The Eriochilus dilatatus (Orchidaceae) complex in Western Australia: subspecies taxonomy is not supported by consistent differences in morphology or distribution

2020 ◽  
Author(s):  
Mark C. Brundrett ◽  
Timothy A. Hammer
Keyword(s):  
Western Australia ◽  
Leaf Morphology ◽  
Habitat Preferences ◽  
Leaf Size ◽  
Distribution Patterns ◽  
Critical Examination ◽  
Herbarium Specimens ◽  
Taxonomic Confusion ◽  
Leaf Size And Shape ◽  
Western Australian

A detailed study of taxonomic features of the Eriochilus dilatatus (Orchidaceae) complex (white bunny orchids) in Western Australia found that there were no consistent differences among most subspecies when herbarium specimens or living plants were compared. These subspecies were originally segregated primarily by differences in leaf size and shape and the number of flowers produced, but a critical examination of herbarium specimens found that these features were highly inconsistent within taxa. These features were also found to be highly variable over time and space within populations of living plants. The distribution patterns, habitat preferences and flowering times of these taxa were found to overlap, even for subspecies brevifolius and orientalis, which occupy the northern and eastern limits of the distribution of this species. Eriochilus dilatatus subsp. magnus and subsp. multiflorus were shown to be synonyms of subsp. dilatatus, whereas subsp. undulatus and subsp. orientalis are synonymised under subsp. brevifolius. As a result of this study, the two recognised subspecies are subsp. dilatatus and subsp. brevifolius, which can be readily separated by plant height, flower numbers and leaf morphology, except for a few intermediate plants where ranges overlap. New keys and descriptions to these taxa are provided. The reasons for previous taxonomic confusion in this group and in many other Western Australian orchids are discussed and research approaches to resolve these issues are suggested.

New species of xeromorphic Banksia (Proteaceae) foliage and Banksia-like pollen from the late Eocene of Western Australia

2020 ◽  
Vol 68 (3) ◽  
pp. 165 ◽  
Author(s):  
Raymond J. Carpenter ◽  
Lynne A. Milne
Keyword(s):  
New Species ◽  
Western Australia ◽  
Leaf Morphology ◽  
Lower Surface ◽  
Late Eocene ◽  
Leaf Type ◽  
Late Neogene ◽  
Evolutionary Pathways ◽  
Climatic Aridity ◽  
Western Australian

Banksia microphylla leaf fossils and Banksieaeidites zanthus pollen are newly described from late Eocene lignite of the Zanthus-11 borehole, drilled east of Norseman in Western Australia. The leaf fossils are the first known in Banksia to show extreme narrowness (<1.5 mm wide) combined with the xeromorphic trait of margins rolled onto the lower surface so that the diffusely placed stomata are exposed to the outside environment only via grooves on each side of a thick, abaxial midrib. Both this Banksia leaf type and another with encrypted stomata evolved before the widespread initiation of severe climatic aridity in the late Neogene, likely in regions of edaphic infertility and periodic water stress. New interpretations of leaf morphology and foliar evolutionary pathways in Banksia are proposed. Banksia microphylla probably belongs to subgenus Spathulatae, where it strongly resembles many species in the large, wholly Western Australian clade that includes most species in section Oncostylis, series Abietinae. Banksieaeidites zanthus is morphologically consistent with Banksia pollen, and its extremely small size also suggests placement in Spathulatae. The new fossils and other evidence from Zanthus-11 indicate the local presence of quite open, sclerophyll vegetation with conifers, which was unlikely to have been frequently burnt.

scholarly journals Vein-to-blade ratio is an allometric indicator of climate-induced changes in grapevine leaf size and shape

2020 ◽  
Author(s):  
Daniel H. Chitwood ◽  
Joey Mullins ◽  
Zoë Migicovsky ◽  
Margaret Frank ◽  
Robert VanBuren ◽  
...  
Keyword(s):  
Leaf Morphology ◽  
Heat Waves ◽  
Leaf Size ◽  
Climate Variables ◽  
Size And Shape ◽  
Growing Seasons ◽  
Blade Area ◽  
Grapevine Leaves ◽  
Leaf Size And Shape ◽  
Induced Changes

ABSTRACTPremiseAs a leaf expands, its shape dynamically changes. Previously, we documented an allometric relationship between vein and blade area in grapevine leaves. Larger leaves have a smaller ratio of primary and secondary vein area relative to blade area compared to smaller leaves. We sought to use allometry as an indicator of leaf size to measure the environmental effects of climate on grapevine leaf morphology.MethodsWe measure the ratio of vein-to-blade area in 8,412 leaves from the same 208 vines across four growing seasons (2013, 2015, 2016, and 2017) using 21 homologous landmarks. Matching leaves by vine and node, we correlate size and shape of grapevine leaves with climate variables.Key resultsVein-to-blade ratio varies strongly between years in ways that blade or vein area do not. Maximum daily temperature and to a lesser degree precipitation are the most strongly correlated climate variables with vein-to-blade ratio, indicating that smaller leaves are associated with heat waves and drought. Leaf count and overall leaf area of shoots and the vineyard population studied also diminish with heat and drought. Grapevine leaf primordia initiate in buds the year prior to when they emerge, and we find that climate during the previous growing season exerts the largest statistical effects over these relationships.ConclusionsOur results demonstrate the profound effects of heat and drought on the vegetative morphology of grapevines and show that vein-to-blade ratio is a strong allometric indicator of the effects of climate on grapevine leaf morphology.

scholarly journals LsAP2 regulates leaf morphology by inhibiting CIN-like TCP transcription factors and repressing LsKAN2 in lettuce

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Chen Luo ◽  
Shenglin Wang ◽  
Kang Ning ◽  
Zijing Chen ◽  
Yixin Wang ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Transcriptional Activation ◽  
Leaf Development ◽  
Leaf Morphology ◽  
Molecular Mechanisms ◽  
Leaf Size ◽  
Leafy Vegetables ◽  
Sequencing Analysis ◽  
Agricultural Yield ◽  
Leaf Size And Shape

AbstractLeaf size and flatness directly affect photosynthesis and are closely related to agricultural yield. The final leaf size and shape are coordinately determined by cell proliferation, differentiation, and expansion during leaf development. Lettuce (Lactuca sativa L.) is one of the most important leafy vegetables worldwide, and lettuce leaves vary in shape and size. However, the molecular mechanisms of leaf development in lettuce are largely unknown. In this study, we showed that the lettuce APETALA2 (LsAP2) gene regulates leaf morphology. LsAP2 encodes a transcriptional repressor that contains the conserved EAR motif, which mediates interactions with the TOPLESS/TOPLESS-RELATED (TPL/TPR) corepressors. Overexpression of LsAP2 led to small and crinkly leaves, and many bulges were seen on the surface of the leaf blade. LsAP2 physically interacted with the CINCINNATA (CIN)-like TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors and inhibited their transcriptional activation activity. RNA sequencing analysis showed that LsAP2 affected the expression of auxin- and polarity-related genes. In addition, LsAP2 directly repressed the abaxial identity gene KANADI2 (LsKAN2). Together, these results indicate that LsAP2 regulates leaf morphology by inhibiting CIN-like TCP transcription factors and repressing LsKAN2, and our work provides insights into the regulatory mechanisms of leaf development in lettuce.

scholarly journals Spatiotemporal variation in leaf size and shape in response to climate

2019 ◽  
Vol 13 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Yaoqi Li ◽  
Dongting Zou ◽  
Nawal Shrestha ◽  
Xiaoting Xu ◽  
Qinggang Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Intraspecific Variation ◽  
Leaf Shape ◽  
Leaf Size ◽  
Leaf Length ◽  
Herbarium Specimens ◽  
Size And Shape ◽  
Length Width ◽  
Leaf Size And Shape ◽  
Over Time

Abstract Aims Morphological variation of leaves is a key indicator of plant response to climatic change. Leaf size and shape are associated with carbon, water and energy exchange of plants with their environment. However, whether and how leaf size and shape responded to climate change over the past decades remains poorly studied. Moreover, many studies have only explored inter- but not intraspecific variation in leaf size and shape across space and time. Methods We collected >6000 herbarium specimens spanning 98 years (1910–2008) in China for seven representative dicot species and measured their leaf length and width. We explored geographical patterns and temporal trends in leaf size (i.e. leaf length, leaf width and length × width product) and shape (i.e. length/width ratio), and investigated the effects of changes in precipitation and temperature over time and space on the variation in leaf size and shape. Important Findings After accounting for the effects of sampling time, leaf size decreased with latitude for all species combined, but the relationship varied among species. Leaf size and shape were positively correlated with temperature and precipitation across space. After accounting for the effects of sampling locations, leaf size of all species combined increased with time. Leaf size changes over time were mostly positively correlated with precipitation, whereas leaf shape changes were mostly correlated with temperature. Overall, our results indicate significant spatial and temporal intraspecific variation in leaf size and shape in response to climate. Our study also demonstrates that herbarium specimens collected over a considerable period of time provide a good resource to study the impacts of climate change on plant morphological traits.

scholarly journals Response of Leaf Traits of Eastern Qinghai-Tibetan Broad-Leaved Woody Plants to Climatic Factors

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaomei Kang ◽  
Yanan Li ◽  
Jieyang Zhou ◽  
Shiting Zhang ◽  
Chenxi Li ◽  
...  
Keyword(s):  
Water Use ◽  
Leaf Morphology ◽  
Leaf Size ◽  
Leaf Traits ◽  
Climate Factors ◽  
Leaf Trait ◽  
Size And Shape ◽  
Stomata Size ◽  
Organ Level ◽  
Leaf Size And Shape

Plant ecologists have long been interested in quantifying how leaf traits vary with climate factors, but there is a paucity of knowledge on these relationships given a large number of the relevant leaf traits and climate factors to be considered. We examined the responses of 11 leaf traits (including leaf morphology, stomatal structure and chemical properties) to eight common climate factors for 340 eastern Qinghai-Tibetan woody species. We showed temperature as the strongest predictor of leaf size and shape, stomatal size and form, and leaf nitrogen and phosphorus concentrations, implying the important role of local heat quantity in determining the variation in the cell- or organ-level leaf morphology and leaf biochemical properties. The effects of moisture-related climate factors (including precipitation and humidity) on leaf growth were mainly through variability in leaf traits (e.g., specific leaf area and stomatal density) related to plant water-use physiological processes. In contrast, sunshine hours affected mainly cell- and organ-level leaf size and shape, with plants developing small/narrow leaves and stomata to decrease leaf damage and water loss under prolonged solar radiation. Moreover, two sets of significant leaf trait-climate relationships, i.e., the leaf/stomata size traits co-varying with temperature, and the water use-related leaf traits co-varying with precipitation, were obtained when analyzing multi-trait relationships, suggesting these traits as good indicators of climate gradients. Our findings contributed evidence to enhance understanding of the regional patterns in leaf trait variation and its environmental determinants.

Rare sporophyte found in Europe for Herbertus sendtneri with a range expansion to Africa and Malesia

Phytotaxa ◽  
2017 ◽  
Vol 324 (1) ◽  
pp. 42
Author(s):  
XIAOLAN HE ◽  
YU SUN
Keyword(s):  
Northern Hemisphere ◽  
Solomon Islands ◽  
Leaf Size ◽  
Herbarium Specimens ◽  
Leaf Base ◽  
New Synonyms ◽  
Morphological Studies ◽  
Phylogenetic Studies ◽  
Molecular Phylogenetic ◽  
Leaf Size And Shape

The sporophytes of the genus Herbertus are rare or completely absent in some areas. The first discovery of the sporophyte of Herbertus in Europe, on H. sendtneri from a herbarium specimen collected in Austria in 1851, is reported here. We report that finely papillose spores characterize Herbertus species which have originated in the Northern Hemisphere, whereas the spores of the species which have originated in the Southern Hemisphere are tuberculate or shortly spinulose. Based on morphological studies of over 600 herbarium specimens of Herbertus, supported by previously published molecular phylogenetic studies, H. armitanus and H. circinatus are new synonyms of H. sendtneri. It is distinct from other Northern Hemisphere species by its coarsely toothed leaf base, despite large variation in leaf size and shape, and leaf apex cilia. The range of H. sendtneri is now extended to east Africa (Tanzania) and Malesia (Papua New Guinea and the Solomon Islands).

Herbivory and the evolution of leaf size and shape

1991 ◽  
Vol 333 (1267) ◽  
pp. 265-272 ◽  
Keyword(s):  
Plant Species ◽  
Leaf Morphology ◽  
Leaf Size ◽  
Size And Shape ◽  
Interspecific Differences ◽  
Feeding Efficiency ◽  
Physical Barriers ◽  
Selective Forces ◽  
Biomechanical Constraints ◽  
Leaf Size And Shape

Why do leaves have such varied sizes and shapes? Part of the answer lies in physiological and biomechanical demands imposed by different habitats; selective forces that are now reasonably well understood. In contrast, the im pact of herbivores on the evolution of leaf size and shape has rarely been investigated and is poorly understood. There are at least six ways in which herbivores, particularly vertebrates and insects, may have influenced the evolution of leaf size and shape, favouring leaf morphologies that differ from those dictated by physiological and biomechanical constraints acting on plants. They are mimicry, not only of leaves of other plant species but also grazed leaves and inanim ate objects; crypsis; physical barriers to being eaten; interspecific differences in leaf morphology to reduce recognition by herbivores; very small or highly divided and dissected leaves that reduce feeding efficiency; and different adult and juvenile foliages. There is an urgent need for studies specifically designed to investigate the im pact of herbivores on leaf size and shape.

scholarly journals Distribution of the Pearl Oyster Pinctada maxima off Eighty Mile Beach, Western Australia

2021 ◽  
Vol 8 ◽  
Author(s):  
Steve Whalan ◽  
Marji Puotinen ◽  
Mary Wakeford ◽  
Iain Parnum ◽  
Karen Miller
Keyword(s):  
Western Australia ◽  
Benthic Communities ◽  
Distribution Patterns ◽  
Pearl Oyster ◽  
Video Data ◽  
Contour Lines ◽  
Acoustic Methods ◽  
The Status ◽  
Pinctada Maxima ◽  
Western Australian

The silver-lipped pearl oyster, Pinctada maxima, is the primary species used for the culture of pearls in the Indo-Pacific region. The Western Australian fishery relies on wild-caught animals, and as such, knowledge of the status and distribution of P. maxima underpins sustainable management of the fishery. Eighty Mile Beach, in tropical Western Australia, is the key harvest area for P. maxima, with oysters collected by divers to depths of ∼35 m, although there are anecdotal accounts of oysters beyond diving depths. Image-based, and acoustic methods were used to elucidate distribution patterns of P. maxima off Eighty Mile Beach, including data from 862 km2 of multibeam survey and 119 towed video transects spanning an area from the 20 to 100 m contour lines. We quantified habitat characters including depth, substrate, and benthic community composition associated with pearl oyster distribution. Multibeam sonar data was also coupled with towed video data to produce predictive statistical models of P. maxima habitat. We found P. maxima to depths of 76 m, although more than 90% of individuals occurred shallower than 40 m and less than 2% were found deeper than 50 m. Oysters occupied flat, sandy habitats with neighbouring benthic communities of filter feeders (>98% of observations). These results show P. maxima predominantly occurs in depths <40 m, with no evidence that extensive populations extend into deep water in the region.

Phenotypic variation of Chinese aspens and their relationships to similar taxa in Europe and North America

1993 ◽  
Vol 71 (6) ◽  
pp. 799-815 ◽  
Author(s):  
Burton V. Barnes ◽  
Fuqing Han
Keyword(s):  
Leaf Morphology ◽  
Leaf Shape ◽  
Leaf Size ◽  
Central China ◽  
Southwestern China ◽  
Herbarium Specimens ◽  
Clinal Variation ◽  
Population Differences ◽  
North Central ◽  
Polymorphic Species

Morphological variation of leaves and pubescence of buds and shoots from Chinese aspen taxa (sect. Populus of Populus) were studied and compared with those of North American aspens. Data were analyzed for 648 clones from 19 Provinces of Chinese aspen taxa identified on herbarium specimens as P. bonatii Gomb., P. davidiana Dode, P. rotundifolia Griff. var. bonatii Gomb., P. rotundifolia Griff. var. duclouxiana (Dode) Gomb., and P. tremula L. In addition, data from field collections of intact shoots of 137 clones of P. davidiana (Heilongjiang, Jilin, and Shaanxi Provinces) and from 821 clones of P. tremula from Europe were also analyzed. Leaf morphology of herbarium specimens identified as P. davidiana, the most widely distributed Chinese taxon, varied markedly among populations, especially between northern and southwestern China. Clones of P. davidiana from northern and northwestern China were markedly different from those of the P. rotundifolia complex of southwestern China. However, clones identified as P. davidiana from southwestern China were similar to those of P. rotundifolia in leaf shape, number of teeth, and pubescence; they differed only in leaf size. Striking within- and among-population differences were found for field collections of P. davidiana in northeast China. Buds and seasonally determinate shoots of P. davidiana were glabrous in northeast and north-central China; pubescence increased markedly to the southwest. Buds and shoots of clones of the P. rotundifolia complex and P. tremula were predominantly pubescent. The Eurasian aspen taxa are enormously polymorphic in leaf morphology and pubescence; clinal variation along geographic gradients in China, Japan, and Europe are pronounced. Based on studies to date, we would tend to recognize P. davidiana and P. rotundifolia as races of P. tremula. It may be that in all of Eurasia there is but a single, highly polymorphic species, viz. P. tremula. Key words: aspens, China, Eurasia, Populus, morphology, systematics.

Intersexual differences in leaf size and shape in dioecious Adriana tomentosa [Euphorbiaceae]

2020 ◽  
Author(s):  
Mariola Rabska ◽  
Nigel W M Warwick ◽  
Grzegorz Iszkuło ◽  
Caroline L Gross
Keyword(s):  
Aspect Ratio ◽  
Leaf Area ◽  
Leaf Morphology ◽  
C:N Ratio ◽  
Leaf Age ◽  
Leaf Size ◽  
Dry Matter Content ◽  
Size And Shape ◽  
Eastern Australia ◽  
Leaf Size And Shape

Abstract Aims Leaf size and shape as objects of natural selection can play adaptive roles, and can change with the age of leaves. They can differ between sexes in dioecious species, and in most cases, females have larger leaves. Previous studies showed that sexes of Adriana tomentosa differed in their leaf lobing. In this study we investigated whether there were other differences between sexes in leaf size, shape and ecophysiology, and if those differences were connected with adaptations and reproductive roles in the sexes of A. tomentosa. Methods Physical and chemical features of young and old leaves originating from female and male A. tomentosa plants growing in two disjunct populations in eastern Australia were measured. We determined leaf area, perimeter length, serration, circularity, aspect ratio, roundness and the ecophysiological factors: SLA, dry matter content, leaf moisture, RWC, δ 13C, δ 15N isotope ratios, carbon and nitrogen contents and C:N ratio. Leaf lobing, the degree of lamina damage and the content of photosynthetic pigments were also determined. Important Findings In both populations studied, the sex of plants significantly influenced almost all parameters connected with leaf morphology such as area, perimeter length, circularity, aspect ratio and roundness. Contrary to expectations, males from both populations had a greater leaf area that was independent of leaf age. Male leaves were more lobed with a longer perimeter, but they were less elongated and less serrated. Only small differences between female and male leaves were observed for the ecophysiological factors. The degree of leaf damage differed between sexes but also with population. Differences between sexes in leaf area and shape were not compensated by measured ecophysiological factors. However, leaf area may be compensated by other ecophysiological mechanisms related to leaf morphology, because females had greater leaf serration in comparison to males despite the smaller leaf area.

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