Allen James Coombes

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• MPhil
• Curator of Scientific Collections at Meritorious Autonomous University of Puebla

Within the genus Quercus there are species with a shrubby habit that have been little studied worldwide. In Mexico, several shrub species within section Quercus are taxonomically highly problematic. These include eight named taxa that share traits such as abaxially tomentose leaves and growth of stems from one or multiple rhizomes, and there is evi...

The article shows that Quercus x hispanica Lam. is the correct name for hybrids between Quercus cerris and Q. suber.

A new species of oak gall wasp, Andricus coombesi Pujade-Villar & Pérez-Torres n. sp. from Mexico, known only from its asexual generation that induces galls on acorns of Quercus grahamii Benth., (section Lobatae) is described. Its presence causes the complete disappearance of the acorn. Diagnosis, distribution and biological data of the new species...

This contribution is part of a series devoted to the phylogeny and taxonomy of powdery mildews, with an emphasis on North American taxa. An overview of Cystotheca species is given, including references to ex-type sequences or, if unavailable, proposals for representative reference sequences for phylogenetic-taxonomic purposes. The new species C. me...

Publication of Quercus x sternbergii

Botanical gardens have extensive spatial databases of their plant specimens; however, the fungi occurring in them are generally unstudied. Botanical gardens, with their great plant diversity, undoubtedly harbor a wide range of symbiotic fungi, including those that are plant-pathogenic. One such group of fungi is powdery mildews (Erysiphaceae). The...

Publication details for the oaks Quercus ×kabylica and Q. ×numidica, described from Algeria, are determined, and lectotypes for both names, as well as for Quercus afares f. spinosa and Q. ×numidica var. brevisquama, are designated. Quercus ×kabylica and Q. ×numidica are regarded as representing the same taxon, for which the correct name is Q. ×numi...

The Red List of Oaks 2020 provides and analyzes IUCN Red List assessments for the estimated 430 species in the genus Quercus—the most complete and comprehensive global analysis of extinction risk for oaks. The only previous global assessment of oaks was published in 2007 and included just 175 species (~40% of the genus; Oldfield and Eastwood, 2007)...

Por tal motivo, este manual pretende, además de dar una introducción y justificación de la importancia de cultivar encinos (Capítulos I y II), dar a conocer de manera accesible las principales técnicas de propagación de los mismos (Quercus), abordando temas como la colecta y almacenamiento de bellotas (Capítulo III), la germinación de los encinos,...

The nomenclature of some species of Quercus described by Lamarck from the Iberian Peninsula is reviewed. Five names are lectotypified and two epitype are designated.

The nomenclature of Quercus splendens, Q. peduncularis, Q. sororia, Q. lancifolia, Q. leiophylla, Q. toxicodendrifolia, Q. gentryi and Q. confertifolia is reviewed by a study of the type specimens, original descriptions and herbarium material. Quercus splendens is regarded as a synonym of Q. peduncularis; Q. sororia and Q. toxicodendrifolia are rec...

Antecedentes y Objetivos: Entre las plantas comúnmente conocidas como malezas se incluyen las ruderales, que prosperan en asentamientos humanos y lugares con perturbación natural o antropogénica. Pocos estudios en México se han enfocado en tales plantas; no obstante, constituyen un componente importante de la flora del país, muchas de ellas son end...

In this work were examined a group of names in the genus Quercus L., which has been used of spot or generalized form in the Iberian Peninsula and the NW of Africa over the last two centuries. The review of these names has shown the necessity of nomenclatural changes in some taxa inhabiting the territory as Q. ×avellaniformis Colmeiro Boutelou, to d...

Analyses of nrDNA and cpDNA (petN-psbM, trnSG, trnDT, trnLF) from J. flaccida, J. poblana, J. p. var. decurrens, and putative hybrids revealed some populations of pure J. flaccida, and a few areas of pure trees of J. poblana. However, most J. poblana or putative hybrids in the eastern part the range were found to be introgressed by chloroplast capt...

A revision of type material of Quercus candicans at the Herbarium of the Real Jardín Botánico de Madrid (MA), as well as the original description revealed misplacement in the genus Quercus (Fagaceae). The type of Q. candicans clearly corresponds to Roldana lineolata (Asteraceae). A detailed study of types and protologues of the synonyms previously...

The Oaks of the Americas Conservation Network (OACN) is an international consortium of oak experts aimed at meeting aimed at filling the gaps in oak research and conservation in North and Central America. As part of their larger effort to connect science to conservation and catalyze collaboration between important oak experts, OACN held a Workshop...

Seven media amended with 30% to 75% (by volume) of spent mushroom compost (SMC) were trialed on two oak tree species to evaluate the possibility of using SMC for oak tree container seedling production by comparing the physical and chemical properties of media and assessing the plant growth of oak seedlings. The high electrical conductivity and pH o...

Leaf epidermal features are useful for elucidating the taxonomy and systematics of oak species. Quercus Group Ilex has a wide distribution mainly in subtropical areas of Eurasia with rich fossil records since the Oligocene, but no comprehensive study has ever been conducted on its diversity of leaf epidermal features. We compared the leaf epidermal...

Quercus lineata is native to Malaysia and Indonesia. During our studies on herbarium collections and field collections, two new distribution records of Q. lineata were found in Hainan island, South China and Central Vietnam. All the key diagnostic features of the specimens from China and Vietnam were consistent with the specimens collected from Mal...

An illustrated catalogue of medicinal samples held at the Herbarium and Botanic Garden of the Benemerita Universidad Autonoma de Puebla, Puebla, Mexico and received from the German pharmaceutical company Merck in the first half of the 20th century

Continued research and fieldwork has documented 48 oak species in the state of Puebla, Mexico. We present here a brief summary of the presence and distribution of oaks of sections Lobatae and Quercus in Puebla, which show interesting patterns and enable us to better understand their cultivation requirements.

Leaf architecture and epidermis features are useful to reveal the taxonomic identities of species in Quercus s.l.. For many years different opinions have existed on the taxonomic status of Quercus tungmaiensis, either as a synonym of Q. lanata or as an independent species. In this study, we compared the leaf epidermal features, leaf architecture an...

Leaf epidermal features are important taxonomic features in Quercus. We studied leaf epidermal features of 91 species and one forma of Quercus subgenus Cyclobalanopsis using light and scanning electron microscopy. Trichome terminology in oaks was assessed and clarified, aiming to score the epidermal features accurately for genus-wide comparison. Ni...

Aeschynanthus longicaulis plants are understory plants in the forest, adapting to low light conditions in their native habitats. To observe the effects of the high irradiance on growth and physiology, plants were grown under two different light levels, PPFD 650 μmol·m(-2) ·s(-1) and 150 μmol·m(-2) ·s(-1) for 6 months. Plants under high irradiance h...

Leaf epidermal features offer excellent diagnostic characteristics for genera of Fagaceae. The survey of leaf epidermal and acorn features of Quercus patkoiensis A. Camus, Quercus semiserratoides (Y.C. Hsu & H.W. Jen) C.C. Huang & Y.T. Chang, Q. semiserrata Roxb. and Lithocarpus litseifolius (Hance) Chun revealed that the type material of Q. patkoi...

Based on a survey of literature and specimens, the lectotype of Quercus brandisiana Kurz is designated here. Information on its distribution, taxonomy and leaf epidermal features is given. Features that distinguish Q. brandisiana from closely related species are given and a key to their identification is provided.

The lectotypes of Quercus acuta Thunb. and Q. glauca Thunb. are designated. The fine details of leaf epidermal features of the two species are elaborated for future comparison with other closely related species.

The evergreen Mexican oak, Quercus crassifolia Bonpl. is illustrated; its distribution is given and related species are discussed. Its survival in gardens in England is noted.

A Chinese evergreen oak, Quercus guyavifolia A. Lév., from Yunnan, and Sichuan, is illustrated and compared with related species. Its cultivation is considered.

The name Quercus arbutifolia Hickel & A. Camus is lectotypifed. In addition, leaf epidermal features of Q. obovatifolia C. C. Huang, Q. arbutifolia and four other closely related species, Q. daimingshanensis (S. K. Lee) C. C. Huang, Q. merrillii Seemen, Q. litseoides Dunn and Q. tiaoloshanica Chun & W. C. Ko, were studied and compared using herbari...

The name Quercus cambodiensis Hickel & A. Camus (Fagaceae) is lectotypified herein. Based on morphological comparison and wild population observation, seven names within Quercus subg. Cyclobalanopsis (Oerst.) C. K. Schneid. (Fagaceae) are synonymized: Q. patelliformis Chun to Q. asymetrica Hickel & A. Camus; Cyclobalanopsis yingjiangensis Y. C. Hsu...

Cytological studies were carried out for the first time on five populations of Trigonobalanus doichangensis in China and Thailand. In all populations, the pattern of interphase nuclei was of the simple chromocentre type, the mitotic prophases were of the proximal interstitial type and chromosome numbers were 2n = 2x = 14. Two B chromosomes were com...

Trigonobalanus doichangensis is a national rare and endangered plant of China. It is restricted to 4 sites in southwest Yunnan, China and 1 site in Chiang-Rai, northern Thailand. Investigations revealed that 4 community types are currently extant in Yunnan: isolated individuals, sprouting woods, mono-dominant forest and co-dominant forest. The habi...

Three new combinations in the genus Cyclobalanopsis are proposed based on examination of type materials and other specimens. Quercus fleuryi Hickel & A. Camus and Q. macrocalyx Hickel & A. Camus var. tomentosa Metcalf are treated as synonyms of C. macrocalyx and C. kouangsiensis (A. Camus) Y.C. Hsu & H.W. Jen, respectively. The taxonomic treatment...

Trigonobalanus doichangensis is a national rare and endangered plant of China. It is restricted to 4 sites in southwest Yunnan, China and 1 site in Chiang-Rai, northern Thailand. Investigations revealed that 4 community types are currently extant in Yunnan: isolated individuals, sprouting woods, mono-dominant forest and co-dominant forest. The habi...

Morphological and chromosomal evidence for the identification of cultivars of Quercus ×hispanica, the Lucombe oak has often been inconclusive. The use of DNA fingerprinting techniques has proved helpful for such identifications. Using inter-simple sequence repeat (ISSRs) primers, 66 Q. ×hispanica (and related) samples were analysed and compared for...

Problems in both botanical and horticultural nomenclature can arise when a species is named from a garden plant selected for characters which distinguish it from naturally occurring forms of the species. As long as it is accepted that the various forms involved do not need to be distinguished botanically, then these problems can be resolved by rega...

Problems in both botanical and horticultural nomenclature can arise when a species is named from a garden plant selected for characters which distinguish it from naturally occurring forms of the species. As long as it is accepted that the various forms involved do not need to be distinguished botanically, then these problems can be resolved by rega...

Excised barley roots were allowed to absorb copper for four hours. Three different chemical forms of copper were applied to root samples at identical initial concentrations. The roots were then desorbed in 0.05 mm CaCl2 for 24 hours. Replicated root samples were removed from the desorbing solution at regular time intervals and analysed for copper c...

Uptake of various chemical forms of copper has been studied, using excised Barleyroots. Results show that accumulation of copper in this tissue may be markedly affected by the chemical form of the applied copper. In particular, the overall charge carried by the applied copper complex is suggested to be a primary determining factor. Uptake of two di...

Levels of IAA-oxidase activity in root preparations of copper-treated Barley plants and seedlings were found to be closely related to root copper content. At root copper contents below 1000 ppm, IAA-oxidase activity was promoted, but marked inhibition of enzyme activity occurred at root copper levels in excess of this. The results are discussed in...

Toxic effects of both zinc and copper have been demonstrated in germmalings of Marchantia polymorpha L. and in germinating spores of Funaria hygrometrica Hedw. Copper was found to be more toxic than zinc in both species. Copper levels above 8 ppm resulted in cessation of protonemal growth and inhibition of spore germination in Funaria, and, much re...