These delicate looking but long lasting flowers belong to Dendrobium aduncum and are produced over several months. The species comes from the Himalayas and South East Asia where it is found in forests from 300m to 1300m which indicates a tolerance of a range of temperatures, but we grow in in our Warm Asia section.
The species produces generous sprays of flowers along old leafless pseudobulbs.
Yesterday I talked about spring flowering orchids but today’s species is summer flowerer. Sobralia macrantha usually unfurls its first gigantic flowers in May (so is a week early this year) and will flowers on and off until the end of July.
Sobralia macrantha is found from Mexico to Costa Rica where it grows as a terrestrial in leaf litter, and its massive flowers are matched by the plant with thin canes that grow to a height of around 1.5m with alternate dark green tough leaves. The terminal flowers open successively over a period of several weeks. The flowers are fragrant but only last two to three days.
The lip of flowers have a charming creased look from being all folded up in the bud but when fully open the flowers a about 20cm across and 25cm from top to bottom.
We grow our plants in pots of bark and moss to replicate the natural habitat in Central America and keep plants watered all year in our Warm Americas section where plants get a minimum if 15C and bright light.
Issy looks after this genus and calls Sobralia Macrantha, Samantha (obviously). Two years ago Issy pollinated Samantha and sowed the seed in our propagation lab where we now have several hundred of these marvellous orchids nearly ready to come out of flask.
Hannah and Issy with Samantha the Sobrailia macrantha and her first flowers of the summer in May 2018.
You may have noticed that we have had a fantastic array of lovely species flowering this spring and we are still in the main flowering period for the orchid collection – A question we are often asked is ‘why do so many species flower in the spring?’
Many of the orchid habitats we have visited (especially the Himalayas, South East Asia, Brazil and Central America) have a strongly seasonal climate with the general rule for tropical forests, away from the equator, being cooler dryer winters and warmer wetter summers. In this seasonal climate the best time for orchids to be putting resources into developing seed and seed pods is during the wet warm summers, and so the best time to flower is just before the warm wet summer, at the end of the dry season – so spring.
One species that flowers just before the wet season is this gorgeous Dendrobium that we have seen growing abundantly in southern Laos.
Dendrobium chrysotoxum is native to seasonally dry forest monsoon forests and we found it in several locations at around 1000m around Paksong on the Bolaven Plateau. Plants were mostly growing on the trunk and lower branches of large trees in good light as shown on the photo below.
In cultivation we reflect the natural habitat by growing plants warm and wet in the summer in Warm Asia but give a cooler and much dryer winter in the top of Cool Americas. We find that baskets are ideal for this rewarding species.
Our greenhouse is once again full of the pungent spicy aroma of this wonderful orchid that flowers in profusion from leafless bulbs every spring.
Lycaste aromatica is native to Mexico and Central America where it grows as an epiphyte of lithophyte in semi-deciduous forest. It uses its powerful scent to attract euglossine bees (perfume gathering bees) and in common with many plants adopting this strategy has fairly short lived flowers (a couple of weeks).
The native habitat experiences a marked dry season and so the species drops all its leaves in November and remains leafless until April or May. We reduce watering to almost none while there are no leaves but in the summer once growth is underway we water heavily to support the rapidly growing lush leaves.
It suits our temperatures in Warm Americas with a winter minimum of 15C