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Tom Eke - One of the best experts on this subject based on the ideXlab platform.
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Euphorbia sap keratouveitis.
British Journal of Ophthalmology, 1997Co-Authors: Tom EkeAbstract:Editor,—I congratulate Scott and Karp for their excellent paper on Euphorbia sap keratopathy,1 but would like to emphasise that the sap of certain plants of this genus can cause blindness. Clinicians should be aware of the sight threatening uveitis caused by some Euphorbias. Duke-Elder has reviewed the older literature, citing reports of severe keratouveitis caused by the sap of the European perennial herb Euphorbia esula (previously Tithymalus esula ) and a Cuban species recorded as E antiquorum .2 Uveitis with hypopyon has been described …
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Euphorbia sap keratouveitis.
British Journal of Ophthalmology, 1997Co-Authors: Tom EkeAbstract:Editor,—I congratulate Scott and Karp for their excellent paper on Euphorbia sap keratopathy,1 but would like to emphasise that the sap of certain plants of this genus can cause blindness. Clinicians should be aware of the sight threatening uveitis caused by some Euphorbias. Duke-Elder has reviewed the older literature, citing reports of severe keratouveitis caused by the sap of the European perennial herb Euphorbia esula (previously Tithymalus esula ) and a Cuban species recorded as E antiquorum .2 Uveitis with hypopyon has been described …
Peter V. Bruyns - One of the best experts on this subject based on the ideXlab platform.
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A review of the Euphorbia schinzii -complex (Euphorbiaceae) in southern Africa
Phytotaxa, 2020Co-Authors: Peter V. Bruyns, Cornelia Klak, Pavel HanáčekAbstract:The species closely related to Euphorbia schinzii in subg. Euphorbia are reviewed for southern Africa. Two new species, E. pisima and E. steelpoortensis are described that are closely related to E. lydenburgensis. Euphorbia complexa is reduced to synonymy under E. schinzii. One new subspecies, E. schinzii subsp. schinzioides, is described for E. schinzii, while E. limpopoana is reduced once again to subspecific level, this time under E. schinzii as E. schinzii subsp. bechuanica. Euphorbia schinzii then has three subspecies. The concept of E. clivicola is extended to include collections from a much wider area than before. A new subspecies, E. clivicola subsp. calcritica, is described for E. clivicola. Euphorbia subsalsa subsp. fluvialis is more closely related to E. otjipembana than to E. subsalsa and consequently is changed to E. otjipembana subsp. fluvialis.
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A further new species of Euphorbia (Euphorbiaceae) from Moçambique
Phytotaxa, 2020Co-Authors: Peter V. BruynsAbstract:A small shrubby species of Euphorbia belonging to subg. Euphorbia is described from the central part of Moçambique. It is closely related to E. contorta.
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New Taxa in Euphorbia (Euphorbiaceae) in Southern Africa
Haseltonia, 2018Co-Authors: Peter V. BruynsAbstract:In preparation for a monograph of Euphorbia in southern Africa, twelve new taxa are described.In Euphorbia subsect. Medusea (Haw.) Pax & K. Hoffm. one new species, E. willowmorensis Bruyns and three new subspecies, E. arida subsp. camdebooensis Bruyns, E. friedrichiae subsp. pofadderensis Bruyns and E. multiceps subsp. tanquana Bruyns are described; two new subspecies, E. ferox subsp. calitzdorpensis Bruyns and E. pseudoglobosa subsp. vlokii Bruyns are described in Euphorbia ser. MelEuphorbia (A.Berger) Bruyns; one new subspecies, Euphorbia patula subsp. brucebayeri Bruyns is described in Euphorbia subsect. Dactylanthes (Haw.) Pax & K.Hoffm.In Euphorbia sect. Articulofruticosae Bruyns one new subspecies, E. ephedroides subsp. gamsbergensis Bruyns is described.In Euphorbia sect. Esula (Pers.) Dumort. one new species, E. corneliae Bruyns, is described from southern Namibia.In Euphorbia sect. Euphorbia there are one new species, E. otavibergensis Bruyns; one new subspecies E. subsalsa subsp. otzenii Bruyns; and one new variety, E. lydenburgensis var. minor Bruyns.In addition, in subsect. Dactylanthes the concept of Euphorbia patula Mill. is substantially re-configured and four subspecies are recognized, with E. anacantha Aiton and E. wilmaniae Marloth included as two of these subspecies.
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a new subgeneric classification for Euphorbia Euphorbiaceae in southern africa based on its and psba trnh sequence data
Taxon, 2006Co-Authors: Peter V. Bruyns, Ruvimbo J Mapaya, Terrence J HeddersonAbstract: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.
Ricarda Riina - One of the best experts on this subject based on the ideXlab platform.
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evolutionary bursts in Euphorbia Euphorbiaceae are linked with photosynthetic pathway
Evolution, 2014Co-Authors: James W Horn, Zhenxiang Xi, Ricarda Riina, Jess A Peirson, Brian L Dorsey, Paul E Berry, Charles C Davis, Ya Yang, Kenneth J WurdackAbstract:: The mid-Cenozoic decline of atmospheric CO2 levels that promoted global climate change was critical to shaping contemporary arid ecosystems. Within angiosperms, two CO2 -concentrating mechanisms (CCMs)-crassulacean acid metabolism (CAM) and C4 -evolved from the C3 photosynthetic pathway, enabling more efficient whole-plant function in such environments. Many angiosperm clades with CCMs are thought to have diversified rapidly due to Miocene aridification, but links between this climate change, CCM evolution, and increased net diversification rates (r) remain to be further understood. Euphorbia (∼2000 species) includes a diversity of CAM-using stem succulents, plus a single species-rich C4 subclade. We used ancestral state reconstructions with a dated molecular phylogeny to reveal that CCMs independently evolved 17-22 times in Euphorbia, principally from the Miocene onwards. Analyses assessing among-lineage variation in r identified eight Euphorbia subclades with significantly increased r, six of which have a close temporal relationship with a lineage-corresponding CCM origin. Our trait-dependent diversification analysis indicated that r of Euphorbia CCM lineages is approximately threefold greater than C3 lineages. Overall, these results suggest that CCM evolution in Euphorbia was likely an adaptive strategy that enabled the occupation of increased arid niche space accompanying Miocene expansion of arid ecosystems. These opportunities evidently facilitated recent, replicated bursts of diversification in Euphorbia.
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Synopsis of Euphorbia subgen. Esula sect. Helioscopia (Euphorbiaceae) in Iran with the description of Euphorbia mazandaranica sp. nov.
Nordic Journal of Botany, 2014Co-Authors: Amir Hossein Pahlevani, Ricarda RiinaAbstract:Euphorbia subgen. Esula with about 480 species is one of the most diverse and complex lineages of the giant genus Euphorbia. Species of this subgenus are usually herbaceous and are mainly distributed in temperate areas of the Northern Hemisphere. This paper updates the taxonomy and distribution of Euphorbia (subgen. Esula) sect. Helioscopia in Iran since the publication of ‘Flora Iranica’ in 1964. We provide a key, species descriptions, illustrations (for most species), distribution maps, brief characterization of ecology as well as relevant notes for the 12 species of this section occurring in Iran. As a result of this revision, E. altissima var. altissima is reported as new for the country, and a new species from northern Iran, Euphorbia mazandaranica, is described and illustrated. With the exception of E. helioscopia, a widespread weed in temperate regions worldwide, the remaining species occur in the Alborz, Zagros and northwestern regions of Iran.
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phylogenetics and the evolution of major structural characters in the giant genus Euphorbia l Euphorbiaceae
Molecular Phylogenetics and Evolution, 2012Co-Authors: James W Horn, Ricarda Riina, Paul E Berry, Jeffery J Morawetz, Victor W Steinmann, Kenneth J WurdackAbstract:Abstract Euphorbia is among the largest genera of angiosperms, with about 2000 species that are renowned for their remarkably diverse growth forms. To clarify phylogenetic relationships in the genus, we used maximum likelihood, Bayesian, and parsimony analyses of DNA sequence data from 10 markers representing all three plant genomes, averaging more than 16 kbp for each accession. Taxon sampling included 176 representatives from Euphorbioideae (including 161 of Euphorbia ). Analyses of these data robustly resolve a backbone topology of four major, subgeneric clades— Esula , Rhizanthium , Euphorbia , and Chamaesyce —that are successively sister lineages. Ancestral state reconstructions of six reproductive and growth form characters indicate that the earliest Euphorbia species were likely woody, non-succulent plants with helically arranged leaves and 5-glanded cyathia in terminal inflorescences. The highly modified growth forms and reproductive features in Euphorbia have independent origins within the subgeneric clades. Examples of extreme parallelism in trait evolution include at least 14 origins of xeromorphic growth forms and at least 13 origins of seed caruncles. The evolution of growth form and inflorescence position are significantly correlated, and a pathway of evolutionary transitions is supported that has implications for the evolution of Euphorbia xerophytes of large stature. Such xerophytes total more than 400 species and are dominants of vegetation types throughout much of arid Africa and Madagascar.
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Euphorbia: a global inventory of the spurges
Blumea - Biodiversity Evolution and Biogeography of Plants, 2009Co-Authors: H.-j. Esser, Paul E Berry, Ricarda RiinaAbstract:The Euphorbia project, a global inventory of the giant genus Euphorbia, is introduced. The project began recently under the auspices of the U.S. National Science Foundation’s program in Planetary Biodiversity Inventories (PBI).
Abdul Samad Mumtaz - One of the best experts on this subject based on the ideXlab platform.
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Melampsora pakistanica sp. nov., a new rust fungus on Euphorbia helioscopia (Sun spurge) from Pakistan
Mycological Progress, 2016Co-Authors: Younas Sohail, Merje Toome-heller, Abdul Samad MumtazAbstract:A rust fungus was found on the leaves of Euphorbia helioscopia during a field study in Pakistan. Previously, Melampsora Euphorbiae , M. Euphorbiae - gerardianae and M. helioscopiae have been reported on E. helioscopia , the first two of which are also known from Pakistan. Morphological observations of the newly collected rust samples detected some differences from the previously described Melampsora species on E. helioscopia . The molecular analysis of the ITS and LSU sequences also detected that the rust is different from the previously reported rusts described from E. helioscopia . Based on both morphological comparisons and sequence analysis, the rust is described here as M. pakistanica sp. nov. This species could have potential as a bio-control agent against its host plant— E. helioscopia —which is a weed of wheat fields in Pakistan and elsewhere in the world.
Willem F. De Boer - One of the best experts on this subject based on the ideXlab platform.
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Continued decline in tree Euphorbias (Euphorbia tetragona and E. triangularis) on the Great Fish River Reserve, Eastern Cape, South Africa
African Journal of Ecology, 2010Co-Authors: Peter C. Lent, H. Eshuis, R. Van Krimpen, Willem F. De BoerAbstract:A dramatic decline averaging 43% over a 4-year period has occurred in tree Euphorbia (Euphorbia tetragona and Euphorbia triangularis) populations on the Great Fish River Reserve, South Africa. These changes are evident from data gathered by general vegetation monitoring methods as well as from a focused study of four tree Euphorbia populations. The decline from 2003 to 2007 was more marked for E. triangularis than for E. tetragona and was accompanied by a general absence of seedlings and a reduced presence of younger age classes of both species, decreasing the proportion of younger trees in the populations. The role of megaherbivores, specifically the black rhinoceros, in these changes is well established. However, the impact of baboon activity, leading to damage to tree crowns and upper branches, is also substantial, especially on E. triangularis populations. Damaged crowns were recorded significantly more often for E. triangularis than for E. tetragona, and the damage frequency increased with decreasing tree height. Thus, our work provides the first evidence that these two closely related Euphorbia species may be affected differently by herbivory.
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Will tree Euphorbias (Euphorbia tetragona and Euphorbia triangularis) survive under the impact of black rhinoceros (Bicornis diceros minor) browsing in the Great Fish River Reserve, South Africa?
African Journal of Ecology, 2006Co-Authors: Linda C. Heilmann, Karen De Jong, Peter C. Lent, Willem F. De BoerAbstract:The impact of black rhinoceros (Bicornis diceros minor) on the tree Euphorbias Euphorbia tetragona and Euphorbia triangularis was studied in the Great Fish River Reserve, South Africa. Black rhinoceros pushed over about 5–7% of the trees in a 2-month period. There was a preference of rhinos for smaller trees, however this preference did not guarantee Euphorbia survival in the larger size classes. This means that tree Euphorbias could very well disappear from all areas accessible to rhinos. Rhino feeding choices were correlated with higher plant moisture content, higher nitrogen content, and a higher digestibility.
