''Geissoloma'' is a genus of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s in the
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...
family Geissolomataceae, native to the
Cape Province
The Province of the Cape of Good Hope (), commonly referred to as the Cape Province () and colloquially as The Cape (), was a province in the Union of South Africa and subsequently the Republic of South Africa. It encompassed the old Cape Co ...
of
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
.
''Geissoloma marginatum'' is the only species in the family.
It is sometimes called guyalone in English. The plants are
xerophytic
A xerophyte () is a species of plant that has adaptations to survive in an environment with little liquid water. Examples of xerophytes include cactus, cacti, pineapple and some gymnosperm plants. The morphology (biology), morphology and physiology ...
evergreen shrubs and are known to accumulate
aluminum
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
.
Description
''Geissoloma marginatum'' is a low evergreen shrub of ½-1¼ m high, covered in overlapping large, leathery, simple, scale-like, opposite leaves in four rows along the stems. It has very small stipules on the petioles. Flowers are bisexual, subtended by bracts, and have four red to pinkish petaloid sepals, four petals partially united, eight stamens, and four carpels. The fruit is a capsule with four seeds.
Phylogeny
Recent phylogenetic analysis resulted in the following tree.
References
Monotypic rosid genera
Endemic flora of the Cape Provinces
Crossosomatales
{{Rosid-stub