| Brachyscome dichromosomatica | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Brachyscome |
| Species: | B. dichromosomatica |
| Binomial name | |
| Brachyscome dichromosomatica C.R.Carter | |
Brachyscome dichromosomatica is a small flowering plant that is found in parts of Australia. It is notable for its exceptionally low chromosome number of 2n=4, the smallest known among land plants.
Brachyscome dichromosomatica is an ephemeral plant that grows upright up to 25 centimeters tall. The leaves either grow from the base of the plant or from the lower part of its scape (stem). The leaf blades are up to 8 cm long with 5–9 distinct segments. The scape lacks hairs and grows straight upright with a length of 3–25 cm. The flower head grows up to 1.3 cm wide. It contains 8–13 involucral bracts that are 0.15–0.4 cm broad and are sometimes a reddish-purple color. There are 8–16 florets on ligules that are 0.5–1.2 cm long and range in color from white to blue. The pollen receptacle is 0.2–0.3 cm wide and is hemispherical with deep pits. The fruit is a wide, roughly triangular shape in profile, with a tapering cylindrical body. It is covered in silky hairs on its edges. Surrounding the fruit is a visible pappus with bristles of varying lengths. [1]
Brachyscome dichromosomatica was described by Charles Carter in 1978. The species was divided from Brachyscome lineariloba because of the wide variation in appearance of B. lineariloba. Together with Brachyscome breviscapis , these new species made up the "Brachyscome lineariloba species complex" of closely related taxa. [2] Within this complex is Brachyscome eriogona, another particularly similar species. B. dichromosomatica differs from B. eriogona by the shape of its achenes and its larger size. [3]
Carter also established two varieties of B. dischromosomatica based on the color of the plant's ligules: those of var. alba are white while those of var. dichromosomatica are light blue. [2]
Brachyscome dichromosomatica has a chromosome number of 2n=4. It is one of only six angiosperms and two dicotyledons with this low number, the other dicotyledon being Rhynchospora tenuis . [4]
In addition to its two pairs of standard chromosomes, the species also can contain up to three accessory chromosomes, or "B chromosomes". [5] It is the only plant with a chromosome number of 2n=4 and additional B chromosomes. [6] There are two types of B chromosomes: large, which are stable, and micro, which are not. A Brachyscome dichromosomatica plant has one of four different suites of accessory chromosomes in arrangements called cytodemes (A1, A2, A3, A4). When the four cytodemes arose is unknown, but A4 is believed to be the oldest and A3 the most isolated. All of the B chromosomes contain inert ribosomal DNA that is not transcribed. [7]
The species is native to the provinces of South Australia and New South Wales in Australia. [3] The alba variety is only found in New South Wales. [8] The plants have a habitat of dried riverbeds and claypans. [3]
Gundelia or tumble thistle is a low to high (20–100 cm) thistle-like perennial herbaceous plant with latex, spiny compound inflorescences, reminiscent of teasles and eryngos, that contain cream, yellow, greenish, pink, purple or redish-purple disk florets. It is assigned to the family Asteraceae. Flowers can be found from February to May. The stems of this plant dry-out when the seeds are ripe and break free from the underground root, and are then blown away like a tumbleweed, thus spreading the seeds effectively over large areas with little standing vegetation. This plant is native to the eastern Mediterranean and the Middle-East. Opinions differ about the number of species in Gundelia. Sometimes the genus is regarded monotypic, Gundelia tournefortii being a species with a large variability, but other authors distinguish up to nine species, differing in floret color and pubescence. Young stems are cooked and eaten in the Middle-East and are said to taste like a combination of artichoke and asparagus.
Byblis is a small genus of carnivorous plants, sometimes termed the rainbow plants for the attractive appearance of their mucilage-covered leaves in bright sunshine. Native to Australia and New Guinea, it is the only genus in the family Byblidaceae. The first species in the genus was described by the English botanist Richard Anthony Salisbury in 1808. Eight species are now recognised.
Drosera regia, commonly known as the king sundew, is a carnivorous plant in the sundew genus Drosera that is endemic to a single valley in South Africa. The genus name Drosera comes from the Greek word droseros, meaning "dew-covered". The specific epithet regia is derived from the Latin for "royal", a reference to the "striking appearance" of the species. Individual leaves can reach 70 cm (28 in) in length. It has many unusual relict characteristics not found in most other Drosera species, including woody rhizomes, operculate pollen, and the lack of circinate vernation in scape growth. All of these factors, combined with molecular data from phylogenetic analysis, contribute to the evidence that D. regia possesses some of the most ancient characteristics within the genus. Some of these are shared with the related Venus flytrap (Dionaea muscipula), which suggests a close evolutionary relationship.
Genlisea aurea is one of the largest carnivorous species in the genus Genlisea. It has pale bundles of root-like organs up to about 15 cm long under ground that attract, trap, and digest protozoans. These organs are subterranean leaves, which lack chlorophyll. G. aurea is endemic to Brazil, where it grows with several other species of Genlisea. It possesses an exceptionally small genome for a flowering plant.
Takakia is a genus of two species of mosses known from western North America and central and eastern Asia. The genus is placed as a separate family, order and class among the mosses. It has had a history of uncertain placement, but the discovery of sporophytes clearly of the moss-type firmly supports placement with the mosses.
Brachyscome is a genus of flowering plants in the family Asteraceae. Most are endemic to Australia, and a few occur in New Zealand and New Guinea.
Drosera indica is an insectivorous plant, a sundew native to tropical countries throughout the world, from Asia to Africa, but absent from the neotropics. Together with Australian endemic species D. aquatica, D. aurantiaca, D. barrettorum, D. cucullata, D. finlaysoniana, D. fragrans, D. glabriscapa, D. hartmeyerorum, D. nana, D. serpens it makes up the section Arachnopus.
Drosera linearis, commonly called the slenderleaf sundew, is a sundew found in the Great Lakes region of North America, in Canada and the United States, such as Michigan, and in Montana. It is usually no more than four inches tall.
Brachyscome multifida is a perennial herb in the family Asteraceae. Common names include cut-leaved daisy, rocky daisy, and Hawkesbury daisy. The species is endemic to Australia.
Brachyscome segmentosa, commonly known as the Lord Howe Island daisy or mountain daisy, is a herb in the family Asteraceae. The specific epithet comes from the Latin segmentum ("segment") with the suffix -osa, alluding to the many deep divisions of the leaf.
Catananche lutea, is a woolly annual plant, in the family Asteraceae, with most leaves in a basal rosette, and some smaller leaves on the stems at the base of the branches. Seated horizontal flowerheads develop early on under the rosette leaves. Later, not or sparingly branching erect stems grow to 8–40 cm high, carrying solitary flowerheads at their tips with a papery involucre whitish to beige, reaching beyond the yellow ligulate florets. Flowers are present between April and June. This plant is unique for the five different types of seed it develops, few larger seeds from the basal flowerheads, which remain in the soil, and smaller seeds from the flowerheads above ground that may be spread by the wind or remain in the flowerhead when it breaks from the dead plant. This phenomenon is known as amphicarpy. The seeds germinate immediately, but in one type, germination is postponed. It naturally occurs around the Mediterranean. Sources in English sometimes refer to this species as yellow succory.
Brachyscome aculeata, commonly known as hill daisy, is a tufted perennial herb in the family Asteraceae and is endemic to Australia. It has mostly white daisy-like flowers, a yellow centre, variable shaped leaves and flowers in spring to autumn.
Brachyscome ascendens, the border ranges daisy, is a species of flowering plant in the family Asteraceae and is endemic to Australia. It has mostly mauve daisy-like flowers and a yellow centre.
Brachyscome graminea, commonly known as grass daisy, is a perennial herb in the family Asteraceae and is endemic to Australia. It has mostly mauve-pink or purple daisy-like flowers and a yellow centre.
Brachyscome decipiens, commonly known as field daisy, is a perennial herb in the family Asteraceae and is endemic to Australia. It is a small herb with white or pale blue flowers.
Brachyscome dentata, commonly known as lobe-seed daisy, is a tufted perennial herb in the family Asteraceae and is endemic to Australia. It has mostly white or mauve daisy-like flowers, a yellow centre and pale green leaves. It is endemic to Australia.
Tragus racemosus, commonly referred to as stalked bur grass, European bur grass, or large carrot seed grass, is a species of grass native to Europe. It is often confused with a similar plant of the same genus, Tragus berteronianus. It is a monocot and is considered a weed in many countries and is a relatively uncommon seed contaminant.
Carex elongata, the elongated sedge, is a species of flowering plant in the family Cyperaceae, native to Europe, the Caucasus, western Siberia, Kazakhstan, and the Altai. It occurs in boggy woodland and wet meadows, where it forms dense tussocks up to about 1 m tall.
Brachyscome bellidioides is a species of flowering plant in the family Asteraceae and is endemic to the southwest of Western Australia. It is an annual herb with linear leaves and yellow and white daisy-like flowers.
Brachyscome spathulata, commonly known as spoon-leaved daisy, is a flowering plant in the family Asteraceae. It has dark green leaves, mauve daisy-like flowers and grows in New South Wales, Tasmania, Victoria and the Australian Capital Territory.