Biology
(
anglais
)
fourni par Arkive
Lichens are remarkable organisms; they are stable combinations of an alga and/ or a cyanobacteria with a fungus, living together in a symbiotic association (2). The fungus causes the alga to release sugars, which allow the fungus to grow, reproduce and generally survive. The fungus provides protection for the alga, and enables it to live in environments in which it could not survive without the fungal partner (2). A general rule is that the fungal component of a lichen is unable to live independently, but the alga may live without the fungus as a distinct species (6). Many lichens are known to be very sensitive to environmental pollution; they have been used as 'indicators' of pollution (5) and are extremely slow-growing (9).
Conservation
(
anglais
)
fourni par Arkive
At present there is no conservation action being undertaken for this British Red Data Book Species.
Description
(
anglais
)
fourni par Arkive
Francis' lichen is a yellowish-green scattered crust, and the fruits are orange-brown but have never been recorded in Britain (8). The algal partner is Trentepohlia sp. (2). The Zamenhofia genus of lichens is named after the inventor of the Esperanto language, Ludwig Zamenhof (2).
Habitat
(
anglais
)
fourni par Arkive
Occurs on old trees, particularly oak (Quercus species) in ancient forests (4).
Range
(
anglais
)
fourni par Arkive
Very rare in Britain, Francis' lichen occurs in the south of England, but is most frequent in the New Forest (2). Elsewhere the species occurs in France, Spain and Madeira (4).
Status
(
anglais
)
fourni par Arkive
Classified as Near Threatened in Great Britain (3).
Threats
(
anglais
)
fourni par Arkive
Whilst no immediate threats are apparent, it seems likely that this lichen is sensitive to the loss of old trees and unsuitable woodland management (7).