| Isoetes stellenbossiensis | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Lycophytes |
| Class: | Lycopodiopsida |
| Order: | Isoetales |
| Family: | Isoetaceae |
| Genus: | Isoetes |
| Species: | I. stellenbossiensis |
| Binomial name | |
| Isoetes stellenbossiensis | |
Isoetes stellenbossiensis, the Stellenbosch quillwort or Cape Flats quillwort, is a species of plant from South Africa.
This tufted geophyte has three-pointed scales. There are between five and thirty three spore bearing leaves, each of which grows up to 12 cm (4.7 in) long. [1] This is the smallest Isoetes species in the region. [2] The leaves have three well-developed groups of supporting tissue inside, giving them a firm texture. The air canals are poorly developed, with the adaxial canal ending 2 cm (0.79 in) before the end of the leaf. [3] Each leaf has a small and delicate elongated appendage at its base. It starts off triangular, but often decays somewhat over time. [3]
The sporangia vary in size and do not have a membranous covering. [1] [3] They are usually bordered by a narrow rim, with some of the cells being noticeably thicker and a yellowish-brown in colour. The older megasporangia are usually circular while the younger megasporangia are more elongated. The microsporangia have conspicuous gaps. The innermost micropsorangia are often angled due to pressure that has been exerted on them. [3]
While the species in this genus typically have white spores, those of Isoetes stellenbossiensis have a distinctive greenish tinge and become darker when exposed to water. [3] The megaspores are spherical and have a diameter of 0.45–0.59 mm (0.018–0.023 in). The microspores are more brownish than the megaspores and have a length of 0.032–0.036 mm (0.0013–0.0014 in) of and breadth of 0.016–0.024 mm (0.00063–0.00094 in). [3]
A three-lobed corm remains during the dry season. [2] [3] It has a diameter of about 1.5 cm (0.59 in) and have a harsh texture. [3] They are protected by black bud scales with three horny, prong-like teeth. [2] [3] They tend to be buried at a uite deeply, up to a depth of at least 6 cm (2.4 in). [3] The corm is covered in caps of old cortex, each of which will remain for several years. They are difficult to remove, even if the corm has been soaked. [3]
This quillwort is found growing in the Western Cape of South Africa - between Tulbagh, the Cape Flats and Stellenbosch - at an altitude of up to 300 m (980 ft). [4] It is sometimes also found in the parts of the Northern Cape that border the Western Cape, although it has also been suggested that this might be a new species. [2] [5] It grows on waterlogged soils and seeps on granite outcrops. [4]
The species is named after the Stellenbosch flats where it was first discovered. [2]
This quillwort can form large colonies of thousands of individuals when conditions are suitable. [2] [5] In fact, in some places they may grow so densely that they may be mistaken for a fine-lefed grass. [3] It can still, however, still be difficult to find these plants as they are small and often associate with other species. [2] These species include the shrub Psoralea pinnata as well as multiple species of grasses, sedges and geophytes.
This is a seasonal species. Plants die off as its habitat dries, leaving behind a corm. This species, dpes however, have the highest tolerance to a low moisture environment out of the South African Isoetes species, and is able to be fully terrestrial during the rainy season. [3] It may even be found growing with highly drought tolerent species such as Crassula dejecta , Aristea africana , and Oedera fruticosa . [3]
In an assessment conducted in 2006, the IUCN classified this species as near threatened. [6] It is, however, probably the most common Isoetes species in South Africa. [2] An assessment conducted by the South African National Biodiversity Institute in 2020 classified this species as least concern as, while this species was still declining, the assessors believed that the population was still common enough with large enough subpopulations to not be at immediate risk of extinction. [5]
Isoetes, commonly known as the quillworts, is a genus of lycopod. It is the only living genus in the family Isoetaceae and order Isoetales. There are currently 192 recognized species, with a cosmopolitan distribution mostly in aquatic habitats but with the individual species often scarce to rare. Some botanists split the genus, separating two South American species into the genus Stylites, although molecular data place these species among other species of Isoetes, so that Stylites does not warrant taxonomic recognition. Species virtually identical to modern quillworts have existed since the Jurassic epoch, though the timing of the origin of modern Isoetes is subject to considerable uncertainty.
Isoetes lacustris, the lake quillwort or Merlin's grass, is a boreal quillwort native on both sides of the northern Atlantic Ocean. Synonyms include Isoetes hieroglyphica.
Isoetes eludens is an aquatic plant in the genus commonly known as quillwort that is native to the Kamiesberg Mountains in Namaqualand, South Africa. So far it is known to grow only in a single !gau (gnamma), a small temporary pool formed in a hollowed out area of granite rock. It has likely been growing in that region for millions of years, but was only discovered in 2007 and described in 2009. The specific epithet eludens refers to the fact that it eluded discovery, in spite of several searches in recent years in the area for new quillwort species.
Moraea aristata is a species of flowering plant in the family Iridaceae. It is referred to by the common names blue-eyed uintjie or Blouooguintjie in Afrikaans.It is endemic to the city of Cape Town and is considered to be critically endangered.
Baeometra is a genus in the family Colchicaceae containing a single species, Baeometra uniflora. It is native to South Africa, where it is commonly called beetle lily due to the dark markings on the tepals.
Gladiolus alatus is a species of geophyte from South Africa. Common names include painted ladies, king kalkoentjie and kipkippie. Kalkoentjie means "little turkey" in Afrikaans and refers to the shape of the flower, which resembles a turkey's wattle. It is popular as a garden plant and an important part of the cut flower industry in parts of the world on account of its large and showy orange flowers.
Ixia monadelpha, also known as the pied kalossie or bontkalossie, is an endangered species of geophyte found in wet sandy flats in the southwestern Cape of South Africa.
Isoetes toximontana, the Gifberg quillwort, is a plant species native to the Northern Cape and Western Cape regions of South Africa. It is known from only 3 sites. The type locality is on the slopes of Gifberg, a mountain forming part of the eastern boundary of the Olifants River Valley. The name "Gifberg" means "poison mountain"; this is in reference to a poisonous tree called "gifboom", Euphorbia virosa, that is endemic to the area. The specific epithet "toximontana" is a Latin translation of the Afrikaans name of the mountain.
Geissorhiza aspera, also known as the blue satin flower or blou sysie, is a geophyte from South Africa.
Isoetes echinospora, also known as spiny quillwort, spiny-spored quillwort or spring quillwort is a species of quillwort in the Isoetaceae family, and is the most abundant species in Canada. It can be found in shallow aquatic environments from Labrador and Newfoundland to Alaska, and south to Pennsylvania, Wisconsin, Michigan, Colorado, and California. In Germany it is found in only two locations: the Feldsee and Lake Titisee, both in the High Black Forest.
Lobostemon collinus, the pyjamabush or iron healthbush, is a species belonging to the forget me not family. It is known only from the fynbos biome of the Western Cape of South Africa.
Isoetes capensis, the cape quillwort, is a species of quillwort from South Africa.
Cheiridopsis schlechteri is a species of plant from South Africa. It is a succulent plant that grows in dry habitats.
Osmitopsis parvifolia is a species of plant from South Africa.
Hebenstretia lanceolata is a species of plant from South Africa. It belongs to the figwort family.
Romulea hirsuta is a geophyte from South Africa. It has pink flowers with dark marks at the edges of the yellow center.
Isoetes stephanseniae, the granite quillwort, is a species of quillwort from South Africa, named for A. J. Stephansen, who discovered it in 1927. Of very limited distribution, it is known to survive only as one population in seasonal pools over granite near Stellenbosch, where it is threatened by the encroachment of alien species and eutrophication from the sewage works on whose grounds it grows. Like other quillworts, it bears a tuft of leaves with distinctively sculpted megaspores. It is most similar to Isoetes capensis, the cape quillwort, which occurs in the same province; both hold their leaves at a 45-degree angle, unlike most South African quillworts which have leaves stiffly erect.
Lachenalia unifolia, the banded viooltjie, is the most common Lachenalia species in the Cape Floristic Region of South Africa.
Lachenalia variegata, also known as the spotty viooltjie, is a species of plant from the Western Cape of South Africa.