Rumex acetosella (sheep's sorrel).

R. acetosella is perennial, reproducing by both creeping roots and seed. It has relatively shallow, extensive slender roots. Early growth is as basal rosettes of leaves. Leaves are 1-8 cm long, smooth, variable in shape but primarily consisting of three lobes, primary lobe is linear to egg-shaped terminating in a point; two secondary lobes appear at the base of the primary lobe and point outwards giving an arrowhead-shape appearance to the leaves which are sour in taste. It has long basal leaf stalks and short-stalked to sessile leaves on the upper stem; a membranous sheath (modified stipules) surrounds the stem above the leaf base. Multiple stems can appear from a single crown growing upright, 15-40 cm in height, slender, branching near the top to form a loose leafless panicle. Flowers are unisexual with male and female appearing on separate plants (dioecious). Males have six stamens on short filaments, females have three styles with branched stellate stigma. Flowers consist of three inner and three outer tepals, appearing red to yellowish, borne on raceme near the top of the stem. Flower stalks are jointed close to the flower. Seeds are three sided (achenes), ca. 1.5 mm in length, shiny reddish brown in colour. A reddish brown hull often adheres to the seed and is rough in texture (Buchholtz et al., 1954; Hitchcock and Cronquist, 1981; Gleason and Cronquist, 1991; Pojar and MacKinnon, 1994; Douglas et al., 1999).

Multi-stemming strategies of Quercus glauca in an evergreen broad-leaved forest: when and where

Aims Multi-stemming supports plants’ resilience to disturbances and then contributes to soil stabilization and forest function, especially in mountain habitats. Many questions remain about (i) the ontogenetic phase at which multiple stems can occur, (ii) how habitat drivers affect multi-stemming and (iii) whether ontogenetic phase and habitat drivers interact. We asked these questions for Quercus glauca (ring-cupped oak), the dominant species and sprouter across large warm-temperate areas of Asia; its multi-stemmed trees reflect individual survival, population regeneration and forest ecosystem stability. Methods In a 5-ha permanent plot of subtropical evergreen broad-leaved forest in eastern China, we examined the temporal patterns and spatial distribution of multi-stemmed trees of Q. glauca within 99 quadrats of 20 m × 20 m. Important Findings There were three temporal modes for multi-stemming among the Q. glauca trees and most of them appeared to produce multiple stems from an early stage. Environmental disturbances related to slope convexity appear to be the main drivers of multi-stemming of Q. glauca. Moreover, the closer to the ridge, the earlier the multi-stemming occurs. Thus, also for other woody species in other forests and climate zones, ontogeny and environmental drivers promoting disturbance (not only geomorphology, but also extreme weather events, soil drought, fire), as well as soil fertility, need to be considered in combination to better understand multi-stemming and its consequences for community structure.

Two new species of the genus Chironephthya (Octocorallia, Alcyonacea, Nidaliidae, Siphonogorgiinae) from the Gulf of Thailand

Two new species of the genus Chironephthya, C. sirindhornae sp. nov. and C. cornigera sp. nov., are described based on three specimens collected from the Gulf of Thailand. Both species are well distinguished from the previously described species of the genus Chironephthya by their colonies consisting of multiple stems that stand upright from a common base, and by a significantly thinner canal wall without large spindles. As a result of phylogenetic analyses using COI, mtMutS, and 28S rDNA sequences of these two species, these three specimens constituted an independent small clade within a large mixed clade of Siphonogorgia and Chironephthya, with the two species slightly different from each other. The discrepancy in the morphology suggested the erection of a new genus to accommodate these species, however, as the subclade was included in a large mixed clade of Siphonogorgia and Chironephthya, we place these species within genus Chironephthya. Our results further highlight the continuing confusion between Siphonogorgia and Chironephthya, and demonstrate the need for taxonomic revision of these genera.

Notes on the genus Zeravschania (Apiaceae) with description of two new species from Afghanistan and Iran

Two species of Apiaceae are described as new to science: Zeravschania khorasanica from the Khorasan Province, eastern Iran, and Z. podlechii from the Ghor Province, central Afghanistan. Zeravschania khorasanica is related to Z. regeliana and Z. scabrifolia, but differs in rigid remains of petioles and sheaths, deeply laciniate ultimate segments of leaves, and broad-keeled ribs of mericarps. Zeravschania podlechii differs from other species of the genus in multiple stems, short internodes, dichotomous branching, and an unusual life form (сushion plant). In addition, Z. knappii is transferred to the genus Dichoropetalum on the basis of morphological evidence.

Crown Area as a Parameter for Biomass Estimation of Croton sonderianus Müll. Arg.

ABSTRACT Current tree biomass estimation techniques generally use remote sensing data and allometric models for validation, which relate non-destructive parameters to plant biomass, usually employing diameter at the plant base or breast height and plant height. In the Caatinga Biome, many plants present multiple stems, thus making it difficult to measure the plant diameter, and lost branches, which are difficult to correct for. Hence, there is a need for suitable models for Caatinga plants, as well as studies on the possibility of using other parameters. For this study, plant and branch basal diameter, plant height, and crown area of Croton sonderianus plants were measured, and plants were also collected and weighed. Several classic models and their variations were tested. The best models were variations of Naslund (R2 = 0.92; rmse = 1,221) and Schumacher & Hall (R2 = 0.92; rmse = 1,217). Plant height and crown area enables a better biomass estimation than using plant or branch basal diameter.

Evidence for clonality, breeding system, genetic diversity and genetic structure in large and small populations of Melaleuca deanei (Myrtaceae)

Melaleuca deanei F.Muell. is a rare, serotinous shrub with a naturally restricted distribution centred over the sandstone ridges around Sydney. Sexual reproduction and seedling recruitment occur rarely, and plants appear to spread and persist largely by clonal root suckering. A potentially outcrossing breeding system, combined with extensive clonality, place M. deanei at a high risk of reproductive failure. Knowledge of the extent of its clonality and breeding system, and an understanding of the distribution and abundance of genetic diversity within and among its populations, will assist conservation management. The present study reports on the extent of clonality, breeding system, levels of genetic diversity, and population differentiation within small, medium and large populations of M. deanei from the northern and southern distribution regions. Multiple stems were found to comprise single genets up to ~10 m diameter on the ground and molecular evidence points to an outcrossing breeding system. Genetic diversity was positively correlated with population size and significant genetic differentiation was shown between northern and southern regions using clustering analyses. Recommendations for in situ and ex situ conservation management based on these results are provided.

AVOCADO SEEDLINGS MULTIPLE STEMS PRODUCTION

ABSTRACT This study aimed to evaluate the potential of multi-stems in avocado seeds according to their mass as well as the adventitious rooting of multi-stem budding with or without the use of auxin. The research was carried out at the Vegetation House of Federal Institute of Espírito Santo, Campus Santa Teresa -ES, with seeds of different masses: <60 g, 61 to 80 g, 81 to 100 g and >100 g, in which each experimental unit was made of five seeds, distributed within five repetitions, under a completely randomized design. The seeds were put to germinate and the percentage number of emergence and multiple stems were evaluated. After 150 days, the following evaluations were carried out: survival of rooted cuttings; number of leaves; stem diameter; root length; root volume; root and shoot fresh mass; root and shoot dry mass; shoot height; absolute growth and shoot growth rate; shoot dry weight/root dry mass ratio; shoot height/stem diameter ratio; shoot height/root length and Dickson's quality index ratio. Avocado seeds with mass over 100 g and between 81-100 g presented higher percentage of multiple stems. Rods over 20 cm that were not treated with IBA (indole-3-butyric acid) resulted on avocado plants of better quality. The use of IBA (2000 mg L-1) does not affect the rooting and growth of avocado's multi-stem plants.

Tropical montane cloud forest: environmental drivers of vegetation structure and ecosystem function

Tropical montane cloud forests (TMCF) are characterized by short trees, often twisted with multiple stems, with many stems per ground area, a large stem diameter to height ratio, and small, often thick leaves. These forests exhibit high root to shoot ratio, with a moderate leaf area index, low above-ground production, low leaf nutrient concentrations and often with luxuriant epiphytic growth. These traits of TMCF are caused by climatic conditions not geological substrate, and are particularly associated with frequent or persistent fog and low cloud. There are several reasons why fog might result in these features. Firstly, the fog and clouds reduce the amount of light received per unit area of ground and as closed-canopy forests absorb most of the light that reaches them the reduction in the total amount of light reduces growth. Secondly, the rate of photosynthesis per leaf area declines in comparison with that in the lowlands, which leads to less carbon fixation. Nitrogen supply limits growth in several of the few TMCFs where it has been investigated experimentally. High root : shoot biomass and production ratios are common in TMCF, and soils are often wet which may contribute to N limitation. Further study is needed to clarify the causes of several key features of TMCF ecosystems including high tree diameter : height ratio.

Prosperity of Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) plantations in relation to the shelter

The study evaluates the mortality, growth and qualitative characteristics of Douglas fir transplants planted out on clear-cut areas with different shelter. We assessed 11 clearings situated in the Forest Site Complex 4K &ndash; acidic beech (Fagetum acidophilum). The young trees were assessed 3 years after planting for the following parameters: total shoot length, increment, root collar diameter, number of multiple stems, stem curvature, crown form, length of needles, colour of needles and frost damage. The lowest mortality and the best growth of Douglas fir plants were recorded in small, sheltered gaps. Large, unsheltered gaps showed low survival, slower growth and poor vitality of plants. &nbsp;