''Cladonia cayennensis'' is a species of
fruticose lichen in the family
Cladoniaceae.
It is found in
French Guiana, although the authors suggest that its distribution might be more widespread.
Taxonomy
The lichen was
formally described as a new species in 2013 by the lichenologists
Teuvo Ahti
Teuvo ("Ted") Tapio Ahti (born 1934) is a Finnish botanist and lichenologist. He has had a long career at the University of Helsinki that started in 1963, and then following his retirement in 1997, at the Botanical Museum of the Finnish Museum ...
and
Harrie Sipman
Henricus (Harrie) Johannes Maria Sipman (born 1945) is a Dutch lichenologist. He specialises in tropical and subtropical lichens, and has authored or co-authored more than 250 scientific publications. He was the curator of the lichen herbarium ...
. The
type specimen was collected by
André Aptroot
André Aptroot (Heemskerk, 1961) is a Dutch mycologist and lichenologist.
In 1993 he did his PhD at the University of Utrecht under the supervision of Robbert Gradstein (nl). His dissertation was titled "Systematic studies on pyrenocarpous li ...
from the
botanical garden in
Cayenne
Cayenne (; ; gcr, Kayenn) is the capital city of French Guiana, an overseas region and Overseas department, department of France located in South America. The city stands on a former island at the mouth of the Cayenne River on the Atlantic Oc ...
, where it was found growing on
palm.
Description
''Cladonia cayennensis'' is characterised by a durable , which is the main vegetative body of the lichen. This thallus comprises flat to slightly curved, scale-like segments known as , typically measuring 1–2 mm in width. These squamules are soft and delicate, with rounded edges that are either smooth or slightly divided. The upper surface of the squamules presents a greenish-brown colour, while the underside is white, with a fluffy or cotton-like appearance. This underside is loosely covered with
soredia, especially along the margins, giving it a somewhat powdery look. Soredia are vegetative
propagules present as small clusters of algal cells surrounded by fungal filaments, aiding in the lichen's reproduction and spread. In some instances, these squamules have short, brownish-veined stalks at their base. As for reproductive structures, ''Cladonia cayennensis'' lacks
podetia,
conidiomata, and hymenial .
In terms of chemistry, ''Cladonia cayennensis'' contains
usnic acid
Usnic acid is a naturally occurring dibenzofuran derivative found in several lichen species with the formula C18H16O7. It was first isolated by German scientist W. Knop in 1844 and first synthesized between 1933-1937 by Curd and Robertson. Usnic a ...
, albeit in low concentrations. Additionally, this species contains
zeorin
Zeorin is a triterpene with the molecular formula C30H52O2 which occurs in many lichens
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among hypha, filaments of multiple fungus, fungi species in a mutu ...
, which forms needle-like crystals that are particularly abundant in older
herbarium
A herbarium (plural: herbaria) is a collection of preserved plant specimens and associated data used for scientific study.
The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sheet of paper (called ...
specimens. The colour reactions of ''Cladonia cayennensis'' are negative for the standard lichen
spot tests, indicated as P–, K–, and KC–.
See also
*
List of ''Cladonia'' species
References
{{Taxonbar, from=Q80874792
cayennensis
Lichen species
Lichens described in 2013
Lichens of French Guiana
Taxa named by Teuvo Ahti
Taxa named by Harrie Sipman