Degeneria

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Degeneria
Degeneria vitiensis.png
Degeneria vitiensis
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Magnoliids
Order: Magnoliales
Family: Degeneriaceae
I.W.Bailey & A.C.Sm. [1]
Genus: Degeneria
I.W. Bailey & A.C.Sm.
Species

Degeneria is a genus of flowering plants endemic to Fiji. It is the only genus in the family Degeneriaceae. The APG IV system of 2016 (unchanged from the APG system of 1998, the APG II system of 2003 and the APG III system of 2009), recognizes this family, and assigns it to the order Magnoliales in the clade magnoliids. [1] [2]

Contents

Degeneria was named after Otto Degener, who first found D. vitiensis in 1942. Classical studies of native stands of Degeneria from Vanua Levu and Viti Levu islands were conducted more than 30 years ago. [3] [4] [5]

A 45-cent stamp issued in 1988 depicted a flowering branch of Degeneria vitiensis. This species appears on Fiji's five-dollar bill. A one-dollar 1988 philatelic commemorated the discovery of Degeneria roseiflora earlier in that same year.

The genus contains two species of trees, both native to Fiji: [6] [7]

Floral structure

The stage-specific movements of floral organs, including scent emissions of degenerias studied by Miller in 1989, are remarkably similar to those observed in other Magnoliales. [8] [9] [10] Further, the floral structure of Degeneria is unusual, considered to be primitive among the flowering plants. [11] The stamens are similar to those in Austrobaileya , Galbulimima , and some Magnoliaceae; they do not have distinguishable anther, filament, and connective, but instead are leaf-like, with two pairs of microsporangia embedded in the surface. There are three veins, rather than the single vein in the stamen of most flowering plants. [11] The gynoecium develops in an unusual way, similar to Winteraceae, with laminal placentation, i.e., the young carpel is cup-shaped, and the ovules develop on its upper surface. The margins of the carpel never fully fuse. A cleft remains filled with hairs, through which the pollen tubes grow towards the ovules. [11]

Related Research Articles

<span class="mw-page-title-main">Apiales</span> Order of eudicot flowering plants in the asterid group

The Apiales are an order of flowering plants. The families are those recognized in the APG III system. This is typical of the newer classifications, though there is some slight variation and in particular, the Torriceliaceae may also be divided.

<span class="mw-page-title-main">Flowering plant</span> Clade of seed plants that produce flowers

Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae, commonly called angiosperms. They include all forbs, grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs and vines, and most aquatic plants. The term "angiosperm" is derived from the Greek words ἀγγεῖον / angeion and σπέρμα / sperma ('seed'), meaning that the seeds are enclosed within a fruit. They are by far the most diverse group of land plants with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species. Angiosperms were formerly called Magnoliophyta.

<span class="mw-page-title-main">Magnoliales</span> Basal order of flowering plants

The Magnoliales are an order of flowering plants.

<span class="mw-page-title-main">Crossosomatales</span> Order of flowering plants

The Crossosomatales are an order, first recognized as such by APG II. They are flowering plants included within the Rosid eudicots.

<i>Amborella</i> Species of shrub

Amborella is a monotypic genus of understory shrubs or small trees endemic to the main island, Grande Terre, of New Caledonia in the southwest Pacific Ocean. The genus is the only member of the family Amborellaceae and the order Amborellales and contains a single species, Amborella trichopoda. Amborella is of great interest to plant systematists because molecular phylogenetic analyses consistently place it as the sister group to all other flowering plants, meaning it was the earliest group to evolve separately from all other flowering plants.

<span class="mw-page-title-main">Canellaceae</span> Family of flowering plants

The Canellaceae are a family of flowering plants in the order Canellales. The order includes only one other family, the Winteraceae. Canellaceae is native to the Afrotropical and Neotropical realms. They are small to medium trees, rarely shrubs, evergreen and aromatic. The flowers and fruit are often red.

<span class="mw-page-title-main">Gynoecium</span> Female organs of a flower

Gynoecium is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of pistils and is typically surrounded by the pollen-producing reproductive organs, the stamens, collectively called the androecium. The gynoecium is often referred to as the "female" portion of the flower, although rather than directly producing female gametes, the gynoecium produces megaspores, each of which develops into a female gametophyte which then produces egg cells.

<span class="mw-page-title-main">Schisandraceae</span> Family of flowering plants

Schisandraceae is a family of flowering plants with 3 known genera and a total of 92 known species. Such a family has been recognized by most taxonomists, at least for the past several decades. Before that, the plants concerned were assigned to family Magnoliaceae and Illiciaceae.

<span class="mw-page-title-main">Sabiaceae</span> Family of flowering plants

Sabiaceae is a family of flowering plants that were placed in the order Proteales according to the APG IV system. It comprises three genera, Meliosma, Ophiocaryon and Sabia, with 66 known species, native to tropical to warm temperate regions of southern Asia and the Americas. The family has also been called Meliosmaceae Endl., 1841, nom. rej.

<span class="mw-page-title-main">Trochodendraceae</span> Family of flowering plants

Trochodendraceae is the only family of flowering plants in the order Trochodendrales. It comprises two extant genera, each with a single species along with up to five additional extinct genera and a number of extinct species. The living species are native to south east Asia. The two living species both have secondary xylem without vessel elements, which is quite rare in angiosperms. As the vessel-free wood suggests primitiveness, these two species have attracted much taxonomic attention.

<span class="mw-page-title-main">Peridiscaceae</span> Family of flowering plants in the order Saxifragales

Peridiscaceae is a family of flowering plants in the order Saxifragales. Four genera comprise this family: Medusandra, Soyauxia, Peridiscus, and Whittonia., with a total of 12 known species. It has a disjunct distribution, with Peridiscus occurring in Venezuela and northern Brazil, Whittonia in Guyana, Medusandra in Cameroon, and Soyauxia in tropical West Africa. Whittonia is possibly extinct, being known from only one specimen collected below Kaieteur Falls in Guyana. In 2006, archeologists attempted to rediscover it, however, it proved unsuccessful.

<span class="mw-page-title-main">Trimeniaceae</span> Family of flowering plants

Trimeniaceae is a family of flowering plants recognized by most taxonomists, at least for the past several decades. It is a small family of one genus, Trimenia, with eight known species of woody plants, bearing essential oils. The family is subtropical to tropical and found in Southeast Asia, eastern Australia and on several Pacific Islands.

<i>Eupomatia</i> Genus of flowering plants

Eupomatia is a genus of three species of plants in the ancient family Eupomatiaceae, and is the sole genus in the family. Eupomatiaceae is recognised by most taxonomists and classified in the plant order Magnoliales. The three described species are shrubs or small trees, native to the rainforests and humid eucalypt forests of eastern Australia and New Guinea. The type species Eupomatia laurina was described in 1814 by Robert Brown.

<span class="mw-page-title-main">Himantandraceae</span> Family of plants

Himantandraceae is a family of flowering plants recognized by the APG II system of 2003, assigned to the order Magnoliales in the clade magnoliids. The family consists of only one genus, Galbulimima, of probably two species, trees and shrubs, found in tropical areas in Southeast Asia and Australia.

<i>Didymeles</i> Genus of trees

Didymeles is a genus of flowering plants. It is variously treated as the only genus of the family Didymelaceae — or in the family Buxaceae, as in the APG IV system.

<span class="mw-page-title-main">Huerteales</span> Order of flowering plants

Huerteales is the botanical name for an order of flowering plants. It is one of the 17 orders that make up the large eudicot group known as the rosids in the APG III system of plant classification. Within the rosids, it is one of the orders in Malvidae, a group formerly known as eurosids II and now known informally as the malvids. This is true whether Malvidae is circumscribed broadly to include eight orders as in APG III, or more narrowly to include only four orders. Huerteales consists of four small families, Petenaeaceae, Gerrardinaceae, Tapisciaceae, and Dipentodontaceae.

<span class="mw-page-title-main">Loasaceae</span> Family of flowering plants

Loasaceae is a family of 15–20 genera and about 200–260 species of flowering plants in the order Cornales, native to the Americas and Africa. Members of the family include annual, biennial and perennial herbaceous plants, and a few shrubs and small trees. Members of the subfamily Loasoideae are known to exhibit rapid thigmonastic stamen movement when pollinators are present.

<span class="mw-page-title-main">Basal angiosperms</span> Descendants of most extant flowering plants

The basal angiosperms are the flowering plants which diverged from the lineage leading to most flowering plants. In particular, the most basal angiosperms were called the ANITA grade, which is made up of Amborella, Nymphaeales and Austrobaileyales.

<span class="mw-page-title-main">Fiji tropical moist forests</span>

The Fiji tropical moist forests is a tropical moist forest ecoregion in Fiji and Wallis and Futuna. It covers the windward sides of Viti Levu and Vanua Levu, Fiji's largest islands, as well as the smaller Fijian islands and the three islands that make up Wallis and Futuna, an overseas territory of France. The drier leeward sides of Viti Levu and Vanua Levu are home to the distinct Fiji tropical dry forests ecoregion.

<i>Degeneria vitiensis</i> Species of tree

Degeneria vitiensis is a flowering tree found on Viti Levu in Fiji. It is known as masiratu and vāvāloa in Fijian, although the latter is also used for Litsea magnifolia. It is a relatively common plant and is used as timber. It has been found in upland forests on steep slopes.

References

  1. 1 2 Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III". Botanical Journal of the Linnean Society. 161 (2): 105–121. doi: 10.1111/j.1095-8339.2009.00996.x . hdl: 10654/18083 .
  2. "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV". Botanical Journal of the Linnean Society. 181 (1): 1–20. 2016. doi: 10.1111/boj.12385 . ISSN   0024-4074.
  3. Miller, J. M. 1988. A new species of Degeneria (Degeneriaceae) from Fiji Archipelago. Journal of the Arnold Arboretum 69: 275–280
  4. Miller, J. M. 1988. Puzzling new floral variation in a possible Mesozoic relict flowering plant, Fiji Islands. P. 4, In: H. J. de Blij (ed.), Letters, National Geographic Research Volume 4. Washington, D. C.: National Geographic Society, 144 pp.
  5. Miller, J. M. 1989. The archaic flowering plant family Degeneriaceae: its bearing on an old enigma. National Geographic Research 5(2): 218–231
  6. "Degeneria I.W.Bailey & A.C.Sm". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-12-27.
  7. Smith, A. C. 1991. Degeneriaceae Pp. 587-588 In: A. C. Smith, Flora Vitiensis Nova, Volume 5. Lawai: National Tropical Botanical Garden, 626 pp.
  8. Bernhardt, P. and L. B. Thien. 1987. Self-isolation and insect pollination in the primitive angiosperms: new evaluations of older hypotheses. Plant Systematics and Evolution 156(3–4): 159–176
  9. Pang, C.-C. and R. M. K. Saunders. 2014. The evolution of alternative mechanisms that promote outcrossing in Annonaceae: a self-compatible family of early divergent angiosperms. Botanical Journal of the Linnean Society 174: 93–109
  10. Pang, C.-C. and R. M. K. Saunders. 2015. Floral biology and pollination ecology of Desmos chinensis (Annonaceae): Assessing the efficacy of floral synchrony for promoting xenogamy. International Journal of Plant Sciences 176(4): 333–345
  11. 1 2 3 Gifford, E.M.; Foster, A.S. (1989). Morphology and evolution of vascular plants. New York: W. H. Freeman and Company.