In flowering plants, rosettes usually sit near the soil. Their structure is an example of a modified stem in which the internode gaps between the leaves do not expand, so that all the leaves remain clustered tightly together and at a similar height. Some insects induce the development of galls that are leafy rosettes.[1]
In bryophytes and algae, a rosette results from the repeated branching of the thallus as the plant grows, resulting in a circular outline.
Often, rosettes form in perennial plants whose upper foliage dies back with the remaining vegetation protecting the plant. Another form occurs when internodes along a stem are shortened, bringing the leaves closer together, as in lettuce, dandelion and some succulents.[2] (When plants such as lettuce grow too quickly, the stem lengthens instead, a condition known as bolting.) In yet other forms, the rosette persists at the base of the plant (such as the dandelion), and there is a taproot.
Part of the protective function of a rosette like the dandelion is that it is hard to pull from the ground; the leaves come away easily while the taproot is left intact.
Another kind of protection is provided by the caulescent rosette, which is part of the growth form of the giant genus Espeletia in South America, which has a well-developed stem above the ground.[3] In tropical alpine environments, a wide variety of plants in different plant families and different parts of the world have evolved this growth form characterized by evergreen rosettes growing above marcescent leaves. Examples where this arrangement has been confirmed to improve survival, help water balance, or protect the plant from cold injury are Espeletia schultzii and Espeletia timotensis, both from the Andes.[4][5]
Formedit
The rosette form is the structure, the relationship of the parts, and the variations within it, as shown in the following study from a herbarium:
Dryas octopetala (white dryas, Rosaceae) has a leaf rosette of leaf blades with a short petiole, slim, egg-shaped leaves with cordate bases with clearly and regularly toothed margins, and single flowers on usually long peduncles or stalks, two to four centimetres across. The flowers have seven to nine, often even more, white egg-shaped petals. The sepals are lanceolate.[6]
Silene nutans (Nottingham catchfly, Caryophyllaceae) shows ensiform-lanceolate leaves. The slightly rosette-like ground leaves are bigger and of different shape than the sparse, opposite leaves on the stem.[6] This is explained in that side shoots with greatly prolonged internodes may spring from rosettes. They have one or more flowers at their tip, like the primrose. Especially in biennial plants, the main shoot can grow with prolonged internodes and even branch. It is not unusual that the leaves of the rosette and those of the shoot differ in shape.[2]
As form, "rosette" is used to describe plants that perpetually grow as a rosette and the immature stage of plants such as some ferns.
^Netta Dorchin; Jeffrey B. Joy; Lukas K. Hilke; Michael J. Wise; Warren G. Abrahamson (14 May 2015). "Taxonomy and phylogeny of the Asphondylia species (Diptera: Cecidomyiidae) of North American goldenrods: challenging morphology, complex host associations, and cryptic speciation". Zoological Journal of the Linnean Society. 174 (2): 265–304. doi:10.1111/ZOJ.12234. ISSN 1096-3642. Wikidata Q99657406.
^ abBotany online: Features of Flowering Plants – Leaves
^Goldstein, G. and Meinzer, F.1983. Influence of insulating dead leaves and low temperatures on water balance in an Andean giant rosette plant. Plant, Cell & Environment 6: 649-656.
^Smith, Alan P.1979. Function of dead leaves in Espeletia schultzii (Compositae), and Andean caulescent rosette species. Biotropica 11: 43-47.
^ abBotany online: Features of flowering Plants – Rosettes – Whorls
December 15, 2023
rosette, botany, botany, rosette, circular, arrangement, leaves, structures, resembling, leaves, rosette, leaves, base, dandelionrosette, growth, form, liverwort, ricciocarpos, natans, flowering, plants, rosettes, usually, near, soil, their, structure, example. In botany a rosette is a circular arrangement of leaves or of structures resembling leaves A rosette of leaves at the base of a dandelionRosette growth form of the liverwort Ricciocarpos natans In flowering plants rosettes usually sit near the soil Their structure is an example of a modified stem in which the internode gaps between the leaves do not expand so that all the leaves remain clustered tightly together and at a similar height Some insects induce the development of galls that are leafy rosettes 1 In bryophytes and algae a rosette results from the repeated branching of the thallus as the plant grows resulting in a circular outline Contents 1 Taxonomies 2 Function in flowering plants 2 1 Protection 3 Form 4 See also 5 ReferencesTaxonomies editMany plant families have varieties with rosette morphology they are particularly common in Asteraceae such as dandelions Brassicaceae such as cabbage and Bromeliaceae The fern Blechnum fluviatile or New Zealand Water Fern kiwikiwi is a rosette plant Function in flowering plants editOften rosettes form in perennial plants whose upper foliage dies back with the remaining vegetation protecting the plant Another form occurs when internodes along a stem are shortened bringing the leaves closer together as in lettuce dandelion and some succulents 2 When plants such as lettuce grow too quickly the stem lengthens instead a condition known as bolting In yet other forms the rosette persists at the base of the plant such as the dandelion and there is a taproot Protection edit nbsp Rosette of leaves of Agave americanaPart of the protective function of a rosette like the dandelion is that it is hard to pull from the ground the leaves come away easily while the taproot is left intact Another kind of protection is provided by the caulescent rosette which is part of the growth form of the giant genus Espeletia in South America which has a well developed stem above the ground 3 In tropical alpine environments a wide variety of plants in different plant families and different parts of the world have evolved this growth form characterized by evergreen rosettes growing above marcescent leaves Examples where this arrangement has been confirmed to improve survival help water balance or protect the plant from cold injury are Espeletia schultzii and Espeletia timotensis both from the Andes 4 5 Form editThe rosette form is the structure the relationship of the parts and the variations within it as shown in the following study from a herbarium Dryas octopetala white dryas Rosaceae has a leaf rosette of leaf blades with a short petiole slim egg shaped leaves with cordate bases with clearly and regularly toothed margins and single flowers on usually long peduncles or stalks two to four centimetres across The flowers have seven to nine often even more white egg shaped petals The sepals are lanceolate 6 Silene nutans Nottingham catchfly Caryophyllaceae shows ensiform lanceolate leaves The slightly rosette like ground leaves are bigger and of different shape than the sparse opposite leaves on the stem 6 This is explained in that side shoots with greatly prolonged internodes may spring from rosettes They have one or more flowers at their tip like the primrose Especially in biennial plants the main shoot can grow with prolonged internodes and even branch It is not unusual that the leaves of the rosette and those of the shoot differ in shape 2 As form rosette is used to describe plants that perpetually grow as a rosette and the immature stage of plants such as some ferns See also editAsteraceae Bromeliad Billbergia Fern Bird s nest fern Ostrich fern Wild bird s nest fernReferences edit Netta Dorchin Jeffrey B Joy Lukas K Hilke Michael J Wise Warren G Abrahamson 14 May 2015 Taxonomy and phylogeny of the Asphondylia species Diptera Cecidomyiidae of North American goldenrods challenging morphology complex host associations and cryptic speciation Zoological Journal of the Linnean Society 174 2 265 304 doi 10 1111 ZOJ 12234 ISSN 1096 3642 Wikidata Q99657406 a b Botany online Features of Flowering Plants Leaves shows many images Archived 2008 07 05 at the Wayback Machine Goldstein G and Meinzer F 1983 Influence of insulating dead leaves and low temperatures on water balance in an Andean giant rosette plant Plant Cell amp Environment 6 649 656 Smith Alan P 1979 Function of dead leaves in Espeletia schultzii Compositae and Andean caulescent rosette species Biotropica 11 43 47 a b Botany online Features of flowering Plants Rosettes Whorls Retrieved from https en wikipedia org w index php title Rosette botany amp oldid 1177038663, wikipedia, wiki, book, books, library,
