Flowering plant explained

Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae,[1] [2] commonly called angiosperms. They include all forbs (flowering plants without a woody stem), 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 / Greek, Ancient (to 1453);: angeion ('container, vessel') and σπέρμα / Greek, Ancient (to 1453);: 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.[3] Angiosperms were formerly called Magnoliophyta .

Angiosperms are distinguished from the other seed-producing plants, the gymnosperms, by having flowers, xylem consisting of vessel elements instead of tracheids, endosperm within their seeds, and fruits that completely envelop the seeds.The ancestors of flowering plants diverged from the common ancestor of all living gymnosperms before the end of the Carboniferous, over 300 million years ago. In the Cretaceous, angiosperms diversified explosively, becoming the dominant group of plants across the planet.

Agriculture is almost entirely dependent on angiosperms, and a small number of flowering plant families supply nearly all plant-based food and livestock feed. Rice, maize, and wheat provide half of the world's calorie intake, and all three plants are cereals from the Poaceae family (colloquially known as grasses). Other families provide materials such as wood, paper and cotton, and supply numerous ingredients for traditional and modern medicines. Flowering plants are also commonly grown for decorative purposes, with certain flowers playing a significant role in many cultures.

Out of the "Big Five" extinction events in Earth's history, only the Cretaceous–Paleogene extinction event had occurred while angiosperms dominated plant life on the planet. Today, the Holocene extinction affects all kingdoms of complex life on Earth, and conservation measures are necessary to protect plants in their habitats in the wild (in situ), or failing that, ex situ in seed banks or artificial habitats like botanic gardens. Otherwise, around 40% of plant species may become extinct due to human actions such as habitat destruction, introduction of invasive species, unsustainable logging and collection of medicinal or ornamental plants. Further, climate change is starting to impact plants and is likely to cause many species to become extinct by 2100.

Distinguishing features

Angiosperms are terrestrial vascular plants; like the gymnosperms, they have roots, stems, leaves, and seeds. They differ from other seed plants in several ways.

Feature Description Image
Flowers The reproductive organs of flowering plants, not found in any other seed plants.[4]
Reduced gametophytes, three cells in male, seven cells with eight nuclei in female (except for basal angiosperms)[5] The gametophytes are smaller than those of gymnosperms.[6] The smaller size of the pollen reduces the time between pollination and fertilization, which in gymnosperms is up to a year.[7]
Endosperm forms after fertilization but before the zygote divides. It provides food for the developing embryo, the cotyledons, and sometimes the seedling.[8]
Closed carpel enclosing the ovules. Once the ovules are fertilised, the carpels, often with surrounding tissues, develop into fruits. Gymnosperms have unenclosed seeds.[9]
Xylem made of vessel elements Open vessel elements are stacked end to end to form continuous tubes, whereas gymnosperm xylem is made of tapered tracheids connected by small pits.[10]

Diversity

Ecological diversity

The largest angiosperms are Eucalyptus gum trees of Australia, and Shorea faguetiana, dipterocarp rainforest trees of Southeast Asia, both of which can reach almost 100m (300feet) in height.[11] The smallest are Wolffia duckweeds which float on freshwater, each plant less than 2mm across.[12]

Considering their method of obtaining energy, some 99% of flowering plants are photosynthetic autotrophs, deriving their energy from sunlight and using it to create molecules such as sugars. The remainder are parasitic, whether on fungi like the orchids for part or all of their life-cycle,[13] or on other plants, either wholly like the broomrapes, Orobanche, or partially like the witchweeds, Striga.[14]

In terms of their environment, flowering plants are cosmopolitan, occupying a wide range of habitats on land, in fresh water and in the sea. On land, they are the dominant plant group in every habitat except for frigid moss-lichen tundra and coniferous forest.[15] The seagrasses in the Alismatales grow in marine environments, spreading with rhizomes that grow through the mud in sheltered coastal waters.[16]

Some specialised angiosperms are able to flourish in extremely acid or alkaline habitats. The sundews, many of which live in nutrient-poor acid bogs, are carnivorous plants, able to derive nutrients such as nitrate from the bodies of trapped insects.[17] Other flowers such as Gentiana verna, the spring gentian, are adapted to the alkaline conditions found on calcium-rich chalk and limestone, which give rise to often dry topographies such as limestone pavement.[18]

As for their growth habit, the flowering plants range from small, soft herbaceous plants, often living as annuals or biennials that set seed and die after one growing season,[19] to large perennial woody trees that may live for many centuries and grow to many metres in height. Some species grow tall without being self-supporting like trees by climbing on other plants in the manner of vines or lianas.[20]

Taxonomic diversity

The number of species of flowering plants is estimated to be in the range of 250,000 to 400,000.[21] [22] [23] This compares to around 12,000 species of moss[24] and 11,000 species of pteridophytes.[25] The APG system seeks to determine the number of families, mostly by molecular phylogenetics. In the 2009 APG III there were 415 families. The 2016 APG IV added five new orders (Boraginales, Dilleniales, Icacinales, Metteniusales and Vahliales), along with some new families, for a total of 64 angiosperm orders and 416 families.

The diversity of flowering plants is not evenly distributed. Nearly all species belong to the eudicot (75%), monocot (23%), and magnoliid (2%) clades. The remaining five clades contain a little over 250 species in total; i.e. less than 0.1% of flowering plant diversity, divided among nine families. The 25 most species-rich of 443 families,[26] containing over 166,000 species between them in their APG circumscriptions, are:

The 25 largest angiosperm families
Group English name
Eudicot Asteraceae or Compositae 22,750
Monocot 21,950
Eudicot Fabaceae or Leguminosae 19,400
Eudicot 13,150 [27]
Monocot Poaceae or Gramineae 10,035
Eudicot Lamiaceae or Labiatae 7,175
Eudicot 5,735
Eudicot 5,005
Eudicot 4,625
Eudicot 4,555
Monocot 4,350
Eudicot 4,225
Monocot 4,025
Eudicot 3,995
Eudicot gesneriad 3,870
Eudicot Apiaceae or Umbelliferae 3,780
Eudicot Brassicaceae or Cruciferae 3,710
Magnoliid dicot 3,600
Monocot bromeliad 3,540
Eudicot 3,500
Eudicot 2,830
Eudicot 2,740
Eudicot 2,625
Eudicot 2,525
Magnoliid dicot 2,500

Evolution

History of classification

See main article: Plant taxonomy.

The botanical term "angiosperm", from Greek words Greek, Ancient (to 1453);: angeíon ('bottle, vessel') and Greek, Ancient (to 1453);: spérma ('seed'), was coined in the form "Angiospermae" by Paul Hermann in 1690, including only flowering plants whose seeds were enclosed in capsules. The term angiosperm fundamentally changed in meaning in 1827 with Robert Brown, when angiosperm came to mean a seed plant with enclosed ovules.[28] [29] In 1851, with Wilhelm Hofmeister's work on embryo-sacs, Angiosperm came to have its modern meaning of all the flowering plants including Dicotyledons and Monocotyledons.[29] The APG system treats the flowering plants as an unranked clade without a formal Latin name (angiosperms). A formal classification was published alongside the 2009 revision in which the flowering plants rank as the subclass Magnoliidae. From 1998, the Angiosperm Phylogeny Group (APG) has reclassified the angiosperms, with updates in the APG II system in 2003, the APG III system in 2009,[30] and the APG IV system in 2016.

Phylogeny

External

In 2019, a molecular phylogeny of plants placed the flowering plants in their evolutionary context:[31]

Internal

The main groups of living angiosperms are:[32]

In 2024, Alexandre R. Zuntini and colleagues constructed a tree of some 6,000 flowering plant genera, representing some 60% of the existing genera, on the basis of analysis of 353 nuclear genes in each specimen. Much of the existing phylogeny is confirmed; the rosid phylogeny is revised.[33]

Fossil history

Fossilised spores suggest that land plants (embryophytes) have existed for at least 475 million years.[34] However, angiosperms appear suddenly and in great diversity in the fossil record in the Early Cretaceous (~130 mya).[35] [36] Claimed records of flowering plants prior to this are not widely accepted.[37] Molecular evidence suggests that the ancestors of angiosperms diverged from the gymnosperms during the late Devonian, about 365 million years ago.[38] The origin time of the crown group of flowering plants remains contentious.[39] By the Late Cretaceous, angiosperms appear to have dominated environments formerly occupied by ferns and gymnosperms. Large canopy-forming trees replaced conifers as the dominant trees close to the end of the Cretaceous, 66 million years ago.[40] The radiation of herbaceous angiosperms occurred much later.[41]

Reproduction

Flowers

See main article: Flower and Plant reproductive morphology.

The characteristic feature of angiosperms is the flower. Its function is to ensure fertilization of the ovule and development of fruit containing seeds.[42] It may arise terminally on a shoot or from the axil of a leaf.[43] The flower-bearing part of the plant is usually sharply distinguished from the leaf-bearing part, and forms a branch-system called an inflorescence.

Flowers produce two kinds of reproductive cells. Microspores, which divide to become pollen grains, are the male cells; they are borne in the stamens.[44] The female cells, megaspores, divide to become the egg cell. They are contained in the ovule and enclosed in the carpel; one or more carpels form the pistil.

The flower may consist only of these parts, as in wind-pollinated plants like the willow, where each flower comprises only a few stamens or two carpels. In insect- or bird-pollinated plants, other structures protect the sporophylls and attract pollinators. The individual members of these surrounding structures are known as sepals and petals (or tepals in flowers such as Magnolia where sepals and petals are not distinguishable from each other). The outer series (calyx of sepals) is usually green and leaf-like, and functions to protect the rest of the flower, especially the bud. The inner series (corolla of petals) is, in general, white or brightly colored, is more delicate in structure, and attracts pollinators by colour, scent, and nectar.

Most flowers are hermaphroditic, producing both pollen and ovules in the same flower, but some use other devices to reduce self-fertilization. Heteromorphic flowers have carpels and stamens of differing lengths, so animal pollinators cannot easily transfer pollen between them. Homomorphic flowers may use a biochemical self-incompatibility to discriminate between self and non-self pollen grains. Dioecious plants such as holly have male and female flowers on separate plants.[45] Monoecious plants have separate male and female flowers on the same plant; these are often wind-pollinated,[46] as in maize,[47] but include some insect-pollinated plants such as Cucurbita squashes.[48]

Fertilisation and embryogenesis

See main article: Plant embryogenesis.

Double fertilization requires two sperm cells to fertilise cells in the ovule. A pollen grain sticks to the stigma at the top of the pistil, germinates, and grows a long pollen tube. A haploid generative cell travels down the tube behind the tube nucleus. The generative cell divides by mitosis to produce two haploid (n) sperm cells. The pollen tube grows from the stigma, down the style and into the ovary. When it reaches the micropyle of the ovule, it digests its way into one of the synergids, releasing its contents including the sperm cells. The synergid that the cells were released into degenerates; one sperm makes its way to fertilise the egg cell, producing a diploid (2n) zygote. The second sperm cell fuses with both central cell nuclei, producing a triploid (3n) cell. The zygote develops into an embryo; the triploid cell develops into the endosperm, the embryo's food supply. The ovary develops into a fruit. and each ovule into a seed.[49]

Fruit and seed

See main article: Fruit and Seed.

As the embryo and endosperm develop, the wall of the embryo sac enlarges and combines with the nucellus and integument to form the seed coat. The ovary wall develops to form the fruit or pericarp, whose form is closely associated with type of seed dispersal system.[50]

Other parts of the flower often contribute to forming the fruit. For example, in the apple, the hypanthium forms the edible flesh, surrounding the ovaries which form the tough cases around the seeds.[51]

Apomixis, setting seed without fertilization, is found naturally in about 2.2% of angiosperm genera.[52] Some angiosperms, including many citrus varieties, are able to produce fruits through a type of apomixis called nucellar embryony.[53]

Adaptive function of flowers

Charles Darwin in his 1878 book The Effects of Cross and Self-Fertilization in the Vegetable Kingdom[54] in the initial paragraph of chapter XII noted "The first and most important of the conclusions which may be drawn from the observations given in this volume, is that generally cross-fertilisation is beneficial and self-fertilisation often injurious, at least with the plants on which I experimented." Flowers emerged in plant evolution as an adaptation for the promotion of cross-fertilisation (outcrossing), a process that allows the masking of deleterious mutations in the genome of progeny. The masking effect is known as genetic complementation.[55] This beneficial effect of cross-fertilisation on progeny is also referred to as hybrid vigor or heterosis. Once flowers became established in a lineage as an evolutionary adaptation to promote cross-fertilization, subsequent switching to inbreeding usually becomes disadvantageous, in large part because it allows expression of the previously masked deleterious recessive mutations, i.e. inbreeding depression.

Also, Meiosis in flowering plants provides a direct mechanism for repairing DNA through genetic recombination in reproductive tissues.[56] Sexual reproduction appears to be required for maintaining long-term genomic integrity and only infrequent combinations of extrinsic and intrinsic factors permit shifts to asexuality.[56] Thus the two fundamental aspects of sexual reproduction in flowering plants, cross-fertilization (outcrossing) and meiosis appear to be maintained respectively by the advantages of genetic complementation and recombinational repair.[55]

Interactions with humans

See main article: Human uses of plants.

Practical uses

Agriculture is almost entirely dependent on angiosperms, which provide virtually all plant-based food and livestock feed. Much of this food derives from a small number of flowering plant families.[57] For instance, half of the world's calorie intake is supplied by just three plants - wheat, rice and maize.[58]

Major food-providing families
Family English Example foods from that family
Grasses, cereals Most feedstocks, inc. rice, maize, wheat, barley, rye, oats, pearl millet, sugar cane, sorghum
Legumes, pea family Peas, beans, lentils; for animal feed, clover, alfalfa
Nightshade family Potatoes, tomatoes, peppers, aubergines
Gourd family Squashes, cucumbers, pumpkins, melons
Cabbage family Cabbage and its varieties, e.g. Brussels sprout, broccoli; mustard; oilseed rape
Parsley family Parsnip, carrot, parsley, coriander, fennel, cumin, caraway
Rue family[59] Oranges, lemons, grapefruits
Rose family[60] Apples, pears, cherries, apricots, plums, peaches

Flowering plants provide a diverse range of materials in the form of wood, paper, fibers such as cotton, flax, and hemp, medicines such as digoxin and opioids, and decorative and landscaping plants. Coffee and hot chocolate are beverages from flowering plants.[57]

Cultural uses

Both real and fictitious plants play a wide variety of roles in literature and film.[61] Flowers are the subjects of many poems by poets such as William Blake, Robert Frost, and Rabindranath Tagore.[62] Bird-and-flower painting is a kind of Chinese painting that celebrates the beauty of flowering plants.[63] Flowers have been used in literature to convey meaning by authors including William Shakespeare.[64] Flowers are used in a variety of art forms which arrange cut or living plants, such as bonsai, ikebana, and flower arranging. Ornamental plants have sometimes changed the course of history, as in tulipomania.[65] Many countries and regions have floral emblems; a survey of 70 of these found that the most popular flowering plant family for such emblems is Orchidaceae at 15.7% (11 emblems), followed by Fabaceae at 10% (7 emblems), and Asparagaceae, Asteraceae, and Rosaceae all at 5.7% (4 emblems each).[66]

Conservation

Human impact on the environment has driven a range of species extinct and is threatening even more today. Multiple organizations such as IUCN and Royal Botanic Gardens, Kew suggest that around 40% of plant species are threatened with extinction.[67] The majority are threatened by habitat loss, but activities such as logging of wild timber trees and collection of medicinal plants, or the introduction of non-native invasive species, also play a role.

Relatively few plant diversity assessments currently consider climate change, yet it is starting to impact plants as well. About 3% of flowering plants are very likely to be driven extinct within a century at 2C-change of global warming, and 10% at 3.2C-change.[68] In worst-case scenarios, half of all tree species may be driven extinct by climate change over that timeframe.

Conservation in this context is the attempt to prevent extinction, whether in situ by protecting plants and their habitats in the wild, or ex situ in seed banks or as living plants.[69] Some 3000 botanic gardens around the world maintain living plants, including over 40% of the species known to be threatened, as an "insurance policy against extinction in the wild."[70] The United Nations' Global Strategy for Plant Conservation asserts that "without plants, there is no life". It aims to "halt the continuing loss of plant diversity" throughout the world.[71]

Bibliography

Articles, books and chapters

Websites

Notes and References

  1. Book: Lindley, J. . 1830 . Introduction to the Natural System of Botany . London . Longman, Rees, Orme, Brown, and Green . xxxvi . true . 29 January 2018 . 27 August 2017 . https://web.archive.org/web/20170827171755/http://www.biodiversitylibrary.org/item/31944#page/21/mode/1up . live .
  2. Cantino . Philip D. . Doyle . James A. . Graham . Sean W. . Judd . Walter S. . Olmstead . Richard G. . Soltis . Douglas E. . Douglas E. Soltis . Soltis . Pamela S. . Pamela S. Soltis . Donoghue . Michael J. . 3 . 2007 . Towards a phylogenetic nomenclature of Tracheophyta . Taxon . 56 . 3 . E1–E44 . 10.2307/25065865. 25065865 .
  3. Christenhusz . M. J. M. . Byng . J. W. . 2016 . The number of known plants species in the world and its annual increase . Phytotaxa . 261 . 201–217 . 10.11646/phytotaxa.261.3.1 . 3 . free . 21 February 2022 . 6 April 2017 . https://web.archive.org/web/20170406045346/http://biotaxa.org/Phytotaxa/article/download/phytotaxa.261.3.1/20598 . live .
  4. Web site: Angiosperms OpenStax Biology 2e . 19 July 2021 . courses.lumenlearning.com . 19 July 2021. https://web.archive.org/web/20210719225359/https://courses.lumenlearning.com/suny-osbiology2e/chapter/angiosperms/ . live.
  5. Friedman . William E. . Ryerson . Kirsten C. . Reconstructing the ancestral female gametophyte of angiosperms: Insights from Amborella and other ancient lineages of flowering plants . American Journal of Botany . 96 . 1 . 2009 . 10.3732/ajb.0800311 . 129–143. 21628180 .
  6. Book: Raven, Peter H. . Evert, Ray F. . Eichhorn, Susan E. . Biology of Plants . registration . 2005 . W. H. Freeman . 978-0-7167-1007-3 . 376–.
  7. Williams . Joseph H. . The evolution of pollen germination timing in flowering plants: Austrobaileya scandens (Austrobaileyaceae) . AoB Plants . 2012 . pls010 . 2012 . 22567221 . 3345124 . 10.1093/aobpla/pls010 .
  8. Baroux . C. . Spillane . C. . Grossniklaus . U. . Evolutionary origins of the endosperm in flowering plants . Genome Biology . 3 . reviews1026.1 . 2002 . 9 . reviews1026.1 . 10.1186/gb-2002-3-9-reviews1026 . 12225592 . 139410 . free .
  9. Gonçalves . Beatriz . Case not closed: the mystery of the origin of the carpel . EvoDevo . 12 . 1 . 2021-12-15 . 14 . 2041-9139 . 10.1186/s13227-021-00184-z . 34911578 . 8672599 . free .
  10. Book: Baas, Pieter . New Perspectives in Wood Anatomy . Systematic, phylogenetic, and ecological wood anatomy — History and perspectives . Forestry Sciences . Springer Netherlands . Dordrecht . 1982 . 1 . 978-90-481-8269-5 . 0924-5480 . 10.1007/978-94-017-2418-0_2 . 23–58.
  11. Web site: Menara, yellow meranti, Shorea . Guinness World Records . 6 January 2019 . 8 May 2023 . yellow meranti (Shorea faguetiana) ... 98.53 m (323 ft 3.1 in) tall ... swamp gum (Eucalyptus regnans) ... In 2014, it had a tape-drop height of 99.82 m (327 ft 5.9 in).
  12. Web site: 2009-11-25 . The Charms of Duckweed . 2022-07-05 . https://web.archive.org/web/20091125213317/http://www.mobot.org/jwcross/duckweed/duckweed.htm . 25 November 2009 .
  13. Leake . J.R. . 1994 . The biology of myco-heterotrophic ('saprophytic') plants . New Phytologist . 127 . 2 . 171–216 . 10.1111/j.1469-8137.1994.tb04272.x . 33874520 . 85142620 .
  14. Westwood . James H. . Yoder . John I. . Timko . Michael P. . dePamphilis . Claude W. . The evolution of parasitism in plants . Trends in Plant Science . 15 . 4 . 2010 . 1360-1385 . 10.1016/j.tplants.2010.01.004 . 227–235. 20153240 . 2010TPS....15..227W .
  15. Web site: Angiosperms . University of Nevada, Las Vegas . 6 May 2023.
  16. Book: Kendrick . Gary A. . Orth . Robert J. . Sinclair . Elizabeth A. . Statton . John . Plant Regeneration from Seeds . Effect of climate change on regeneration of seagrasses from seeds . 2022 . 10.1016/b978-0-12-823731-1.00011-1 . 275–283 . 978-0-1282-3731-1 .
  17. Karlsson . P. S. . Pate . J. S. . Contrasting effects of supplementary feeding of insects or mineral nutrients on the growth and nitrogen and phosphorous economy of pygmy species of Drosera. . Oecologia . 1992 . 92 . 1 . 8–13 . 10.1007/BF00317256 . 28311806 . 1992Oecol..92....8K . 13038192 .
  18. Book: Pardoe, H. S. . Mountain Plants of the British Isles . 1995 . . 24 . 978-0-7200-0423-6 .
  19. Hart . Robin . Why are Biennials so Few? . . 1977 . 111 . 980 . 792–799 . 10.1086/283209 . 2460334 . 85343835 .
  20. Rowe . Nick . Speck . Thomas . Plant growth forms: an ecological and evolutionary perspective . New Phytologist . 166 . 1 . 2005-01-12 . 0028-646X . 10.1111/j.1469-8137.2004.01309.x . 61–72 . 15760351 . free .
  21. Thorne . R.F. . How many species of seed plants are there?. Taxon. 51 . 511–522 . 2002. 10.2307/1554864 . 3 . 1554864.
  22. Scotland . R. W. . Wortley . A. H. . How many species of seed plants are there? . Taxon . 52 . 101–104. 2003 . 10.2307/3647306 . 1 . 3647306.
  23. Govaerts . R. . How many species of seed plants are there? – a response . Taxon . 52 . 3 . 583–584 . 2003 . 10.2307/3647457 . 3647457. free .
  24. Goffinet . Bernard . Buck . William R. . 2004 . Systematics of the Bryophyta (Mosses): From molecules to a revised classification . Monographs in Systematic Botany . 98 . 205–239 .
  25. Book: Raven . Peter H. . Evert . Ray F. . Eichhorn . Susan E. . 2005 . Biology of Plants . 7th . New York . . 0-7167-1007-2 .
  26. Web site: Stevens . P. F. . 2011 . Angiosperm Phylogeny Website (at Missouri Botanical Garden) . 21 February 2022 . 20 January 2022 . https://web.archive.org/web/20220120065914/http://www.mobot.org/mobot/research/apweb/welcome.html . live.
  27. Web site: Kew Scientist 30. October 2006. https://web.archive.org/web/20070927005410/https://www.kew.org/kewscientist/ks_30.pdf. 27 September 2007.
  28. Book: Brown, Robert . Character and description of Kingia, a new genus of plants found on the southwest coast of New Holland: with observations on the structure of its unimpregnated ovulum; and on the female flower of Cycadeae and Coniferae . 534–565 . . King, Philip Parker . Narrative of a Survey of the Intertropical and Western Coasts of Australia: Performed Between the Years 1818 and 1822 . 1827 . J. Murray . 185517977 .
  29. Buggs . Richard J.A. . January 2021 . The origin of Darwin's "abominable mystery" . American Journal of Botany . 108 . 1 . 22–36 . 10.1002/ajb2.1592 . 33482683 . 231689158 . free .
  30. As easy as APG III – Scientists revise the system of classifying flowering plants . The Linnean Society of London . 2 October 2009 . 8 October 2009 . https://web.archive.org/web/20101126092206/https://www.linnean.org/index.php?id=448 . 26 November 2010.
  31. Leebens-Mack . M. . Barker . M. . Carpenter . E. . Michael Deyholos . Deyholos . M. K. . Gitzendammer . M. A. . Graham . S.W. . Grosse . I. . Li . Zheng . 3 . One thousand plant transcriptomes and the phylogenomics of green plants . Nature . 574 . 7780 . 2019 . 679–685 . 10.1038/s41586-019-1693-2 . 31645766 . 6872490 . free .
  32. Guo . Xing . Chloranthus genome provides insights into the early diversification of angiosperms . Nature Communications . 26 November 2021 . 12 . 1 . 6930 . 10.1038/s41467-021-26922-4 . 34836973 . 8626473 . 2021NatCo..12.6930G . free .
  33. Zuntini . Alexandre R. . Carruthers . Tom . Maurin . Olivier . Bailey . Paul C. . Leempoel . Kevin . Brewer . Grace E. . etal . Phylogenomics and the rise of the angiosperms . . 24 April 2024 . 629 . 8013 . 843–850 . 0028-0836 . 10.1038/s41586-024-07324-0. 38658746 . 11111409 . 2024Natur.629..843Z .
  34. Edwards . D. . The role of mid-palaeozoic mesofossils in the detection of early bryophytes . Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences . 355 . 1398 . 733–54; discussion 754–5 . June 2000 . 10905607 . 1692787 . 10.1098/rstb.2000.0613 .
  35. Herendeen . Patrick S. . Friis . Else Marie . Pedersen . Kaj Raunsgaard . Crane . Peter R. . 2017-03-03 . Palaeobotanical redux: revisiting the age of the angiosperms . Nature Plants . 3 . 3 . 17015 . 10.1038/nplants.2017.15 . 28260783 . 205458714 . 2055-0278.
  36. Friedman . William E. . January 2009 . The meaning of Darwin's "abominable mystery" . American Journal of Botany . 96 . 1 . 5–21 . 10.3732/ajb.0800150 . 21628174.
  37. Bateman . Richard M . 2020-01-01 . Ort . Donald . Hunting the Snark: the flawed search for mythical Jurassic angiosperms . Journal of Experimental Botany . en . 71 . 1 . 22–35 . 10.1093/jxb/erz411 . 31538196 . 0022-0957.
  38. Stull . Gregory W. . Qu . Xiao-Jian . Parins-Fukuchi . Caroline . Yang . Ying-Ying . Yang . Jun-Bo . Yang . Zhi-Yun . Hu . Yi . Ma . Hong . Soltis . Pamela S. . Soltis . Douglas E. . Li . De-Zhu . 3 . July 19, 2021 . Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms . Nature Plants . 7. 8 . 1015–1025 . 10.1038/s41477-021-00964-4 . 34282286 . 236141481 . 10 January 2022 . 10 January 2022 . https://web.archive.org/web/20220110174725/https://www.nature.com/articles/s41477-021-00964-4/ . live.
  39. Sauquet . Hervé . Ramírez-Barahona . Santiago . Magallón . Susana . 2022-06-24 . Melzer . Rainer . What is the age of flowering plants? . Journal of Experimental Botany . en . 73 . 12 . 3840–3853 . 10.1093/jxb/erac130 . 35438718 . 0022-0957.
  40. Book: Sadava . David . Heller . H. Craig . Orians . Gordon H. . Purves . William K. . Hillis . David M. . 3 . Life: the science of biology . 4 August 2010 . December 2006 . Macmillan . 978-0-7167-7674-1 . 477– . 23 December 2011 . https://web.archive.org/web/20111223082952/http://books.google.com/books?id=1m0_FLEjd-cC&pg=PA477. live.
  41. Book: Stewart . Wilson Nichols . Rothwell . Gar W. . Paleobotany and the evolution of plants . 2nd . . 1993 . 498 . 978-0-521-23315-6 .
  42. Willson . Mary F. . 1 June 1979 . Sexual Selection in Plants . . 113 . 6 . 777–790 . 10.1086/283437 . 84970789 . 9 November 2021 . 9 November 2021 . https://web.archive.org/web/20211109164204/https://www.journals.uchicago.edu/doi/10.1086/283437. live.
  43. Book: Bredmose, N. . Encyclopedia of Rose Science . Growth Regulation: Axillary Bud Growth . Elsevier . 2003 . 10.1016/b0-12-227620-5/00017-3 . 374–381. 9780122276200 .
  44. Book: Salisbury . Frank B. . Sexual Reproduction . 1970 . Vascular Plants: Form and Function . 185–195 . Salisbury . Frank B. . Fundamentals of Botany Series . London . Macmillan Education . 10.1007/978-1-349-00364-8_13 . 978-1-349-00364-8 . Parke . Robert V. . Parke . Robert V..
  45. Ainsworth . C. . August 2000 . Boys and Girls Come Out to Play: The Molecular Biology of Dioecious Plants . Annals of Botany . 86 . 2 . 211–221 . 10.1006/anbo.2000.1201 . free.
  46. Book: Batygina, T.B. . Embryology of Flowering Plants: Terminology and Concepts, Vol. 3: Reproductive Systems . 2019 . CRC Press . 978-1-4398-4436-6 . 43.
  47. Bortiri . E. . Hake . S. . Flowering and determinacy in maize . Journal of Experimental Botany . Oxford University Press (OUP) . 58 . 5 . 2007-01-13 . 0022-0957 . 10.1093/jxb/erm015 . 909–916. 17337752 .
  48. Book: Mabberley, D. J. . 2008 . The Plant Book: A Portable Dictionary of the Vascular Plants . Cambridge University Press . Cambridge . 978-0-521-82071-4 . 235.
  49. Berger . F. . January 2008 . Double-fertilization, from myths to reality . Sexual Plant Reproduction . 21 . 1 . 3–5 . 10.1007/s00497-007-0066-4 . 8928640 .
  50. Eriksson . O. . Evolution of Seed Size and Biotic Seed Dispersal in Angiosperms: Paleoecological and Neoecological Evidence . International Journal of Plant Sciences . 169 . 7 . 863–870 . 2008 . 10.1086/589888 . 52905335 .
  51. Web site: Fruit Anatomy . University of California . Fruit & Nut Research & Information Center . live . https://web.archive.org/web/20230502175636/https://ucanr.edu/sites/btfnp/generaltopics/AnatomyPollination/Fruit_Anatomy/ . 2 May 2023.
  52. Hojsgaard . D. . Klatt . S. . Baier . R. . Carman . J.G. . Hörandl . E. . 3 . Taxonomy and Biogeography of Apomixis in Angiosperms and Associated Biodiversity Characteristics . Critical Reviews in Plant Sciences . 33 . 5 . 414–427 . September 2014 . 27019547 . 4786830 . 10.1080/07352689.2014.898488 . 2014CRvPS..33..414H .
  53. Book: Gentile, Alessandra . The Citrus Genome . 18 March 2020 . Springer Nature . 978-3-030-15308-3 . 171 . 13 December 2020 . 14 April 2021 . https://web.archive.org/web/20210414224058/https://books.google.com/books?id=hsPXDwAAQBAJ . live.
  54. Darwin, C. R. 1878. The effects of cross and self fertilisation in the vegetable kingdom. London: John Murray". darwin-online.org.uk
  55. Bernstein H, Byerly HC, Hopf FA, Michod RE. Genetic damage, mutation, and the evolution of sex. Science. 1985 Sep 20;229(4719):1277-81. doi: 10.1126/science.3898363. PMID 3898363
  56. Hörandl E. Apomixis and the paradox of sex in plants. Ann Bot. 2024 Mar 18:mcae044. doi: 10.1093/aob/mcae044. Epub ahead of print. PMID 38497809
  57. Web site: Dilcher . David L. . Cronquist . Arthur . Zimmermann . Martin Huldrych . Stevens . Peter . Stevenson . Dennis William . Berry . Paul E. . Arthur Cronquist . Peter F. Stevens . Angiosperm: Significance to Humans . . 8 March 2016.
  58. News: McKie . Robin . 16 July 2017 . Maize, rice, wheat: alarm at rising climate risk to vital crops . The Observer . 30 July 2023 .
  59. Web site: Rutaceae . live . https://web.archive.org/web/20190719224511/https://www.botanical-dermatology-database.info/BotDermFolder/RUTA.html . July 19, 2019 . Botanical Dermatology Database.
  60. Zhang . Shu-Dong . Jin . Jian-Jun . Chen . Si-Yun . Chase . Mark W. . Soltis . Douglas E. . Li . Hong-Tao . Yang . Jun-Bo . Li . De-Zhu . Yi . Ting-Shuang . 3 . 2017 . Diversification of Rosaceae since the Late Cretaceous based on plastid phylogenomics . New Phytologist . 214 . 3 . 1355–1367 . 10.1111/nph.14461 . 28186635 . 1469-8137. free .
  61. Literary Plants . Nature Plants . 2015 . 1 . 11 . 15181 . 10.1038/nplants.2015.181 . 27251545 . free .
  62. Web site: Flower Poems . Poem Hunter . 21 June 2016.
  63. Web site: Nature's Song: Chinese Bird and Flower Paintings . 2022-08-04 . Museum Wales . en . 4 August 2022 . https://web.archive.org/web/20220804231344/https://museum.wales/cardiff/whatson/9245/Natures-Song-Traditional-Chinese-Bird-and-Flower-Paintings-/ . dead .
  64. Web site: The Language of Flowers . Folger Shakespeare Library . 2013-05-31 . https://web.archive.org/web/20140919185926/http://www.folger.edu/template.cfm?cid=3192 . 2014-09-19 . dead.
  65. Web site: Lambert . Tim . A Brief History of Gardening . . 21 June 2016 . 2014.
  66. Book: Lim . Reuben . Tan . Heok . Tan . Hugh . 2013 . Official Biological Emblems of the World . . Singapore . 978-9-8107-4147-1 .
  67. Lughadha . Eimear Nic. Bachman . Steven P. . Leão . Tarciso C. C. . Forest . Félix . Halley . John M. . Moat . Justin . Acedo. Carmen . Bacon . Karen L. . Brewer . Ryan F. A. . Gâteblé . Gildas . Gonçalves . Susana C.. Govaerts . Rafaël . Hollingsworth . Peter M. . Krisai-Greilhuber . Irmgard . de Lirio . Elton J. . Moore . Paloma G. P. . Negrão . Raquel . Onana . Jean Michel . Rajaovelona . Landy R. . Razanajatovo . Henintsoa . Reich . Peter B. . Richards . Sophie L. . Rivers . Malin C. . Cooper . Amanda . Iganci . João . Lewis . Gwilym P. . Smidt . Eric C. . Antonelli . Alexandre . Mueller . Gregory M. . Walker . Barnaby E. . 29 September 2020 . Extinction risk and threats to plants and fungi . Plants People Planet . 2 . 5 . 389–408 . 10.1002/ppp3.10146 . 225274409 . free . 10316/101227 . free .
  68. Parmesan, C., M.D. Morecroft, Y. Trisurat et al. (2022) Chapter 2: Terrestrial and Freshwater Ecosystems and Their Services in Book: Climate Change 2022 – Impacts, Adaptation and Vulnerability . Terrestrial and Freshwater Ecosystems and Their Services . Cambridge University Press . 2023 . 978-1-009-32584-4 . 10.1017/9781009325844.004 . 197–378 .
  69. Web site: Botanic Gardens and Plant Conservation . Botanic Gardens Conservation International . 19 July 2023.
  70. Web site: Plant Conservation Around the World . Cambridge University Botanic Garden . 19 July 2023 . 2020.
  71. Web site: Updated Global Strategy for Plant Conservation 2011-2020 . Convention on Biological Diversity . 19 July 2023 . 3 July 2023.

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