This is a very different dendrobium to yesterday’s Dendrobium deicatum and a species that is a guaranteed show stopper with its long pendulous pseudobulbs and large, dramatic and fragrant flowers.
As you can see from the first photograph the plant is a whopper with pseudobulbs 2m long with over a metre producing flowers in groups of two or three.
Dendrobium wardianum comes from the Eastern Himalayas from Assam through to Vietnam where it is found from 1000 to 2000m and so experiences a monsoon climate with a warm wet summer and a cooler dryer winter. It is deciduous and needs a cooler dryer winter rest to lose its leaves from the previous year’s growth and then flower from the bare pseudobulb.
The flowers have that delightful dipped in pink ink tip to the petals and sepals as well as a lot of yellow in the lip which distinguishes it from the similar looking Dendrobium nobile. Dendrobium nobile also differs in flowering from pseudobulbs produced two years ago not the most recent ones like this species. Dendrobium nobile and Dendrobium wardianum form the basis of a large group of hybrids.
We grow the plant in our Warm Asia section where it always produces the new growth (at the top of the first photo) before flowering so we don’t give the plant a completely dry rest
Today’s spring sunshine warmed up the greenhouse and filled it with the heady fragrance of Dendrobium delicatum.
Dendrobium delicatum is a natural hybrid between two Australian species, that have already featured in 365 days, Dendrobium speciosum and Dendrobium kingianum . With the variable nature of the parent species it is not a surprise that Dendrobium delicatum is highly variable too.
The plant above is our clone ‘pink blush’ but we have other clones that are white and cream but all are very fragrant. The plants are variable too but generally have long pseudobulbs (up to 40cm long) which are much thinner than those on Dendrobium speciosum.
The plant makes a great specimen as it gets older and the top photo shows ‘pink blush’ over 1m across, but our largest plant is a whiter clone that is more than 2m across (below) just coming into flower.
When fully out the leaves will hardly be visible and it won best specimen at the RHS London Orchid Show in 2019 (see below) but will be even better this year when all its flowers open. The species is also easy to grow and quick to propagate from keikis.
We grow plants in our Cool Asia section (min 10C) and in our Temperate section (min 6C) so this is a cool growing species although plants that have found their way into other sections of the greenhouse also flourish. We keep plant well watered in the summer when in growth but a bit dryer in the winter and spring especially when in flower.
We have been busy in the greenhouse this week during lunchtimes and after school especially repotting plants such as these Stenoglottis fimbriatas and pollinating flowers to produce new seed for the propagation laboratory.
During lessons the Year 13 science students have been continuing their work linked to our partner scientists at Kew with CTAB DNA extraction in the fume cupboard ready for next week’s PCR.
Another miniature orchid with a big character is this delicate and graceful species of Bulbophyllum. Bulbophyllum auricomum is the national flower of Myanmar and features in traditional songs and literature as well as in buddhist traditions. Its name refers to its golden lip and as the plants grow high in the tree tops the flowers represent purity.
We first came across the species when asked to grow it from seed by a local Buddhist centre where they grew the species in the traditional way on coir matting. We found that the species is easy from seed in-vitro and can even flower in jars.
The species comes from seasonally dry lowland forests and drops its twin leaves in the winter. We find that it needs a dry bright winter (we put our plants up high out of the reach of most of our waterings) or it doesn’t flower and is liable to rot, but the particular requirements of the species are worth the effort for these lovely fragrant flowers. During the summer we water heavily to encourage large bulbs for good flowering and the species spends all year in our Warm Asia section high
We have just been sent these photographs by BBC time-lapse specialist Tim Shepherd of our Gongora tracyana in the camera lenses for the BBC’s forthcoming Green Planet series. We cant wait to see the finished film.
Gongora truncata is a really lovely plant with masses of small flowers on long spikes. The flowers are fragrant and seem relatively long lasting (just over a week). The species is native to wet lowland forests in Panama and South America.
Time will be back at school in a week or so to work with students to select some more species to feature in the series.