Wednesday, November 16, 2011

The Hydrangea Orchid: Cynorkis purpurascens or C. uncinata or C. calanthoides

This orchid seems to be suffering from taxonomic woes at the current time, and while I can't be exactly sure of the scientific name (purchased from Andy's Orchids as C. purpurascens or C uncinata, they also appeared unsure of the exact identity), I have coined a novel common name which I like quite well.

The Hydrangea orchid, yes, how fitting.  And here's why, each year this rarely grown terrestrial orchid emerges from dormancy and undergoes a miraculous transformation that attracts droves of  attention (well it would if on display at a public garden).  Putting to shame those orchids that require close inspection in order to be appreciated, this stunning species puts on a riotous hydrangea-esque floral display over a lengthy 4-month period, lasting from summer into late autumn .  The plants goes dormant in late winter and as temperatures rise and the day length increases, it begins to produce fleshy, bright green tongue-like leaves that continue to grow.  As the leaves expand in size the plant slowly comes into flower, and at first it may seem a somewhat disappointing (or, in the words of my friend Russell, "You lied to me, because I really thought that plant was going to be better."),  but as the summer progresses each inflorescence on a large plant will develop into a 20 cm diameter globe studded dozens of 1 inch diameter lavender purple flowers.   At peak flowering, the leaves are fully expanded and can be as much as 60 cm in length, providing the perfect foil for the floral display.

Another curious feature of this plant is the blue pollinium.  Cynorkis purpurascens is native to a large portion of the southern hemisphere.  This plant will seed seed when hand-pollinated and appears to tolerate self-pollination.  I have not looked at the seed under a microscope to assess the viability or sown any as one plant is quite enough. 

Cynorkis purpurascens is native to a Madagascar, South Africa, and some of the surrounding islands.  Like other orchids, this species appears to be quite morphologically variable (hence taxonomic confusion).

This plant is eay to grow.  It prefers hot, humid conditions in summer under partial shade with ample moieture.  As the days begin to shorten, the flowering comes to an end and growth ceases.  In mid-widwinter I stop watering the altogether.  The plant goes completely dormant, emerging only after temperatues and day-lengths increase in spring.