Galtonia

Galtonia candicans at Colesbourne Park

A friend recently asked me how to tell apart the different species of Galtonia, a South African genus of four species in the Hyacinthaceae, closely related to and sometimes included in Ornithogalum. Of these, G. princeps is extremely rare in cultivation, and can effectively be knocked off the list of possibilities. The most familiar by far is Galtonia candicans, with abundant, large, pure white flowers: a magnificent hardy bulb for the summer garden. It needs to be seen en masse for its quality to be appreciated, and I have never seen it better than yesterday at the Savill Garden, where it fills all the gaps between big clumps of Agapanthus in a wide border. The effect is magnificent. G. candicans is native to eastern South Africa, at mid-altitudes (1350-2150 m), higher than the less hardy G. princeps, in which the flowers are less pure white, having a green band on each of the segments.

Galtonia candicans and Agapanthus at the Savill Garden

Galtonia regalis

G. regalis

 The other two species both have green flowers, but are easily distinguished. Both are from the Drakensberg, but whereas G. viridiflora has quite a wide distribution in the drier areas of the Eastern Cape and Lesotho, G. regalis has a narrow range on the wet, east-facing escarpment of the Berg in the area where Kwa-Zulu Natal meets the Free State and Lesotho, centred on Mont-aux-Sources. Its specific epithet, regalis, records its discovery in the Royal Natal National Park, where it is common on the cliffs of the Sentinel and Amphitheatre. To my mind it is the more attractive of the two, being shorter in stature and having more open flowers of a soft pale creamy green. The foliage is shining bright green, and tends to arch outwards.

G. viridiflora

The flowering times overlap, but G. viridiflora starts a week or 10 days earlier than G. regalis, but the flowers do not open widely and form a rather narrow tube of darker green with a hint of glaucous wax. They're also more numerous and more closely-spaced, and held on a much taller inflorescence. The leaves are more stiffly upright, and are also somewhat glaucous. It doesn't stand out in the garden as well as G. regalis does, but both are quite subtle in their charms and effect, so it's not surprising that the showy G. candicans is by far the best known member of the genus. All are easily grown from seed sown in spring, and these three at least are hardy in Britain.

The rather tubular, clustered flowers of Galtonia viridiflora

The genus commemorates the polymath Sir Francis Galton (1822-1911), a noted traveller in his youth (and author of The Art of Travel, a wonderful insight into Victorian travel), but he does not seem to have visited anywhere that Galtonia would grow naturally. He quickly accepted his cousin Charles Darwin's views on evolution, and investigated heritability and variation in human character (especially intelligence) and morphology (pioneering the use of fingerprinting in criminology, for example), advocating eugenic marriages for the production of brighter children.

Francis Galton in the 1850s (Wikicommons)