Ranunculaceae

Ranunculaceae (buttercup or crowfoot family; Latin rānunculus "little frog", from rāna "frog") is a family of over 2,000 known species of flowering plants in 43 genera,[2] distributed worldwide.

Ranunculaceae
Temporal range: 145–0 Ma Early Cretaceous–Recent[1]
Ranunculus auricomus
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Ranunculales
Family: Ranunculaceae
Juss.
Type genus
Ranunculus
Subfamilies

The largest genera are Ranunculus (600 species), Delphinium (365), Thalictrum (330), Clematis (325), and Aconitum (300).

Description
Floral diagram. Adonis annua

Ranunculaceae are mostly herbaceous annuals or perennials, but some woody climbers (such as Clematis)[3] or shrubs (e.g. Xanthorhiza).

Most members of the family have bisexual flowers which can be showy or inconspicuous. Flowers are solitary, but are also found aggregated in cymes, panicles, or spikes. The flowers are usually radially symmetrical but are also found to be bilaterally symmetrical in the genera Aconitum and Delphinium.[4][5] The sepals, petals, stamens and carpels are all generally free (not fused), the outer flower segments typically number four or five. The outer stamens[lower-alpha 1] may be modified to produce only nectar, as in Aquilegia, Helleborus and Delphinium.[5]

In some genera, such as Thalictrum the sepals are colorful and appear petal-like (petaloid) and the petals can be inconspicuous or absent.[3] The stems are unarmed. The leaves are variable. Most species have both basal and cauline (stem) leaves, which are usually compound or lobed but can be simple. They are typically alternate, or occasionally opposite or even whorled. Many species, especially the perennials form rhizomes that develop new roots each year.[6] Ficaria verna can reproduce vegetatively by means of root tubers produced in the leaf axils.[3][4] Some members of the genus Thalictrum utilize anemophily while others utilize entomophily.[8] Flowers of the entomophilous genus Papaver, also of the Ranunculales order, produce only pollen.[9] Until recently, it was believed that the species of the genus Anemone also lack nectar.[10]

The fruits are most commonly free, unfused achenes (e.g. Ranunculus, Clematis) or follicles (e.g. Helleborus, Eranthis, Nigella), but a berry in Actaea.[3][4]

Fruit Morphology
Achene: Pulsatilla alpina
Achene: Ranunculus acris
Follicle: Nigella arvensis
Follicle: Helleborus niger

Phytochemistry

Ranunculaceae contain protoanemonin, which is toxic to humans and animals. Other poisonous or toxic compounds, alkaloids and glycosides, are also common.

Taxonomy

Takhtajan (1997) included the Ranunculaceae as the only family in the Ranunculales which he placed in a subclass, the Ranunculidae, instead of a superorder. Previously, Thorn (1992) placed the Ranunculaceae in the Berberidales, an order within the Superorder Magnolianae. Earlier Cronquist in 1981 included the Ranunculaceae along with seven other families in the Rancunculales which was included in the Magnoliidae, which he regarded as a subclass.[11] David, (2010)[12] placed the Ranuculaceae, together with the Eupteleaceae, Lardizabalaceae, Menispermaceae, Berberidaceae, and Papaveraceae in the Ranunculales, the only order in the superorder Ranunculanae. This follows the work of the Angiosperm Phylogeny Group.

The family Ranunculaceae sensu stricto (APG) is one of seven families included in the order Ranunculales within the eudicots according to the Angiosperm Phylogeny Group classification.[13] The family is monophyletic with Glaucidium as sister to the remaining genera.[14] This phylogeny is illustrated in the APG Poster.[15]

Subdivision

Early subdivisions of the family, such as Michel Adanson (1763), simply divided it based on one-seeded or many-seeded fruit. Prantl (1887) envisaged three tribes, Paeonieae, Hellebroreae and Anemoneae with Paeonia, Glaucidium and Hydrastis forming Paeonieae. By the twentieth century Langlet (1932) used chromosome types to create two subfamilies, Ranunculoideae and Thalictroideae. In 1966 Tamura further developed Langlet's system by adding floral characteristics with six subfamilies;

  • Helleboroideae
  • Ranunculoideae
  • Isopyroideae
  • Thalictroideae
  • Coptidoideae
  • Hydrastidoideae

but by 1988 he had reduced Coptidoideae to a tribe within Isopyroideae, leaving five subfamilies, an arrangement he continued in his 1993 monograph, dividing the larger subfamilies into tribes, though by then Paeonia and Glaucidium were no longer considered to belong to Ranunculaceae.[16] Paeonia was separated from Ranuculaceae and placed in its own family of Paeoniaceae (order Saxifragales). other genera originally included in Ranunculaceae include Circaeaster which was placed in its own family Circaeasteraceae.

Tamura's complete system was structured as follows;

Subfamilies and tribes
  • Subfamily Ranunculoideae Hutch.
    • Adonideae Kunth
    • Anemoneae DC.
    • Ranunculeae DC.
  • Subfamily Helleboroideae Hutch.
    • Helleboreae DC.
    • Cimicifugeae Torrey & A.Gray
    • Delphineae Schrödinger
    • Nigelleae Schrödinger
  • Subfamily Isopyroideae Tamura
    • Coptideae Langlet ex Tamura & K.Kosuge
    • Dichocarpeae Tamura & K.Kosuge
    • Isopyreae Schrödinger
  • Subfamily Thalictroideae
  • Subfamily Hydrastidoideae

The genus Glaucidium, having been moved to its own family (Glaucidiaceae), has since been restored to Ranuculaceae.

Molecular phylogenetics

When subjected to molecular phylogenetic analysis only Thalictroideae is monophyletic. The position of Glaucidium and some of its unique morphological characteristics prompted Stevens to suggest that it be given subfamilial rank as the monotypic Glaucidioideae. Similarly Hydrastis has been assigned to subfamily Hydrastidoideae.[17][14] Both genera are represented by a single species, Glaucidium palmatum and Hydrastis canadense respectively.

The relationships between the genera suggest the existence of three major clades corresponding to Coptidoideae, Thalictroideae (clade A) and Ranunculoideae (clade F). The latter is the largest with four subclades (B–E). Of these C corresponds to Delphineae, D to Cimicifugae and E to Ranunculoideae.[14] Consequently, Wang and colleagues (2009) proposed a new classification with five subfamilies, and further subdividing Ranunculoideae into ten tribes. The relationship between the subfamilies is shown in the cladogram;

In addition to the two monotypic subgenera, Coptoideae has 17 species and Thalictroideae has 450, including Thalictrum and Aquilegia. The other genera (2025 species, 81% of the family) belong to Ranunculoideae. Kingdonia had been included by Tamura in Anemoneae, but is now added to Circaeasteraceae.

Subfamilies of Ranunculaceae (5) and tribes of Ranunculoideae
  • Glaucidioideae (Tamura) Loconte (1)
  • Hydrastidoideae Engler (1)
  • Coptidoideae Tamura (2)
  • Thalictroideae Raf. (10)
  • Ranunculoideae Arn. (46)
    • Adonideae Kunth
    • Delphinieae Schröd.
    • Nigelleae Schröd.
    • Helleboreae DC.
    • Cimicifugeae Torr.and A.Gray
    • Caltheae Bercht .and J.Presl
    • Asteropyreae W.T.Wang and C. Y.Chang
    • Callianthemeae W.Wang and Z. D.Chen
    • Anemoneae DC.
    • Ranunculeae DC.
Cladogram of Ranunculaceae subfamilies[14]
Ranunculaceae
 

Glaucidoideae

 
 
 

Hydrastidoideae

 
 
 

Coptidoideae

 
 
 

Ranunculoideae

 
 

Thalictroideae

 
 
 
 
 

Genera

Ranunculaceae contains approximately 43 genera.[2][18]

Subfamily Glaucidioideae
Subfamily Hydrastidoideae
Subfamily Coptidoideae
Subfamily Thalictroideae
Subfamily Ranunculoideae
Tribe Adonideae
Tribe Delphinieae
Tribe Nigelleae
Tribe Helleboreae
Tribe Cimicifugeae
Tribe Caltheae
Tribe Asteropyreae
  • Asteropyrum J.R.Drumm. & Hutch.
Tribe Callianthemeae
Tribe Anemoneae
Tribe Ranunculeae

Previous genera

Fossil record

Fossils of fruits, pollen, seeds, and leaves are known from several dozen locations. The fossil record begins in the early Cretaceous and continues throughout the Tertiary. In most cases, the fossils are assigned to extant genera, or show a close relationship to a particular extant genus.[1]

Uses

Some Ranunculaceae are used as herbal medicines because of their alkaloids and glycosides, such as Hydrastis canadensis (goldenseal), whose root is used as a tonic. More than 30 species are used in homeopathy, including Aconitum napellus, Cimicifuga racemosa, Clematis recta, Clematis virginiana, Hydrastis canadensis, Ranunculus bulbosus, Helleborus niger, Delphinium staphisagria, Pulsatilla nigricans. Many genera are well known as cultivated flowers, such as Aconitum (monkshood), Clematis, Consolida (larkspur), Delphinium, Helleborus (Christmas rose), Trollius (globeflower). The seeds of Nigella sativa are used as a spice in Indian and Middle Eastern cuisine.[19]

Tribes of subfamily Ranunculoideae

Other subfamilies

See also

Notes
  1. In the Ranunculaceae, a variety of terms are used to describe the whorl of structures between the sepals and stamens, including honey-leaves, petals, staminodes or nectaries[6][7]

References
  1. Pigg & DeVore 2005.
  2. Christenhusz & Byng 2016.
  3. Clapham, Tutin & Warburg 1981.
  4. Stace 2010.
  5. Ronse de Craene 2010.
  6. FNA 2008
  7. Tamura 1993, p. 564.
  8. Steven, Janet; Waller, Donald (2004). "Reproductive alternatives to insect pollination in four species of Thalictrum (Ranunculaceae)". Plant Species Biology. 19 (2): 73–80. doi:10.1111/j.1442-1984.2004.00103.x. Retrieved 6 December 2018.
  9. Ross, Gary (22 December 2016). "Treat Your Bees to a Banquet of Poppies". Bee Culture. A.I. Root Company. Retrieved 6 December 2018.
  10. Erbar, Claudia; Leins, Peter (2013). "Nectar production in the pollen flower of Anemone nemorosa in comparison with other Ranunculaceae and Magnolia (Magnoliaceae)". Organisms Diversity & Evolution. 13 (3): 287–300. doi:10.1007/s13127-013-0131-9. S2CID 16275166. Retrieved 6 December 2018.
  11. Flowering Plant Gateway
  12. "Plants in their proper places – the new classification of flowering plants" (PDF). Royal Horticultural Society. Archived from the original (PDF) on 18 July 2011.
  13. APG 2016.
  14. Wang et al 2009.
  15. Angiosperm Phylogeny Poster
  16. Tamura 1993.
  17. Stevens 2017.
  18. The Plant List 2013, Ranunculaceae
  19. Turner 1984.

Bibliography
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.