Babiana socotrana
Encyclopedia
Cyanixia socotrana is a perennial, herbaceous
and bulbous plant
species in the Iridaceae
family endemic to Socotra
. The genus name is derived from the Greek
words Ixia, referring to the radially symmetrical flowers in the genus of that name, as well as cyanos, meaning "blue".
It was known until 2003 as Babiana socotrana. However, this species differs from all other members of the genus Babiana
in the shape and type of pollen grains, basic chromosome
number, x=10, corm
s globose and of axillary origin, and the morphology of the seed
s. For this reason was excluded from Babiana and referred to the new genus Cyanixia. Other Babiana species have a basic chromosome number of x=7, terminal corm ontogeny, and pear-shaped seeds.
Cyanixia socotrana was previously assigned to Babiana because of superficial similarities in morphology, including plicate leaves and blue flowers, thought at the time to be bilabiate, although now known to be actinomorphic and rotate. DNA sequence
analysis using the chloroplast
gene
matK confirms that Babiana is a monophyletic assemblage, whereas B. socotrana is sister to the Lapeirousia/Savannosiphon
clade
of sub-Saharan Africa. The latter shares axillary corm ontogeny, together with the southern African Micranthus
, Thereianthus
, and Watsonia
, in contrast to the more common situation in Crocoideae (including Babiana) in which the corm develops from the base of the flowering stem. The tropical African Zygotritonia
, which also has axillary corm development, shares with Cyanixia a trisulcate pollen grain, but it differs markedly from that genus
in its small, zygomorphic flower, undivided style, and basic chromosome number x=8. Cyanixia was described as a new monotypic genus of Crocoideae
, probably most closely allied to Savannosiphon
, also a genus with a single species.
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
and bulbous plant
Bulbous plant
In horticulture, a bulbous plant is an ornamental plant, herbaceous or perennial species which produce fleshly storage organs including true bulbs as well as corms, tubers, rhizomes, and tuberous roots...
species in the Iridaceae
Iridaceae
The Iris family or Iridaceae is a family of perennial, herbaceous and bulbous plants included in the monocot order Asparagales, taking its name from the genus Iris. Almost worldwide in distribution and one of the most important families in horticulture, it includes more than 2000 species...
family endemic to Socotra
Socotra
Socotra , also spelt Soqotra, is a small archipelago of four islands in the Indian Ocean. The largest island, also called Socotra, is about 95% of the landmass of the archipelago. It lies some east of the Horn of Africa and south of the Arabian Peninsula. The island is very isolated and through...
. The genus name is derived from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
words Ixia, referring to the radially symmetrical flowers in the genus of that name, as well as cyanos, meaning "blue".
It was known until 2003 as Babiana socotrana. However, this species differs from all other members of the genus Babiana
Babiana
Babiana Ker Gawler is a genus of flowering plants in the Family Iridaceae composed of about 80 species. Most of these species are found in the southwestern Cape of Africa, with the remainder distributed in Namaqualand and Northern Cape Province...
in the shape and type of pollen grains, basic chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
number, x=10, corm
Corm
A corm is a short, vertical, swollen underground plant stem that serves as a storage organ used by some plants to survive winter or other adverse conditions such as summer drought and heat ....
s globose and of axillary origin, and the morphology of the seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s. For this reason was excluded from Babiana and referred to the new genus Cyanixia. Other Babiana species have a basic chromosome number of x=7, terminal corm ontogeny, and pear-shaped seeds.
Cyanixia socotrana was previously assigned to Babiana because of superficial similarities in morphology, including plicate leaves and blue flowers, thought at the time to be bilabiate, although now known to be actinomorphic and rotate. DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
analysis using the chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
matK confirms that Babiana is a monophyletic assemblage, whereas B. socotrana is sister to the Lapeirousia/Savannosiphon
Savannosiphon
Savannosiphon is a genus of flowering plants in the family Iridaceae. The genus name, derived from the word savanna and the Greek word siphon alludes to its habitat and the structure of its perianth tube....
clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
of sub-Saharan Africa. The latter shares axillary corm ontogeny, together with the southern African Micranthus
Micranthus
Micranthus is a genus of flowering plants in the family Iridaceae. The genus name is derived from the Greek words micro, meaning "small", and anthos, meaning "flower"....
, Thereianthus
Thereianthus
Thereianthus is a genus of flowering plants in the family Iridaceae. The genus name is derived from the Greek words thereios, meaning "summer", and anthos, meaning "flower"....
, and Watsonia
Watsonia (plant)
Watsonia is a genus of plants in the iris family, subfamily Crocoideae, native to South Africa. The genus is named after Sir William Watson, an 18th century British botanist....
, in contrast to the more common situation in Crocoideae (including Babiana) in which the corm develops from the base of the flowering stem. The tropical African Zygotritonia
Zygotritonia
Zygotritonia is a genus of herbaceous, perennial and bulbous plants in the Iris family . It contains four species distributed in Tropical Africa...
, which also has axillary corm development, shares with Cyanixia a trisulcate pollen grain, but it differs markedly from that genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
in its small, zygomorphic flower, undivided style, and basic chromosome number x=8. Cyanixia was described as a new monotypic genus of Crocoideae
Crocoideae
Crocoideae is one of the major subfamilies in the Iridaceae family.It contains plants which are wildly distributed in the Old world, mainly in Africa, but there are species like some members of the genera Romulea and Gladiolus which are native to Europe and Asia...
, probably most closely allied to Savannosiphon
Savannosiphon
Savannosiphon is a genus of flowering plants in the family Iridaceae. The genus name, derived from the word savanna and the Greek word siphon alludes to its habitat and the structure of its perianth tube....
, also a genus with a single species.