Geography and distribution
Native to Colombia, Caliphruria tenera is known only from two specimens collected there over 150 years ago. One specimen was collected in the Rio Magdalena valley (‘noted as ‘Rio Luo’ on the specimen label) and the other in ‘Cundinamarca? Prov. Bogota, Copo la Parada’. It is known to have occurred at 400 m above sea level.
Herbarium specimen collected by Goudot in Colombia in 1844.
Overview: Caliphruria tenera is a small, bulbous, perennial herb. The bulb is spherical or ellipsoid, and about 25 mm in diameter, or 30 mm x 17.5 mm. The tunic (coat around bulb) is greyish-brown or tan.
Leaves: The leaves are hysteranthous (do not develop until after flowering).
Flowers: The slender scape (leafless flower stalk) is 16-27 cm tall and 1-2 mm in diameter. Each plant bears 5-10 white, 17-19 mm long funnel shaped flowers on long, thin pedicels. The stamens (male parts) each consist of two long teeth with a shorter, free filament inserted between them. The style (female part) has a 3-lobed stigma and the ovary is spherical.
Fruits: The fruits and seeds are unknown.
Threats and conservation
Large-scale deforestation is a threat to other Caliphruria species, which are unable to tolerate the higher light intensity in cleared areas. After the primary forest has been cleared the bulbs persist for a few seasons, but when the leaves develop without the protective shade of the forest canopy they show chlorosis and die back. However, so little is known about C. tenera as an individual species, that it is impossible to be certain of the precise factors that led to its demise. However, the fact that its leaves do not develop until after flowering has occurred, suggests it may have inhabited drier environments than the other species of Caliphruria.
Conservation assessments carried out at Kew
Caliphruria tenera is being monitored as part of the IUCN Sampled Red List Index for Plants, which aims to produce conservation assessments for a representative sample of the world’s plant species. This information will then be used to monitor trends in extinction risk and help focus conservation efforts where they are needed most.
C. tenera is rated as Critically Endangered and is considered Possibly Extinct. It will continue to be monitored as part of the project until Extinct status can be confirmed, at which point it will be removed from the list and replaced with a new species.
There is no information available on any previous uses of Caliphruria tenera. Other Caliphruria species, such as C. subedentata, are prized for their highly ornamental dark, glossy foliage. Bulbs of the closely-related genus Eucharis are collected by lowland native people in Central and South America for use in poultices, the bulbs being mashed, heated and applied to sores and tumours.
This species at Kew
The pressed and dried specimen (seen in the image, above) collected by the French explorer Justin Goudot in 1844 in Colombia and used by Kew botanist John Gilbert Baker when naming the species in 1888, is held in the Herbarium at Kew.
The image and details of this type specimen can be seen online in the Herbarium Catalogue. The specimen is part of the Herbarium Hookerianum (1867), which contains preserved plant specimens from the formerly private collections of William and Joseph Hooker now incorporated in the Herbarium.