Comparison of dwarf bamboos (Indocalamus sp.) leaf parameters to determine relationship between spatial density of plants and total leaf area per plant

The relationship between spatial density and size of plants is an important topic in plant ecology. The self‐thinning rule suggests a ?3/2 power between average biomass and density or a ?1/2 power between stand yield and density. However, the self‐thinning rule based on total leaf area per plant and density of plants has been neglected presumably because of the lack of a method that can accurately estimate the total leaf area per plant. We aimed to find the relationship between spatial density of plants and total leaf area per plant. We also attempted to provide a novel model for accurately describing the leaf shape of bamboos. We proposed a simplified Gielis equation with only two parameters to describe the leaf shape of bamboos one model parameter represented the overall ratio of leaf width to leaf length. Using this method, we compared some leaf parameters (leaf shape, number of leaves per plant, ratio of total leaf weight to aboveground weight per plant, and total leaf area per plant) of four bamboo species of genus Indocalamus Nakai (I. pedalis (Keng) P.C. Keng, I. pumilus Q.H. Dai and C.F. Keng, I. barbatus McClure, and I. victorialis P.C. Keng). We also explored the possible correlation between spatial density and total leaf area per plant using log‐linear regression. We found that the simplified Gielis equation fit the leaf shape of four bamboo species very well. Although all these four species belonged to the same genus, there were still significant differences in leaf shape. Significant differences also existed in leaf area per plant, ratio of leaf weight to aboveground weight per plant, and leaf length. In addition, we found that the total leaf area per plant decreased with increased spatial density. Therefore, we directly demonstrated the self‐thinning rule to improve light interception.     

Do defoliating insects distinguish between symmetric and asymmetric leaves within a plant?

1. Plants represent a highly heterogeneous resource for herbivores. One dimension of this heterogeneity is reflected by the within‐plant variation in the leaf fluctuating asymmetry (FA), i.e. in the magnitude of the random deviations from the symmetry in leaf shape. 2. This study is the first to test experimentally the hypothesis that variation in the quality of individual leaves for defoliating insects (11 species) within a plant (seven tree and shrub species) is associated with the FA of these leaves. 3. It was demonstrated that specialist defoliators generally distinguish between nearly symmetric (low FA) and highly asymmetric (high FA) leaves, but do not distinguish between discs cut from these leaves. Low‐FA leaves of Salix caprea, Salix myrsinifolia and Populus tremula were of better quality for insects than high‐FA leaves, as demonstrated by both preference tests and performance trials. By contrast, high‐FA leaves of Betula pubescens were of better quality for insects than low‐FA leaves, whereas insects feeding on Alnus incana showed similar responses to high‐ and low‐FA leaves. 4. It is concluded that insect herbivores can distinguish between leaves with high and low FA, and that FA may be associated with the quality of an individual leaf for insects, although the direction and strength of the effect of leaf FA on insect preference and performance vary among study systems. The ecological significance of substantial within‐plant variation in leaf FA remains to be explored.     

New insights into leaf and fine‐root trait relationships: implications of resource acquisition among 23 xerophytic woody species

Functional traits of leaves and fine root vary broadly among different species, but little is known about how these interspecific variations are coordinated between the two organs. This study aims to determine the interspecific relationships between corresponding leaf and fine‐root traits to better understand plant strategies of resource acquisition. SLA (Specific leaf area), SRL (specific root length), mass‐based N (nitrogen) and P (phosphorus) concentrations of leaves and fine roots, root system, and plant sizes were measured in 23 woody species grown together in a common garden setting. SLA and SRL exhibited a strong negative relationship. There were no significant relationships between corresponding leaf and fine‐root nutrient concentrations. The interspecific variations in plant height and biomass were tightly correlated with root system size characteristics, including root depth and total root length. These results demonstrate a coordinated plant size‐dependent variation between shoots and roots, but for efficiency, plant resource acquisition appears to be uncoupled between the leaves and fine roots. The different patterns of leaf and fine‐root traits suggest different strategies for resource acquisition between the two organs. This provides insights into the linkage between above‐ and belowground subsystems in carbon and nutrient economy.     

竹子箨叶形态性状的种间差异及其与竹笋食味品质指标的关系

竹笋是大众喜爱的森林蔬菜,其食味品质存在种间差异,且出土前后品质存在明显的变异.箨叶是竹笋的重要器官,居于箨鞘顶端,是竹笋出土时最先感光部位,是否与竹笋食味品质变异密切相关?目前尚不清楚.为此,以同一地点、立地条件和人工干扰措施一致的6个属22个竹种为对象,分析了不同竹种箨叶形态性状和竹笋食味品质指标,为揭示竹笋食味品...     

中国竹类植物基本形态学功能性状的比较

竹类植物作为一种克隆植物, 无次生生长过程, 具有独特的生长和繁殖特性。但有关不同类群竹类植物功能性状的变异规律所知甚少。本文以在中国分布的34属534种竹类植物为研究对象, 从Flora of China中收集和整理其秆高、直径、节间长、竹壁厚、叶长、叶宽等基本形态学功能性状, 根据竹类植物生物学特性, 按地下茎划分为丛生、散生和混生3个类群, 按出笋季节划分为春、夏、秋、冬4个类群, 按分布范围划分为中国特有(371个中国特有种)和非特有2个类群, 再采用方差分析和多重比较探讨不同类群竹类植物在基本形态学性状上的分异格局, 采用主成分分析揭示各个功能性状之间的内在关联, 剖析不同类群竹类植物功能性状的变异。结果表明: 丛生竹、散生竹和混生竹之间功能性状差异显著, 丛生竹具有最大的秆高、直径、节间长、竹壁厚, 最小的叶长和叶宽, 散生竹次之, 而混生竹则具有最小的秆性状和最大的叶性状。中国特有种在秆高、直径、竹壁厚、叶长方面显著小于非特有种。竹类植物秆高、直径、节间长、竹壁厚之间均呈显著正相关, 叶长和叶宽之间存在显著正相关。竹类植物在垂直方向上的大小性状(主要包括直径、秆高和竹壁厚)在第一主轴具有较大的贡献率, 而在水平方向上的叶片功能性状(叶长和叶宽)在第二主轴上贡献率最大。由此可见, 竹类植物在水平方向和垂直方向上对光资源的捕获差异可能是驱动竹类植物系统演化、特有性分布和出笋季节差异的关键因素。     

Nutrient contents predict the bamboo‐leaf‐based diet of Assamese macaques living in limestone forests of southwest Guangxi,China

Determining the nutrient factors influencing food choice provides important insight into the feeding strategy of animals, which is crucial for understanding their behavioral response to environmental changes. A bamboo‐leaf‐based diet is rare among mammals. Animals’ food choice and nutritional goals have been explained by several frameworks; however, the influence of nutrients on food choice in bamboo‐leaf‐based macaques is not yet available. Assamese macaques (Macaca assamensis) inhabiting limestone forests are characterized by such a bamboo‐leaf‐based diet, predominantly consuming young leaves of Bonia saxatilis, a shrubby, karst‐endemic bamboo. We studied the feeding behavior of one group of Assamese macaques using instantaneous scan sampling in limestone forests of the Guangxi Nonggang National Nature Reserve in southwest Guangxi, China. We compared the nutrient content of staple food and nonfood items and examine the role of key nutrients in the food selection of macaques. Our results showed that young leaves of bamboo B. saxatilis contained more water, crude protein, phosphorus, and less tannin than nonfood items. Furthermore, staple foods contained a higher content of water and less content of calcium than nonfood items. More specifically, quantities of water, crude protein, calcium, and phosphorus in food items were critical factors affecting feeding time on a specific plant item. Our results suggest that young bamboo leaves could meet macaques’ required protein and water intake, while enabling them to maintain their mineral balance, consequently facilitating to maintain the primates’ bamboo‐leaf‐diet in the limestone forest. Our findings confirm the effects of nutrient contents in food choice of Assamese macaques, highlighting the importance of the nutrient contents in maintaining their bamboo‐based diet and the need to increase the knowledge on their nutritional strategy adapted to the bamboo‐dominated diet inhabiting the unique limestone habitat.     

Effects of leaf emergence on leaf lifespan are independent of life form and successional status

Abstract The longevity of a leaf is related to the benefit that the plant is able to derive from it. This benefit varies among seasons and as more leaves emerge, such that leaf lifespan can be limited by canopy position rather than physiological age. Using interval‐censored failure time analysis, we investigate leaf lifespan for 34 Mediterranean species in a previously published dataset involving species with different life forms and functional strategies. Failure time regression models were used to determine leaf lifespan, and to investigate how these effects varied among species. Median lifespan estimated for each species with two methods differed by less than 10% on average, but varied from 0.02–19.5% depending on the shape of the underlying failure time distribution. Within shoots, later‐emerging leaves had shorter lifespans for species with longer periods of leaf emergence, and the reverse was true for species with short emergence. Having accounted for the within‐shoot effect, leaves emerging in spring had shorter lifespans, particularly herbaceous species, whereas the reverse was true woody species. These effects were consistent among life forms and successional stages, and consistent with theories of within‐shoot translocation of resources following self‐shading.     

Carbon bio‐sequestration within the phytoliths of economic bamboo species

The rates of carbon bio‐sequestration within silica phytoliths of the leaf litter of 10 economically important bamboo species indicates that (a) there is considerable variation in the content of carbon occluded within the phytoliths (PhytOC) of the leaves between different bamboo species, (b) this variation does not appear to be directly related to the quantity of silica in the plant but rather the efficiency of carbon encapsulation by the silica. The PhytOC content of the species under the experimental conditions ranged from 1.6% to 4% of the leaf silica weight. The potential phytolith carbon bio‐sequestration rates in the leaf‐litter component for the bamboos ranged up to 0.7 tonnes of carbon dioxide (CO₂) equivalents (t‐e‐CO₂) ha^?1 yr^?1 for these species. Assuming a median phytolith carbon bio‐sequestration yield of 0.36 t‐e‐CO₂ ha^?1 yr^?1, the global potential for bio‐sequestration via phytolith carbon (from bamboo and/or other similar grass crops) is estimated to be ～1.5 billion t‐e‐CO₂ yr^?1, equivalent to 11% of the current increase in atmospheric CO₂. The data indicate that the management of vegetation such as bamboo forests to maximize the production of PhytOC has the potential to result in considerable quantities of securely bio‐sequestered carbon.     

Geometric morphometrics and leaf phenotypic plasticity: assessing fluctuating asymmetry and allometry in European white oaks (Quercus)

Because plants are unable to move away from unfavourable habitats and environmental perturbations, leaf phenotypic plasticity facilitates light absorption and gas exchange. Oaks (Quercus spp.) are particularly known for their adaptability and plastic phenotypes, and leaf allometry and developmental instability may represent important mechanisms for their adaptation to environments and evolution. Because of its important role in the adaptation of plant populations to different environments, allometry can be involved in diversifying selection. Developmental instability is related to environmental perturbations and stresses by producing random deviations in structures characterized by bilateral symmetry, such as oak leaves. In addition, developmental instability can also arise from genetic bottlenecks or as a result of hybridization. The splitting of symmetric and asymmetric components of variation and their separate analysis allows the variability in leaf shape traits to be summarized, reducing the variation produced by developmental instability. The geometric morphometric approach is a useful method for the study of leaf asymmetry and allometric patterns. This method provides an important tool for the visualization of shape attributes that characterize species with highly variable leaf phenotypic patterns. In this study, leaf shape and size variability of three white oak species was investigated by means of a two‐dimensional landmark‐based method providing improved knowledge of variance partitioning, species discrimination, fluctuating asymmetry and allometric patterns of variation resulting from the different analyses. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 335–348.     

Floral symmetry is associated with flower size and pollen production but not insect visitation rates in Geranium robertianum (Geraniaceae)

The degree to which fine‐scaled variation in floral symmetry is associated with variation in plant fitness remains unresolved, as does the question of whether floral symmetry is in itself a target of pollinator‐mediated selection. Geranium robertianum (Geraniaceae) is a broadly distributed species whose five‐petaled flowers vary widely with respect to their degree of rotational asymmetry. In this study, we used a naturally occurring population of plants to investigate whether floral rotational asymmetry and leaf bilateral symmetry were phenotypically correlated with a series of fitness‐related traits, and also used an experimental array with model flowers to investigate the preference of insect visitors for varying degrees of floral size and symmetry. We found that leaf asymmetry was not associated with any of the phenotypic traits measured, and that the degree of floral rotational asymmetry was strongly associated with decreased flower size and decreased pollen production. Our experimental arrays showed that insect visitors did not discriminate among model flowers on the basis of size or symmetry alone; however, insect visitors preferentially visited smaller, symmetric model flowers over larger, severely asymmetric model flowers. Taken together, our results suggest that floral and leaf symmetry in G. robertianum are not likely strong indicators of phenotypic quality, and that floral symmetry is unlikely to be a target of pollinator‐mediated selection. However, the relationship between floral asymmetry and pollen production may provide a role for fecundity selection on symmetry in this species. These data importantly add to the growing literature on the adaptive nature of floral symmetry in the wild.     

Foliar form, colour and surface characteristics influence oviposition behaviour of the carrot fly

Various leaf models made of paper were presented to carrot flies, Psila rosae (F.) (Diptera: Psilidae) in choice assays to investigate the effect of non-chemical plant traits on oviposition behaviour. The surrogate leaves differed in colour, shape, surface coating, size and stem length. In the presence of host-plant extracts, physical factors strongly influenced oviposition. Green, yellow and orange three-dimensional models similar in shape to host-plant leaves (pinnately or ternately compound or dissected) and with a thin cover of paraffin wax were most acceptable to the females. Egg-laying was not affected by leaf size, but was negatively correlated with stem length. The results obtained by testing models with simple leaf silhouettes were confirmed in an experiment using more lifelike imitations of real host and non-host leaves. The findings are discussed by an extensive review of similar studies in three other phytophagous fly species (cabbage root fly, onion fly, Hessian fly).     

Reproducibility of fluctuating asymmetry measurements in plants: Sources of variation and implications for study design

Fluctuating asymmetry (FA), i.e. small, non-directional deviations from perfect symmetry in morphological characters, increases under genetic and/or environmental stress. Ecological and evolutionary studies addressing FA became popular in past decades; however, their outcomes remain controversial. The discrepancies might be at least partly explained by inconsistent and non-standardised methodology. Our aim was to improve the methodology of these studies by identifying factors that affect the reproducibility of FA measurements in plant leaves. Six observers used a highly standardised measurement protocol to measure FA using the width, area and weight of the same set of leaves of 10 plant species that differed in leaf size, shape of the leaf margin and other leaf traits. On average, 24% of the total variation in the data was due to measurement error. Reproducibility of measurements varied with the shape of leaf margin, leaf size, the measured character and the experience of the observer. The lowest reproducibility of the width of leaf halves was found for simple leaves with serrate margins and the highest for simple leaves with entire margins and for compound pinnate leaves. The reproducibility was significantly lower for the weight of leaf halves than for either their width or area, especially for plants with small leaves. The reproducibility was also lower for measurements made by experienced observers than by naïve observers. The size of press-dried leaves decreased slightly but significantly relative to fresh leaves, but the FA of press-dried leaves adequately reflected the FA of fresh leaves. In contrast, preservation in 60% ethanol did not affect leaf size, but it decreased the width-based values of FA to 89.3% of the values measured from fresh leaves. We suggest that although reproducibility of leaf FA measurements depends upon many factors, the shape of the leaf margin is the most important source of variation. We recommend, whenever possible, choosing large-leaved plants with entire leaf margins as model objects for studies involving measurements of FA using the width of leaf halves. These measurements should be conducted with high accuracy from images of fresh or press-dried leaves.     

Fluctuating asymmetry in leaves and flowers of sympatric species in a tropical montane environment

Fluctuating asymmetry (FA) represents small, random variations in traits, presumably with bilateral symmetry, and is widely used as a tool to measure developmental instability in plants and animals. Because FA is a quick, simple and reliable measure, it has been frequently used for monitoring levels of environmental stress. This study investigated whether FA can be used as a predictor of individual developmental instability for four sympatric Melastomataceae species. To achieve that aim, 20 individuals of Trembleya laniflora, T. parviflora, Lavoisiera campos‐portoana and Tibouchina heteromalla were marked in southeastern Brazil and monitored before and during the flowering season. The FA index was calculated as the mean of the difference in the width or length between the left and right sides measured for each leaf or flower. All studied species exhibited asymmetry in the leaves and flowers, but the leaves of L. campos‐portoana and the petal width of T. heteromalla exhibited directional asymmetry, also an indicator of developmental instability. The highest level of leaf asymmetry was found in T. heteromalla and on flowers of L. campos‐portoana. None of the studied species exhibited a significant relationship between the FA level of the leaves and flowers on an individual basis, indicating that environmental and/or genetic sources of stress might act differently on different plant traits. For the studied species, measurements of FA can be suggested as useful tools to biomonitor levels of stress experienced by both leaves and flowers within the Melastomataceae family.     

Leaf mass loss in wetland graminoids during senescence

Mass loss of senescing leaves is an important part of plant biomass turnover and has consequences for assessment of ecosystem productivity, ecosystem nutrient use efficiency, and plant nutrient resorption efficiency. Data, however, on mass loss are scarce, and often based on leaf area as the reference base. This leads to an underestimation of the mass loss, as leaf area itself shrinks during senescence. Furthermore, the few existing studies have almost exclusively used woody species. The purpose of the present study was twofold: i) to assess leaf mass loss during senescence in herbaceous species, with the example of five wetland graminoids and, ii) to compare two different methods of mass loss assessment (two species). Assuming that leaf length does not change during senescence, we assessed leaf mass per leaf length prior to and after senescence. We also estimated pre‐senescence leaf mass nondestructively based on leaf length, width and thickness. For Typha latifolia and Carex stricta, two species with graminoid type leaves but contrasting leaf structure, both methods delivered almost identical results. After the first assessment of leaf mass on July 7th, T. latifolia leaf mass initially increased by 13%, and then decreased to be 12% below the original mass after senescence. C. stricta leaf mass remained stable until senescence, but decreased then by 33%. In a second experiment, the mass of 100 mm pieces of leaves was measured before and after senescence. Calamagrostis canadensis, Carex rostrata and C. stricta lost 23–57% of their leaf mass during senescence, whereas Glyceria canadensis did not show any mass loss. We conclude that mass loss of senescing leaves of herbaceous plants can be considerable and should not be neglected in studies of productivity, nutrient use efficiency or nutrient resorption. For species with no shrinking leaf length during senescence, mass loss can be measured with leaf length as the base whereas for others, pre‐senescent mass can be estimated on the basis of leaf dimensions.     

竹叶对萝卜幼苗生长的影响

采用琼脂混粉法研究了22属83种竹叶对萝卜幼苗生长的影响,结果表明:在2g·L^-1的添加浓度下,供试竹叶对萝卜幼苗表现出不同程度的抑制作用,且对根生长的抑制作用大于对胚轴生长和鲜重的抑制作用。刚竹属、簕竹属、大明竹属、牡竹属中,对根长的抑制率在50%以上的竹种分别占70.83%、71.43%、62.50%、85.71%;其它竹属的30种竹叶,有73.33%的竹种对萝卜幼苗根长的抑制率超过50%。淡竹、桂竹、孝顺竹、宜兴苦竹、长叶苦竹、甜龙竹、铺地竹和铁竹等8种竹叶对萝卜幼苗的抑制作用显著,对萝卜根的抑制率均在80%以上。结果对于竹类植物化感作用研究具有参考作用,对拓展竹叶资源的化学利用途径具有一定的指导意义。     

Species Composition of Bacterial Communities Influences Attraction of Mosquitoes to Experimental Plant Infusions

In the container habitats of immature mosquitoes, catabolism of plant matter and other organic detritus by microbial organisms produces metabolites that mediate the oviposition behavior of Aedes aegypti and Aedes albopictus. Public health agencies commonly use oviposition traps containing plant infusions for monitoring populations of these mosquito species, which are global vectors of dengue viruses. In laboratory experiments, gravid females exhibited significantly diminished responses to experimental infusions made with sterilized white oak leaves, showing that attractive odorants were produced through microbial metabolic activity. We evaluated effects of infusion concentration and fermentation time on attraction of gravid females to infusions made from senescent bamboo or white oak leaves. We used plate counts of heterotrophic bacteria, total counts of 4′,6-diamidino-2-phenylindole-stained bacterial cells, and 16S ribosomal DNA (rDNA) polymerase chain reaction–denaturing gradient gel electrophoresis (DGGE) to show that changes in the relative abundance of bacteria and the species composition of bacterial communities influenced attraction of gravid A. aegypti and A. albopictus mosquitoes to infusions. DGGE profiles showed that bacterial species composition in infusions changed over time. Principal components analysis indicated that oviposition responses to plant infusions were in general most affected by bacterial diversity and abundance. Analysis of bacterial 16S rDNA sequences derived from DGGE bands revealed that Proteobacteria (Alpha-, Beta-, Delta-, and Gamma-) were the predominant bacteria detected in both types of plant infusions. Gravid A. aegypti were significantly attracted to a mix of 14 bacterial species cultured from bamboo leaf infusion. The oviposition response of gravid mosquitoes to plant infusions is strongly influenced by abundance and diversity of bacterial species, which in turn is affected by plant species, leaf biomass, and fermentation time.     

中国东部南北样带暖温带区栎属树种叶片形态性状对气候条件的响应

植物叶片的形态性状能够有效地反映生存环境的变化, 并且影响植物的基本行为和功能。该研究通过获取植物标本提供的叶片形态信息, 结合相关分析和标准化主轴分析, 探讨了南北样带暖温带区栎属(Quercus)树种叶片形态性状对气候条件的响应及适应策略。结果表明: 在南北样带暖温带区, 随着气候条件的变化, 栎属树种的叶片形态性状发生显著的变化。随着年平均气温的降低和年日照时数的增加, 栎属树种叶面积增加, 以利于吸收更多的光照辐射, 并增加叶片的边界层阻力, 减少叶片热量的散失; 而叶片分裂程度的增加不仅可以降低热量的散失, 也可以提高叶片液流的波动以增强叶片的生理活动; 叶脉密度随温度的升高、光照强度和降水量的增加而增加, 以响应叶片蒸腾作用的增强, 提高水分的运输能力和叶片的支撑能力。此外, 为适应南北样带暖温带区气候条件的变化, 栎属树种的叶片形成了一系列的形态性状组合, 随着叶面积的增加, 叶柄长度和叶片分裂程度逐渐增加, 而叶脉密度降低; 随着叶片倾向于向长条状发展, 叶柄长度和叶脉密度也随之增加。     

Scale‐dependent trait correlations in a temperate tree community

Recent investigations of relationships among plant traits have generated important insights into plant form and function. However, relationships involving leaf area, leaf shape and plant height remain poorly resolved. Previous work has also focused on correlations between average trait values for individual species. It is unclear whether similar relationships occur within species. We searched for novel plant trait correlations by comparing leaf area, leaf circularity, specific leaf area (SLA) and plant height among 16 common woody plant species from a temperate forest in New Zealand. Analyses were conducted both within species (intra‐specifically) and among species (inter‐specifically) to determine whether trait correlations were scale dependent. Leaf area was unrelated to other leaf traits inter‐specifically. However, leaf area declined with plant height and increased with SLA intra‐specifically. Leaf circularity decreased with plant height inter‐specifically, but increased with plant height intra‐specifically. SLA increased with plant height both inter‐ and intra‐specifically. Leaf circularity increased with SLA inter‐specifically, but decreased with SLA intra‐specifically. Overall results showed that leaf shape, SLA and plant height are interrelated. However, intra‐specific relationships often differed substantially from inter‐specific relationships, suggesting that the processes shaping relationships between this suite of plant traits are scale‐dependent.     

PLANT SIZE AND FORM IN THE UNDERSTORY PALM GENUS GEONOMA: ARE SPECIES VARIATIONS ON A THEME?

This study addressed the hypothesis that phylogenetic changes in plant size at reproductive maturity may have facilitated adaptive radiation of Geonoma species within rain forest understory habitats. Leaf size, leaf form, plant size, and growth form were compared within and among 23 species of Geonoma from lowland and montane rain forest areas of Costa Rica and Colombia. Leaf size was significantly correlated with crown height in 18 of the 21 species examined, and with stem diameter in 17 of the species. In species characterized by a gradual ontogenetic transition from bifid to dissected leaves, shoots with bifid leaves were significantly smaller than shoots with dissected leaves with respect to rachis length, number of plications, and stem diameter. Among species, stem diameter below the crown explained 74% of the variation in leaf size (rachis length). Crown height and stem diameter were positively correlated among clustered species, but not among solitary species or all species combined. Leaf dissection was correlated with crown height among the 17 species with dissected leaves; species with bifid leaves were significantly smaller than species with dissected leaves with respect to leaf size and stem diameter. Solitary species had larger leaves and larger stem diameters than clustered species at the same crown heights. Morphological patterns among species generally followed within-species trends. These patterns suggest that Geonoma species are variants on a generic theme:within and among species, leaf size and complexity of form increase with stem diameter and crown height. Solitary and clustered growth forms appear to be morphologically convergent; within each of these architectural groups, the generic theme still applies. Evolutionary changes in leaf size, leaf form, and plant size, however, have clearly involved other factors in addition to variation in plant size.