An epiphytic or lithophytic orchid belonging to the Orchidaceae family is called Dendrobium bigibbum or Cooktown Orchid (Jones, 2006). The Pigeon Orchid, Albert Orchid, Stuberi Orchid, Emerald Orchid, Karawai Orchid, and Kelembai Orchid are all closely related to this orchid. The cylindrical pseudobulbs of Cooktown Orchid orchids have three to five green or purple leaves on each, as well as curved stems with about twenty purplish orchid flowers.
It is a medium to large, hot-growing epiphytic or lithophytic that can grow to a height of 40–122 cm. Its cylindrical, narrow, tapering slightly towards both ends, 40–122 cm tall, green or reddish-purple stems carry three to twelve ovate or lanceolate, acute, 8–15 cm long leaves held in the apical half.
- Dendrobium bigibbum var. bigibbum, also known as the light purple butterfly orchid, grows in the lowlands of the Cape York Peninsula, some of the Torres Strait Islands, and southern Papua New Guinea. It has a white spot in the center of the flower lip (labellum).
- Dendrobium bigibbum var. compactum, has a restricted range over a height of 250 meters in Queensland, Australia’s humid tropics (Brydie, nd).
- Dendrobium bigibbum var. schroederianum, also known as Dendrobium phalaenopsis, is a plant that only grows on Larat Island in the Maluku Islands and has a variety of flower colors.
Cooktown Orchid, a variety of Dendrobium bigibbum, has the largest flowers of the group but lacks a white spot in the center of the lip of the flower. In Queensland, Australia, on the slopes between Cooktown and Mount Molloy, this orchid is found.
The taxonomy of flowers from Dendrobium bigibbum orchids is as follows:
Sympodial and monopodial are the two distinct growth patterns of orchid flowers (Fitriyani, 2018). A flower with a monopodial growth pattern is the Dendrobium bigibbum orchid. Orchid flowers grow straight up on one stem, with a growing point at the end, and bloom from the side of the stem between the two leaf axils in this pattern of growth.
According to its morphology, the Dendrobium bigibbum orchid is a lithophytic or epiphytic plant with green or purple pseudobulbs that are 1.5–2 cm wide and 2–120 cm long. Three to five egg-shaped leaves, each 10-15 cm long and 3-3.5 cm wide, are present on each pseudobulb. Between two and twenty purple flowers are present on flower stems that are 20 to 40 cm long and grow in a curved direction. Pink or blueish Dendrobium bigibbum Orchids are extremely uncommon.
The size of the flowers varies by variety and ranges from 2-3 cm in length to 3-7 cm in width. The petals are 2-3 cm long, oval to egg-shaped, and 0.9-1.1 cm wide. The lateral petals are widely spaced apart, and the petal ridges are upright or back to back. Egg-shaped and measuring 2.5–3 cm long and wide, the petals. The flower’s three-lobed lip is 2-2.6 cm long and 2-2.8 cm wide. The central lobe has four or five ridges along its midline, the lateral lobes are upright, and the flower’s center is hairy. In bloom from February to July is this flower.
When there is insufficient light during the winter, Dendrobium bigibbum grows poorly and their buds droop. Because it needs a lot of light, hot winter temperatures, and a dry winter period—conditions that can be challenging to provide in mixed collections—this species is frequently regarded as being difficult to grow and flower.
The recommended light level for Dendrobium bigibbum is between 30.000 and 45.000 lux, with winter months having more light. For plants being grown, strong airflow and intense lighting are essential throughout the year.
Dendrobium bigibbum orchids should be left in the sun in the morning. Dendrobium bigibbum Orchid, however, needs to be moved to a more shady location that still receives sunlight when the sun is shining brightly and the air is getting hotter. These flowers can be grown on land that can be shaded with curtains.
The plant is thermophilic. Summertime temperatures typically range from 29 to 30 °C during the day and 22 °C at night, for a daily difference of 7-8 °C. Throughout the year, there is only a 2-degree difference in the daily amplitudes. With a daily difference of 7 °C, the average winter temperature is 24-26 °C during the day and 17-19 °C during the night.
The ideal temperature range for growing Dendrobium bigibbum orchids is 15 to 25 degrees Celsius. This plant can thrive in the wild at temperatures between 10 and 32 degrees Celsius.
For the majority of the year, the Two-Humped Dendrobium requires a humidity of about 70–75%. The humidity levels fall to about 65-70% at the end of winter and in the early spring.
Attached to pieces of tree fern or cork, Dendrobium bigibbum grows well, but in the summer it needs high humidity and daily watering. When it’s hot and dry outside in the summer, fogging should be done several times.
Medium-sized pieces of pine bark or cork should be used as substrates because they are very breathable and quickly permeable. Excellent drainage is required when growing plants in pots. It is preferable to use heavy clay pots because the plant has a high center of gravity.
Usually, pots that initially appear to be too small for these plants yield the best cultivation results. New pole-like pseudobulbs should be supported by supports.
Repotting should be done at the end of the plant’s flowering season or between the end of winter and the start of spring.
Summer and early autumn bring moderate to strong water, but winter brings drier conditions. The substrate of cultivated plants should be moist while they are actively growing, but as autumn approaches, watering should be gradually decreased.
This orchid doesn’t require a lot of water because it is always green. Watering it once every seven to nine days is sufficient. Only when the soil is nearly dry do these orchids require additional watering. A skewer can be used by cultivators to quickly determine whether the soil is dry or not. Place a skewer in the ground and periodically remove it. The Orchid Larat soil needs to be watered once more if the skewers are dry.
Every week, Dendrobium bigibbum should receive 1/4 to 1/2 of the fertilizer dosage advised for orchids. From early spring to mid-summer, a fertilizer with a high nitrogen content is beneficial, and late summer and autumn are the best times to use a phosphorus-rich fertilizer.
When planting and caring for Dendrobium bigibbum Orchid, cultivators need to be aware of a number of things. First, a coarse planting medium made of a combination of cypress wood, pieces of bark, perlite, and charcoal is best for growing this type of orchid. The planting medium can be changed out for a fresh one when it becomes loose or begins to rot.
Additionally, young Dendrobium bigibbum orchids require a lot of water. When they reach maturity, though, overwatering will actually cause them to wilt and rot. Cultivators can occasionally spray flower buds with a little water to keep them from drying out during dry seasons with low humidity.
The flowers from the Dendrobium bigibbum will naturally separate from the stem once the blooming season has passed. Dendrobium bigibbum orchid cultivators must wait eight to twelve months before they see new blooms.
Finally, a plastic or earthenware pot is the best kind of container for growing orchids. Dendrobium bigibbum orchids can be transferred to a larger pot if they have outgrown their current one. Moving the orchids to another pot won’t be a problem as long as they are healthy when they are planted. If the roots are soft or rotten, it is best to cut them out and replant the orchid in the same container.
When Dendrobium bigibbum has grown past the edge of the pot, you can also choose to slice or split it. The same-sized pot can hold two divided orchid flowers that can be planted separately.