Spiranthes cernua var. odorata ?Chadd?s Ford?
The Genus Spiranthes is widely dispersed with over 300 species worldwide, and includes many sections. Section Spiranthes consists of the white ladies?tresses familiar to many of us and was given this name in the distant past after the resemblance to plaited hair. William Turner in an English Herbal of 1548 referred to S.spiralis as ?Lady traces?. That said, the majority of the group center geographically in the Eastern United States where S.cernua is noted for its ability to adapt to many differing environments and presents itself differently according to the set of genes employed. ?Chadd?s Ford? is available quite widely in the UK and was named after the home of Dr Brubecker near Philadelphia, Pennsylvania from where it was introduced into the trade in 1973 and has been reproduced in vast quantities by tissue culture.
It is an easy orchid in the UK and survives well in the open garden provided a fairly wet but not waterlogged environment can be provided. It can reach a height of 30? or more (75 cm) with a thin stem of up to 70 fragrant(vanilla), sparkling white, almost translucent flowers, the base of the flower is arched prominently downward, giving it a nodding posture and resulting in the specific name, cernua meaning ?nodding?.
The flower spike is surprisingly resistant to the sort of buffeting it can receive when in bloom, October-November. The basal rosette of linear leaves is in growth most of the year although is barely retained around flowering time. The roots are stoloniferous and last for more than one growing season(usually 3-4) and so slowly build up into a cluster of rather long, brittle, carrot like structures, and as these mainly descend vertically, they appreciate a deep pot. Like Dactylorhiza, if grown in pots sat in a tray of water the roots will sit just above, rather than in the water although they relish the constant damp. Spiranthes carry a permanent culture of fungus in their roots and this should never be allowed to dry out as it has a large part to play in feeding the orchid. Only one or occasionally two new roots are formed each year. When repotting, be sure to use a suitable organic compost and water in thoroughly when complete.
In pots I use equal quantities, JI no 3, crushed grit(4-6mm), a multipurpose humous rich compost and sieved beech/oak leafmould. This is replaced every second year. I am informed that it will volunteer seedlings in and around the pot which grow on to flower in their second year though I have never seen these myself. With access to constant moisture they will take full sun though they are undoubtedly happier in light shade.
In the wild S.odorata which has now become S.cernua var. odorata grows at the North East extent of the range of S.cernua and is usually more vigerous and prefers a wetter environment. Seen together, S.odorata will be in flower at the bottom of the ditch while S.cernua occupies the space on the sides of the ditch. These are both common roadside plants and as such are subjected to periodic mowing, fortunately their basal rosette and late flowering allows them to persist in this regime where they compete quite happily with the rest of the vegetation. These last two pictures taken in late October in the Blue Ridge Parkway, Applachian Mountains, North Carolina and show how the plants can appear in significant quantities.
These particular sites were hillsides (one shallow, one steep), that receive morning sunlight only, where the soil was always damp but where excess water ran off easily. Both sites are constantly visited by Bumble bees.
Photographs in the wild by kind permission of Jim Fowler, Native Orchid Conference USA and author of ?Wild Orchids of South Carolina?.