An Introduction to the Subgeneric Classification of « Euphorbia » L., With Stress on the South African and Malagasy Species. I.

Croizat, Léon

doi:10.1080/00837792.1965.10669827

Cited by 29 publications

(10 citation statements)

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“…2) despite the very different vegetative appearance of the first and last from the typical spine-shield-bearing Euphorbia. The position that we found for E. corniculata and E. unicornis finally lays to rest the erroneous suspicion of Croizat (1972) and Leach (1976) that these two were more closely related to the Madagascan "christ thorns". The three species E. griseola, E. knuthii and E. mlanjeana, in which the cyathia have yellow glands and the capsules are strongly 3-angled, far exserted and pendulous, are shown to be closely allied by the ITS dataset (JK = 95 in Fig.…”

Section: Clade a -mentioning

confidence: 52%

A new subgeneric classification for Euphorbia (Euphorbiaceae) in southern Africa based on ITS and psbA-trnH sequence data

Bruyns

Mapaya

Hedderson

2006

TAXON

135

148

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We use data from the internal transcribed spacer (ITS) region of the nuclear rDNA cistron and the chloroplast psbA–trnH intergenic spacer to reconstruct the phylogenetic relationships among southern African species of Euphorbia. The results indicate that major re–organization is necessary of the groupings within Euphorbia that have been recognised in the past, since most of them turn out to be polyphyletic. Furthermore, in its present circumscription, Euphorbia itself is not monophyletic, nor do the southern African species form a monophyletic group. Both datasets show that the southern African species fall into four major groups, which we recognise as subgenera: Chamaesyce Raf., Esula Pers., Euphorbia and Rhizanthium (Boiss.) Wheeler. To accommodate the southern African species, subg. Chamaesyce is divided into sect. Chamaesyce, sect. Frondosae Bruyns, sect. nov., sect. Articulofruticosae Bruyns, sect. nov. and sect. Espinosae Pax & Hoffm. Subgenus Euphorbia is divided into sect. Euphorbia, sect. Monadenium (Pax) Bruyns, sect. Goniostema H. Baill. ex Boiss. and sect. Tirucalli Boiss. To re–establish the monophyly of Euphorbia, the genera Endadenium L. C. Leach, Monadenium Pax and Synadenium Boiss. are reduced to synonymy under Euphorbia subg. Euphorbia sect. Monadenium and the species are all transferred to Euphorbia. Consequently the subtribe Euphorbiinae now consists of the single, very large, very widely distributed and very diverse genus Euphorbia. Three of the subgenera (Chamaesyce, Esula, Euphorbia) are nearly cosmopolitan, showing the great age and wide extent of the radiation that has occurred within Euphorbia. The remaining subg. Rhizanthium is mainly African.

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Section: Clade a -mentioning

confidence: 52%

A new subgeneric classification for Euphorbia (Euphorbiaceae) in southern Africa based on ITS and psbA-trnH sequence data

Bruyns

Mapaya

Hedderson

2006

TAXON

135

148

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“…They cited 625 species present in southern Cape Province, and 235 in Caledon District alone. The term Caledon Centre (Croizat 1965) has been taken up by most authors for this region, one of the most dramatic centres of diversity in the world.…”

Section: Ericoideaementioning

confidence: 99%

Ericaceae in Malesia: vicariance biogeography, terrane tectonics and ecology

Heads¹

2003

Telopea

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Heads, Michael (Science Faculty, University of Goroka, PO Box 1078, Goroka, Papua New Guinea. Current address: Biology Department, University of the South Pacific, P.O. Box 1168 2003. Ericaceae in Malesia: vicariance biogeography, terrane tectonics and ecology. Telopea 10(1): 311-449. The Ericaceae are cosmopolitan but the main clades have well-marked centres of diversity and endemism in different parts of the world. Erica and its relatives, the heaths, are mainly in South Africa, while their sister group, Rhododendron and relatives, has centres of diversity in N Burma/SW China and New Guinea, giving an Indian Ocean affinity. The Vaccinioideae are largely Pacific-based, and epacrids are mainly in Australasia. The different centres, and trans-Indian, trans-Pacific and trans-Atlantic Ocean disjunctions all indicate origin by vicariance. The different main massings are reflected in the different distributions of the subfamilies within Malesia. With respect to plant architecture, in Rhododendron inflorescence bracts and leaves are very different. Erica and relatives with the 'ericoid' habit have similar leaves and bracts, and the individual plants may be homologous with inflorescences of Rhododendron. Furthermore, in the ericoids the 'inflorescence-plant' has also been largely sterilised, leaving shoots with mainly just bracts, and flowers restricted to distal parts of the shoot. The epacrids are also 'inflorescence-plants' with foliage comprised of 'bracts', but their sister group, the Vaccinioideae, have dimorphic foliage (leaves and bracts). In Malesian Ericaceae, the four large genera and the family as a whole have most species in the 1500-2000 m altitudinal belt, lower than is often thought and within the range of sweet potato cultivation. The same belt is also most diverse for ferns, birds-of-paradise and bowerbirds. Distribution maps of Malesian Ericaceae are presented, with related species indicated. Concentric patterns of distribution are frequent and could be attributable to evolution around shrinking seas. In New Guinea the main axial range is a composite structure, with the southern part formed by the old Australian craton and the northern and eastern parts formed from 32 tectonostratigraphic terranes or microplates. These formed independently and then docked with each other and the craton. The tectonic boundary between the craton and the accreted terranes is also an important biogeographic boundary. Many taxa have distributions linking different accreted terranes but are not on the craton. Movement and integration of island arcs and more substantial terranes has led to complex patterns of disjunction throughout Malesia, but there is an underlying parallel-arc structure, seen clearly in New Guinea. The tectonic provinces in Borneo are also reflected in the two main biogeographic tracks: Kuching--Kinabalu and Kutei Mts./Mt. Kemul-Kinabalu, the Lupar River boundary and the Meratus Mts. centre. The islands of the Riouw Pocket (Corner 1978a) are notably surrounded by many groups which are absent th...

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“…and E. nicaeensis All. (Croizat, 1972;Benedí et al, 1997). The two species are quite similar in inflorescence architecture, and they produce three-seeded capsules.…”

mentioning

confidence: 99%

Explosive seed dispersal in two perennial Mediterranean Euphorbia species (Euphorbiaceae)

Narbona

Arista

Ortiz

2005

American J of Botany

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The distance of explosive dispersal, its pattern in time, and the relative importance of autochory have been studied in two diplochorous species: Euphorbia boetica and E. nicaeensis. The seeds of E. boetica released by explosive dispersal reached a median distance of 156 cm and a maximum of almost 8 m, while the distances reached by the seeds of E. nicaeensis were lower: a median of 132 cm and a maximum of 5 m. The differences in explosive dispersal distance between species seem to depend on both seed mass and caruncle retention. The seeds of both species present a caruncle, but in E. boetica this is tiny, and in most cases is shed during the explosion of the capsules. The distances reached by the seeds of these species, dispersed just by capsule explosion, were similar to or greater than the distances to which ants disperse seeds in the Mediterranean sclerophyllous vegetation. Diplochorous plants may maximize either the distance of primary dispersal or that of secondary dispersal. Given that the seeds of E. boetica, that lose their caruncles, are not gathered by myrmecochorous ants, the results suggest that E. boetica maximizes its primary dispersal distance, whereas E. nicaeensis favors its secondary dispersal.

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An Introduction to the Subgeneric Classification of « Euphorbia » L., With Stress on the South African and Malagasy Species. I.

Cited by 29 publications

References 0 publications

A new subgeneric classification for Euphorbia (Euphorbiaceae) in southern Africa based on ITS and psbA-trnH sequence data

A new subgeneric classification for Euphorbia (Euphorbiaceae) in southern Africa based on ITS and psbA-trnH sequence data

Ericaceae in Malesia: vicariance biogeography, terrane tectonics and ecology

Explosive seed dispersal in two perennial Mediterranean Euphorbia species (Euphorbiaceae)

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