade nets are useful in outdoor and greenhouses; they provide physical protection (birds, insects & excessive radiation) and help protect the plant from excessive heat radiation, sunburns and stress following the radiation.

There are two crucial parameters for shade net. One is the shading factor in % and another is color of shade net

Shading factor

Shade nets are available in various shading factors and higher the shading factor, shade net would block more radiation and would reduce the temperature of air, soil and plant inside the shade house.

Right shading factor for orchids is dependent on the location and elevation of the place. I am using a 50% shading factor cloth blocks 50% of the sunlight.

Recommend using a light meter (available standalone or built in in a camera or an iOS app) to decide whether the shade cloth is providing the right amount of light for the orchid you are growing. Measure the light at same location at various times of the day to decide the amount of sun light it is receiving and then decide on the amount of shade net

Amount of light depends on type of orchid. For e.g. Vanda’s require very high light, followed by Cattleya and dendrobium.


Genera
Foot Candles
Vanda
4000 to 6000 ft-candles
Oncidiums, Dendrobiums and Cattleyas
2000 to 4000 ft-candles
Some Paphs
1500 ft-candles


Color of Shade Net

Shade net is usually made out of UV resistant material and scatters most of the UV light. Shade net that scatters the most of the light but does not alter the spectrum of the light provides the best condition for growth.

Color of shade cloth is an important parameter that needs to be considered for Orchid house

Color
Light Scattering
Heat Generation
Full Spectrum of Colors
Comments
Silver color /Aluminum based
★★★★★
None
★★★★★
Best but not available in India
White
★★★★
None
★★★★★
2nd Best
Red
★★★
★★
★★★
Red light increases larger leaf surface, long and thicker stems and promotes early blooming

2nd Best
Black
None
★★★★★
★★★★
Produces more heat. Not suitable for normal temperatures but could be used in Winter to increase heating
Green
★★★
★★
★★
Green light is not useful to plants
Blue
★★★
★★
★★★
Blue light darkens the foliage and shortens the plant  & delays blooming


Black shade net can be used for growing only vanda genus and vanda’s thrive in black as they like the extra heat generation provided by black.

Oncidium Twinkle 'Red Fantasy' in Bloom


Oncidium Twinkle is a primary hybrid between Onc. cheirophorum x Onc. ornithorhynchum. emits the sweet scent of vanilla when blooming

Grow in partial shade in a semi hydrophonic medium.



Vanda coerulea

Vanda coerulea Griff. ex Lindl. 1847 SECTION Longicalcarata

Common Name: The Blue Vanda or Autumn Lady's Tresses

Ancient healers used the juice of the flower was by as eye drops against glaucoma, cataract and blindness. Active ingredients of Vanda coerulea are also used by modern pharmaceuticals to fight against the visible signs of ageing skin.

Vanda coerulea is endangered and is in CITES II

Distribution & Occurrence:

Western Himalayas to Thailand@ elevations of 800 to 1700 Meters.

The Plant

A medium to large sized warm to cool growing epiphyte found in deciduous forest with distinct dry season. Leaf span and Leaf arrangement of Vanda coerulea are different compared to other vanda species.

Vanda coerulea has a very short leaf, that is more or less horizontal and the leaf bracts are more visible and higher than other vanda.

Flowers once year during early or late fall and flower lasts a few months

Cultural Requirements and Nutrition

Vanda coerulea can tolerate more cooler conditions than most of the strap-leaf vandas and will be quite comfortable under intermediate temperatures, Requires strong light and heavy feeding during growth phases.


Pest and Diseases

No specific pests or disease.

Hybrids

Heavily used as pollen parent and seed parent

Bloomed in October 2014

Tips to identify Wild Form of Vanda coerulea

·       Vanda coerulea flowers tend to be somewhat taller than wide and never round
·       Wild and pure forms of Vanda coerulea, petals twist upto 180 degrees and never flat
·       Leaf arrangement is more horizontal and the leaf span is shorter
·       Side lobs of the lip has a sharp hook structure pointing towards the flower and this hook structure disappears after one cross
·       When the flower open started out as almost white and gradually increase their color.
·       On removing pollen from mature flower, and the flower should turn to complete white less than 24 hr. Most hybrids tend to retain the blue color a lot longer and wouldn't drastically noticeable until third day or so