Thymelaeaceae
![]() | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (November 2017) |
Thymelaeaceae | |
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Thymelaea hirsuta | |
Scientific classification ![]() | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Malvales |
Family: | Thymelaeaceae Juss. |
Genera | |
See text |
The Thymelaeaceae /ˌθɪmɪliːˈeɪsiː/ are a cosmopolitan family of flowering plants composed of 50 genera (listed below) and 898 species.[1] It was established in 1789 by Antoine Laurent de Jussieu.[2] The Thymelaeaceae are mostly trees and shrubs, with a few vines and herbaceous plants.
Description
Several conspicuous or unusual traits are characteristic of the family (when Tepuianthus is excluded). The bark is usually shiny and fibrous, with strips of bark peeling down the side of broken stems.
Thymelaeaceae are often difficult to identify because of equivocal interpretation of the flower parts. Sepals, petals, and staminodes are hard to distinguish, and many keys are ambiguous about whether staminodes should be counted as stamens. Moreover, in Wikstroemia, individual plants often produce anomalous flowers.
Taxonomy
The family is named for the genus Thymelaea, the name of which is a combination of the Greek name for the herb thyme θύμος (thúmos) and that for the olive ἐλαία (elaía) - in reference to its thyme-like foliage (i.e. minuscule leaves) and olive-like fruit.[4]
Classification
The Thymelaeaceae are in the order Malvales.[5] Except for a sister relationship with Tepuianthaceae, little is known for sure about their relationships with the other families in the order.[6]
Unlike most recent authors, who recognize four
Octolepidoideae
- Octolepis group: Arnhemia, Deltaria, Lethedon, Octolepis, Solmsia
- Gonystylus group: Aetoxylon, Amyxa, Gonystylus
Thymelaeoideae
- Synandrodaphneae: Synandrodaphne
- Aquilarieae: Aquilaria, Gyrinops
- Daphneae
- Linostoma group:
- Phaleria group: Peddiea, Phaleria
- Daphne group: Daphne, Daphnopsis, Diarthron, Dirca, Edgeworthia, Funifera, Goodallia, Lagetta, Ovidia, Rhamnoneuron, Schoenobiblus, Stellera, Thymelaea, Wikstroemia
- Gnidia group: Dais, Drapetes, Gnidia, Kelleria, Lachnaea, Passerina, Pimelea, Struthiola
- Incertae sedis: Linodendron, Stephanodaphne, Lasiadenia
Phylogeny
The first molecular phylogeny for Thymelaeaceae was published in 2002.
The tree below is an excerpt from the Rautenbach (2002) phylogeny. The species of Gnidia were chosen from among the most common or well known species in a way that shows which clades contain species of Gnidia.
Thymelaeoideae |
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Defining the genera
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/9b/Ruby_Gnidia_%28Gnidia_rubescens%29_close-up_%2811421758284%29.jpg/170px-Ruby_Gnidia_%28Gnidia_rubescens%29_close-up_%2811421758284%29.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Gnidia_pinifolia_Bettys_Bay.jpg/170px-Gnidia_pinifolia_Bettys_Bay.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Gnidia_glauca_%286666724377%29.jpg/170px-Gnidia_glauca_%286666724377%29.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Nacchinar_%28in_Tamil%29_%283127220503%29.jpg/170px-Nacchinar_%28in_Tamil%29_%283127220503%29.jpg)
The circumscription of genera in Thymelaeaceae has always been especially difficult, and is to some degree artificial. For example, the difficulty of distinguishing Daphne from Wikstroemia has been commented upon by Rautenbach and Herber.[8][9] Several small genera are probably embedded in Daphne or Wikstroemia, or if Daphne and Wikstroemia are intermingled, these small genera might be embedded in both simultaneously. Stellera, for example, is nested within Wikstroemia, at least (see the phylogenetic tree below).
A recent comparison of DNA sequences has established the monophyly of Thymelaea and the polyphyly of Diarthron,[10] but there was not sufficient sampling in Wikstroemia and Daphne to exclude the possibility that Thymelaea, Diarthron, and others might be embedded in them.
The large genus Gnidia is polyphyletic and its species fall into 4 separate clades, each of which contains other genera of the family (see the phylogenetic tree below). The type species for Gnidia is Gnidia pinifolia. If Gnidia is divided into 4 or more separate genera, the segregate genus which contains G. pinifolia will retain the name Gnidia. Zachary S. Rogers published a revision of the Gnidia of Madagascar in 2009 in Annals of the Missouri Botanical Garden.
Some of the older treatments of Thymelaeaceae recognize Lasiosiphon as a separate genus from Gnidia. This distinction was later shown to be artificial. However, Van der Bank et al. (2002)[7] suggested that Lasiosiphon might be resurrected if redefined. The type species for Lasiosiphon is Gnidia glauca, formerly known as Lasiosiphon glaucus.
Open questions
Rautenbach used different names from Herber for some of the groups and placed some of the groups at different taxonomic rank, but her phylogeny supports Herber's classification with the few exceptions noted below. The only strongly supported difference (99% (bootstrap percentage) from Herber's classification was that Dais was found to be sister to Phaleria. The phylogeny casts significant doubt upon the monophyly of the subfamily Octolepidoideae, and upon the monophyly of the informal Octolepis and Gonostylus groups, but this result had only weak statistical support. Only a sampling of more species and more DNA from each will determine whether these groups are monophyletic or not. Stephanodaphne and Peddiea might need to be transferred to the Gnidia group, but support was not strong (60% BP) for a clade consisting of the Gnidia group with Stephanodaphne and Peddiea. Again, more extensive sampling will be required to resolve this question. Two of the 3 genera placed incertae sedis by Herber (Linodendron and Lasiadenia) have not yet been sampled and their relationships to other genera remain obscure.
Genera
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Gonystylus_bancanus.jpg/170px-Gonystylus_bancanus.jpg)
Herber (2003)[9] recognized 45 genera, excluding Tepuianthus from the family, sinking Atemnosiphon and Englerodaphne into Gnidia, Eriosolena into Daphne, and Thecanthes into Pimelea.[9] The largest genera and the approximate number of species in each are Gnidia (160), Pimelea (110), Daphne (95), Wikstroemia (70), Daphnopsis (65), Struthiola (35), Lachnaea (30), Thymelaea (30), Phaleria (30), and Gonystylus (25).[9]
As of December 2014[update], 50+ genera are accepted by the World Checklist of Thymelaceae:[11]
In the past, different authors have defined Thymelaeaceae in different ways. For example,
Distribution
The family is more diverse in the Southern Hemisphere than in the Northern, with major concentrations of species in Africa and Australia.[15] The genera are overwhelmingly African.[16]
Ethnobotany and economic use
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/98/Hooker-Lagetta_lagetto.jpg/170px-Hooker-Lagetta_lagetto.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/2/20/Jamaican-lacebark-souvenirs2.jpg/170px-Jamaican-lacebark-souvenirs2.jpg)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Flickr_-_BioDivLibrary_-_n39_w1150_%281%29.jpg/170px-Flickr_-_BioDivLibrary_-_n39_w1150_%281%29.jpg)
Several genera are of economic importance. Gonystylus (Ramin) is valued for its comparatively soft, easily worked yellowish wood, but trade in all species in the genus are controlled by CITES. Many genera have inner bark yielding strong fibre suitable for the making of cordage and paper - a fact actually acknowledged in the naming of one of the genera, Funifera being the Latin for "bearer (provider) of rope". The barks of Daphne, Edgeworthia, Rhamnoneuron, Thymelaea, Stellera, and Wikstroemia are used in paper-making, while Lagetta species are known as lacebark for their lacelike inner bark, the attractive appearance of which has led to their being used to make clothing and other utilitarian objects.
Toxicity and medicinal uses
Many of the species (e.g.
Use as ornamental plants
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Daphne_bholua_%283307537340%29.jpg/170px-Daphne_bholua_%283307537340%29.jpg)
Daphne is grown (despite the high toxicity of its attractive fruits) for its sweetly scented flowers. Species of Wikstroemia, Daphne, Phaleria, Dais, Pimelea and other genera are grown as ornamentals.[18][8]
Gallery
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Inflorescence of the Australian Pimelea spectabilis.
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Flowers of an unidentified Passerina species.
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Flower of Daphnopsis racemosa.
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Fruits of Daphnopsis racemosa.
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Flowers of Dirca palustris of the US
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Edgeworthia chrysantha, native to China.
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Flowers of the Hawaiian Wikstroemia phillyreifolia.
References
- ^ Zachary S. Rogers (2009 onwards). A World Checklist of Thymelaeaceae (version 1). Missouri Botanical Garden Website, St. Louis.
- ^ Antoine Laurent de Jussieu Genera Plantarum, page 76. Herrisant & Barrois, Paris.
- ^ Ernst Schmidt, Mervyn Lotter and Warren McCleland Trees and Shrubs of Mpumalanga and Kruger National Park (2002), p. 448, at Google Books
- ISBN 0-19-869106-8
- ^ Peter F. Stevens (2001 onwards) Angiosperm Phylogeny Website In: Missouri Botanical Garden Website
- ^ Clemens Bayer, Michael F. Fay, Anette Y. de Bruijn, Vincent Savolainen, Cynthia M. Morton, Klaus Kubitzki, William S. Alverson, and Mark W. Chase (1999). "Support for an expanded family concept of Malvaceae within a recircumscribed order Malvales: a combined analysis of plastid atpB and rbcL DNA sequences". Botanical Journal of the Linnean Society 129(4): 267-381
- ^ a b Michelle van der Bank, Michael F. Fay, and Mark W. Chase (2002). "Molecular Phylogenetics of Thymelaeaceae with particular reference to African and Australian genera". Taxon 51(2):329-339.
- ^ a b Marline Rautenbach. "Gnidia is not monophyletic: taxonomic implications for Gnidia and its relatives in Thymelaeoideae". Digispace at the University of Johannesburg 8 Jul 2008. (see External links below)
- ^ a b c d B.E. Herber. "Thymelaeaceae" In: The Families and Genera of Vascular Plants vol.V (Klaus Kubitzki and Clemens Bayer, volume editors). Springer-Verlag: Berlin, Heidelberg (2003)
- ^ David Galicia-Herbada (2006). "Origin and diversification of Thymelaea(Thymelaeaceae): inferences from a phylogenetic study based on ITS (rDNA) sequences". Plant Systematics and Evolution 257(3-4):159-187.
- ^ Rogers, Z.S. (2009). "A World Checklist of Thymelaeaceae (version 1)". Missouri Botanical Garden, St. Louis. Retrieved 26 November 2021.
- ^ Hutchinson,John. The Families of Flowering Plants, Third Edition (1973). Oxford University Press: London.
- ^ Horn,J.W., (2004). "The morphology and relationships of the Sphaerosepalaceae(Malvales)". Botanical Journal of the Linnean Society 144(1):1-40
- ^ Klaus Kubitzki. "Tepuianthaceae" In: The Families and Genera of Vascular Plants, vol.V Klaus Kubitzki and Clemens Bayer. (volume editors). Springer-Verlag: Berlin,Heidelberg. (2003).
- ^ Vernon H. Heywood, Richard K. Brummitt, Alastair Culham, and Ole Seberg. Flowering Plant Families of the World. Firefly Books: Ontario, Canada (2007)
- ^ Marline Rautenbach. Figure 1.2, page 7 In: "Gnidia is not monophyletic: taxonomic implications for Gnidia and its relatives in Thymelaeoideae" Digispace at the University of Johannesburg. 8 Jul 2008. (see External links below).
- S2CID 11550625.
- ISBN 978-1-58178-039-0.
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- Zachary S. Rogers (2009 onwards). A Worldwide Checklist of Thymelaeaceae (version 1).
- Angiosperm Phylogeny Peter F. Stevens (2001 onwards) In: Missouri Botanical Garden
- Rautenbach(2008) in: UJDigiSpace @ The University of Johannesburg
- distribution in: Gnidia is not monophyletic: taxonomic implications for Gnidia and its relatives in Thymelaeoideae
- Thymelaeaceae of Mongolia in FloraGREIF