Gastrochilus retrocallus is a species of miniature, epiphytic orchid that originates from the Ren-ai Township, Nantou County, in Taiwan. Inside this precious, beautiful nature reserve, Gastrochilus retrocallus can be found growing on trees in areas of cloud forests. This particular area is very rich in flora and fauna; there are many other special plants that originate from this area, including other orchids such as Cymbidiums.
Gastrochilus retrocallus used to be known as Haraella retrocalla.
Gastrochilus retrocallus is an incredibly floriferous orchid, plants grown in optimum conditions can almost always be in bud or flower. Gastrochilus retrocallus produces large, acidic yellow flowers with prominent maroon markings. The lower part of the flower has a soft, pliable texture and an almost wooly appearance and feel. I have included a photograph below that shows a British five pence piece held alongside the plant, to give you an idea of the diminutive size of this orchid and its blooms.
The blooms of Gastrochilus retrocallus release a light, citrus fragrance. The fragrance produced can vary from plant to plant, but I would say that the over riding scent notes produced by my plants are of citrus, it’s quite a lemony scent. Although, I do have one Gastrochilus retrocallus plant, which produces a fragrance, which to me is reminiscent of wax crayons! It’s a light scent, as is the fragrance produced by each of these plants. The fragrance of Gastrochilus retrocallus inflorescences maybe more powerful when the plant is grown under brighter lights, but I would not describe this orchid has one that produces a strong fragrance, my plants’ flowers produce a light scent.
In this miniature orchid’s native environment, in the cloud forests of the Ruei-yan river wildlife habitat in Taiwan, Gastrochilus retrocallus is pollinated by a particular species of beetle. The fragrance that Gastrochilus retrocallus blooms produce mimics the scent pheromones released by the female beetle of the plant’s pollinating species. The colouration and markings of Gastrochilus retrocallus‘ inflorescences have evolved to provide enough of a resemblance to the female beetle, that this visual resemblance, together with the flower’s scent, entices the male beetle, who believing he has found a receptive female, attempts to mate with the flower. After an unsuccessful mating attempt, the male beetle, who now unwittingly carries pollen with him, moves on, mistaking other blooms in the vicinity for female beetles, thus pollinating the Gastrochilus retrocallus blooms in that area.
I have a number of Gastrochilus retrocallus plants. I have found that this miniature epiphytic orchid grows best when it’s mounted on a cork or other tree bark, with flat moss positioned over the cork, before the orchid is placed onto the moss on the bark, so that the moss is behind the plant’s roots, and additional moss is placed over the plant’s roots as the plant is mounted. This covering of moss ensures that the moisture around the orchid’s roots is retained for longer, so the plant’s roots are less likely to entirely dry out. For more information on how to mount epiphytic orchids on to cork or tree bark, please click here.
I have a few Gastrochilus retrocallus plants growing inside my Orchidarium, where they are misted once a day, for 45 seconds in the early morning. This Orchidarium provides 75-85% RH, creating a humid environment for the plants inside. The plants receive quite bright light, and grow in temperatures that usually range from 16C to 22C. You can see the lighting, misting unit, and more information about my Orchidarium, by clicking here.
You may be interested in some of the trials I have conducted.
Terrarium, Vivarium, and Orchidarium Trials
To see how my Rainforest Terrarium was set up and to learn about the thinking behind my design, please click here.
To see a list of mini miniature orchids to grow inside terrariums or bottle gardens, please click here.
To see how my Orchidarium was created, please click here.
To read the first part of my White Orchid BiOrbAir Terrarium Trial, please click here.
To read the first part of my Madagascar BiOrbAir Terrarium Trial, please click here.
To read the first part of my Miniature Orchid BiOrbAir Terrarium Trial, please click here.
To read about the general care I give to my orchids and terrarium plants, and the general maintenance I give to my BiOrbAir terrariums, please click here.
To read how I track the temperature, humidity, and light conditions inside my terrariums, please click here.
Compost Trial Reports
To see all of my various Compost Trials, please click here.
To read advice on planting up containers, please click here.
Sweet Pea Trial Reports
To read the results of my 2017 Sweet Pea Trial, please click here.
To read the results of my 2016 Sweet Pea Trial, please click here.
To read the results of my 2015 Sweet Pea Trial, please click here.
Scented Daffodil Trial Reports
To read the results of my 2018 Scented Daffodil Trial, please click here.
To read the results of my 2018 Scented Daffodil Container Trial, please click here.
To read the results of my 2017 Scented Daffodil Trial, please click here.
Other articles that may interest you……………
To see a planting list of terrarium plants, including ferns, orchids and other plants that thrive when grown inside a terrarium, vivarium or other indoor garden, please click here.
To read about Aerangis luteo-alba var. rhodosticta, please click here.