Blood on the rocks

The local endemic Gladiolus cruentus

and the history of the muddling of its name

Every now and again our understanding of what constitutes and defines a particular species is spectacularly misinterpreted by botanists in their various writings. One of our local Krantzkloof specials, Gladiolus cruentus, is just one such example of how confusion can reign for over a century, stemming, as Olive Hilliard & Bill Burtt put it ‘’from the attempt to squeeze three species into two’’. Their 1983 account of the relationship of G. cruentus to two other red-flowering gladioli in KZN has thankfully succeeded in clarifying the situation, as it showed that the names of G. saundersii and G. flanaganii should not be applied to plants found growing on moist cliffs of the Natal Group Sandstones close to the coast at elevations of 400-900 m, which should rather be called G. cruentus.

Gladiolus flanaganii is a high altitude endemic of the Drakensberg escarpment, occurring on basalt cliff faces from Sani Pass northwards to Mont-aux-Sources, whereas G. saundersii occurs from Joubert’s Pass in the Eastern Cape through Lesotho to the northeastern Free State, again at high elevations. Although an inhabitant of rocky places, this latter species is not a cliff-dwelling specialist (cremnophyte) but is rather considered terrestrial.

As for which species were squeezed into two makes for a long and convoluted story, as some Victorian-era botanists such as Medley Wood and Baker were conflating saundersii and cruentus, as did Pole-Evans in his account of 1925, whilst others in the mid- to late-20th century such as Lewis & Obermeyer were later equating flanaganii with cruentus. As a result of the confusion generated we find a variety of misapplied names provided in the popular literature available to us: in their Drakensberg wildflower books both Reg Pearse and William Trauseld labelled their photographs of G. flanaganii as G. cruentus whilst Janet Gibson in her coastal wildflower volume labelled her painting of G. cruentus as G. saundersii. At any rate, the species boundaries are (seemingly!) resolved, and we know now which names to apply to what plants from where, such that in both the more recent field guides by Elsa Pooley (Field Guide to Wildflowers and Mountain Flowers) the correct names have been applied to all three species. We seem at last to be on the right track…

Plants of Gladiolus cruentus grow with their corms braced in the fissures of the sandstone cliffs, producing soft, floppy sword-shaped leaves that droop downwards. They are most noticeable in flower between January and March when producing their spikes of up to nine large blood-red flowers. These inflorescences are inclined and drooping, and reach a length of about 70 cm.

The upper three lobes of the open-faced flowers of G. cruentus are typically without markings, but the lower three are usually marked with white. The distribution of these markings are quite variable, with sometimes only the lower two lateral tepals showing an irregular banding of creamy white, and mottling toward their base. In the flower shown here, all three lower tepals are clearly marked with white. It is likely that the white markings act as nectar guides for its pollinator, which has been assumed by some to be the Mountain Pride butterfly, Aeroptes tulbaghia. However, this particular satyrid is not documented as occurring within the range of distribution of G. cruentus and is most unlikely then to be involved. So keep an eye out for any floral visitors and become the first to work out which pollinator is responsible!

Although only small clumps of Blood-red Gladiolus are usually encountered, it can sometimes be seen in quite large colonies, as here on a southern aspect at Table Mountain near Pietermaritzburg. Plants are hard to reach and photograph, particularly as their preferred sandstone cliff habitat is along slippery seasonal drip lines, or in the spray of waterfalls. Its cliffside cohabitants at this spot accordingly included Begonia sutherlandii and Selaginella mittennii, as well as Drimia flagellaris, a locally endemic bulb first described in 2005 from Krantzkloof Nature Reserve. Gladiolus cruentus is itself a narrow endemic, found mainly in the Valley of a Thousand Hills region. It is essentially restricted to the Umgeni river system, from near Pietermaritzburg and the Little Noodsberg through to Kloof, Pinetown, Inanda, Umbumbulu and Kranskop.

The late Rod Saunders, photographed by the author in Krantzkloof Nature Reserve on 28 February 2015. He and his late wife Rachel were taken there by the author especially to photograph Gladiolus cruentus for their field guide to the gladioli of South Africa, in which volume (p. 105) this very plant is illustrated. In acknowledgement of the importance of their unfinished project the field guide was posthumously completed by Fiona Ross, and published by Struik Nature.

Blood on the rocks: short of being red-green colour blind one can hardly but notice this colourful splash of red on the cliff alongside the Molweni River below the Krantzkloof Falls. Although often seen growing in close proximity to shady forested areas, the plants require access to bright sunlight and so occur where there are permanent openings in the canopy. This in part reflects their need to accommodate their pollinator, whatever that turns out to be.

As reflected on in the Saunders’ Field Guide to Gladioli of South Africa, ‘’the seeds seem to fall from one ledge to the next and subsequently germinate in the rock cracks’’. Many such cliff dwelling plants of this species become then ‘’accessible only to mountaineers’’ as aptly noted by Janet Gibson. In consequence, although listed as Critically Endangered and accordingly at high risk of extinction, their collection for any purpose is usually very difficult. The plants at remaining sites do though still face indirect threats through competition with plant invaders and due to water extraction, given their need for seasonally wet habitat. It has been assessed that all the remaining subpopulations of G. cruentus would fit within an area of only about 10 hectares, to give one an idea of how rare these sites collectively are.

The name ‘cruentus’ means blood-stained, in obvious reference to the colour of the flowers, hence its common name of ‘Blood-red Gladiolus’. This stunning species has been taken into horticulture, and in fact was first described from material sent from South Africa to the nursery of one Mr Bull of Chelsea, London. Thomas Moore, who introduced the species to science and horticulture in The Gardener’s Chronicle and Agricultural Gazette of 1868, noted it to be ‘’…a grand acquisition for the flower garden…it will probably be of great value to the hybridizer, and will doubtless impart some novelty of feature to the popular varieties of this favourite flower.’’

References

Baker, J.G. 1896. 61. G. cruentus. Flora capensis 6: 157.

Edwards, T.J., Crouch, N.R. & Styles, D. 2005. Drimia flagellaris (Hyacinthaceae), a new discovery from KwaZulu-Natal. South African Journal of Botany 71(1): 122-126.

Gibson, J.M. 1975. Wild Flowers of Natal (Coastal Region). The Trustees of the Natal Publishing Trust Fund, Durban.

Hilliard, O.M. & Burtt, B.L. 1983. Notes on some plants of southern Africa chiefly from Natal: X. Notes of the Royal Botanic Gardens Edinburgh 41(2): 299-319.

Lewis, G.J. & Obermeyer, A.A. 1972. Gladiolus: A revision of the South African Species. Purnell & Sons, Cape Town.

Moore, T. 1868. New Plants. Gladiolus cruentus, Moore, sp. n. The Gardener’s Chronicle and Agricultural Gazette 1868(1): 1139.

Pearse, R.O. 1978. Mountain splendour. Wildflowers of the Drakensberg. Howard Timmins, Cape Town.

Pole-Evans, I.B. 1925. Gladiolus cruentus. The Flowering Plants of South Africa V: Plate 182.

Pooley, E. 1998. A Field Guide to Wild Flowers KwaZulu-Natal and the Eastern Region. Natal Flora Publications Trust, Durban.

Pooley, E. 2003. Mountain Flowers. A Field Guide to the Flora of the Drakensberg and Lesotho. The Flora Publications Trust, Durban.

Saunders, R. & Saunders, R. 2021. Saunders’ Field Guide to Gladioli of South Africa. Struik Nature, Cape Town.

Trauselt, W.R. 1969. Wild Flowers of the Natal Drakensberg, Purnell & Sons, Cape Town.

Wood, J.M. 1904. Natal Plants. Gladiolus saundersii, Hook. Vol. IV, Part II. Plate 342, Bennett & Davis, Durban.

About the author

Neil Crouch, a Kloof resident, has a Ph.D in botany from the University of Natal and works in the biodiversity economy field. He has authored numerous scientific papers and articles and co-authored Field Guide to Succulents in Southern Africa, and Ferns of Southern Africa: A comprehensive guide, both published by Struik Nature.