Description
(syn. Zephyranthes caerulea)
Habranthus caeruleus is a very little-seen species and though the name might imply a blue-flowered plant, this is really only true when the plant is in bud or when the flowers first open (our pictures, taken here, are not coloured or adjusted in any way, so you can get an accurate idea of their shade, as they open).
The colour is unique and very distinct in the genus and it veers distinctly towards blue in its overall colouring at all stages of its development, rather than the pink so often seen in Habranthus . Fascinatingly, it has an almost turquoise blue flash on the exterior of the outer three petals. The throat of the flower is green. With increasing age the flowers become pale lavender however the colouring dries to blue on a herbarium sheet, hence the botanical name.
The flowers, borne very late in summer and into autumn, are smaller when compared to some of the large species in the genus, however the colouring is unique and beautiful. The very narrow foliage follows the flowers and all of the growth springs from bulbs which are naturally very small.
In common with all Habranthus, this will not be hardy in the UK and it seems that it appreciates warmth when in growth as it grows on a Mediterranean cycle, being wintergreen and summer dormant, thus absolute freedom from frost is essential. Ironically although it is summer-dormant, it hails from a region which does get summer rains but it responds to extra water and a fall in temperatures, by flowering, much in the same way that Colchicum responds to the same conditions.
In the wild Habranthus caeruleus, which was described as long ago as 1877 by Lorenz, grows in the northeast of Argentina (it was discovered and described from near the city of Concepción del Uruguay) and reputedly also in Matto Grosso, Brazil where it was found in 1968. In the wild it occurs in well-drained, acidic soils in full sun. In cultivation, it grows perfectly satisfactorily in a well-drained, loam-based compost and ours is based on a John Innes and is slightly limey. It sets fertile seed with its own pollen, though seed set is never heavy.
