Search results for "Inflorescence"

Low fruit set in a dioecious tree: pollination ecology of Commiphora harveyi in South Africa

2005

Dioecious plant species differ in floral morphology and rewards between females and males. Pistillate flowers on female plants often lack pollen and can be less attractive to pollinators, which can have consequences for the visitation rates of the sexes. We studied the pollination ecology of the dioecious tree Commiphora harveyi in a coastal scarp forest in eastern South Africa. Floral display, visiting insect species, visitation rate and natural fruit set were recorded. Additionally, we pollinated flowers by hand to determine experimental fruit set. We found that male trees had more and larger flowers per inflorescence than female trees. Both sexes produced nectar in low amounts. During 20…

Analysis of Phenolic Compounds in Commercial Cannabis sativa L. Inflorescences Using UHPLC-Q-Orbitrap HRMS

2020

Industrial hemp (Cannabis sativa L. Family Cannabaceae) contains a vast number of bioactive relevant compounds, namely polyphenols including flavonoids, phenolic acids, phenol amides, and lignanamides, well known for their therapeutic properties. Nowadays, many polyphenols-containing products made of herbal extracts are marketed, claiming to exert health-promoting effects. In this context, industrial hemp inflorescence may represent an innovative source of bioactive compounds to be used in nutraceutical formulations. The aim of this work was to provide a comprehensive analysis of the polyphenolic fraction contained in polar extracts of four different commercial cultivars (Kompoti, Tiborszal…

Pollination ecology of the dioecious tree Commiphora guillauminii in Madagascar

2004

In dioecious plant species differences in morphology and resources between female and male flowers can have consequences for flower visitation rates. Female flowers sometimes lack pollen and can be less attractive to pollinators than male flowers. We studied the pollination ecology of the dioecious tree Commiphora guillauminii in a dry deciduous forest in western Madagascar. We recorded floral display, visiting insect species and visitation rates for female and male trees. The results showed that female trees produce significantly larger but fewer flowers per inflorescence than male ones. Number of flowers per tree did not differ between the sexes. During 270 observation-hours we observed 1…

Characterization of an Italian biotype of clary sage (Salvia sclarea L.) grown in a semi-arid Mediterranean environment

2002

An Italian spontaneous biotype of clary sage (Salvia sclarea L.) was evaluated for its suitability to be cultivated in a semi-arid area and for the influence of these growth conditions on the essential oil composition. Seeds gathered from a spontaneous biotype were sown directly in the field, using a seeding density calculated to achieve a plant population of 7 plants/m2. Essential oils from the inflorescences and leaves of plants harvested at full flowering and early seed ripeness stages were obtained by steam distillation and characterized by GC and GC–MS. The plants showed a good tolerance to the semi-arid growth conditions, yielding more than 700 flowers/plant and about 21 g seeds/plant…

Silene crassiuscula (Caryophyllaceae), a new species from Sicily

2015

Silene crassiuscula,, a new species of S. sect. Dipterosperma, is described and illustrated from North-Western Sicily. It is an annual halophyte with succulent growing on carbonatic or calcarenitic rocks of coastal stands. From the morphological point of view , S. crassiuscula appears to be similar to the species belonging to the S. colorata group especially to S. nummica, from Sardinia, from which it differs in several features chiefly regarding the habit, leaves, inflorescences, floral pieces and seed micro-morphology. An analytical key of the taxa belonging to this section is also provided.

Unisexual flowers as a robust synapomorphy in Cariceae (Cyperaceae)? Evidence for bisexual flowers in Schoenoxiphium

2012

Abstract Cariceae, the largest tribe within Cyperaceae, comprises about 2000 species in five genera. Cariceae is usually considered to be distinct from other Cyperaceae by the presence of exclusively unisexual flowers and by the arrangement of the pistillate flowers in single-flowered spikelets that are enclosed by the flask-like spikelet prophyll (utricle or perigynium). The nature of several morphological features of the Cariceae inflorescence remains controversial. The staminate reproductive units, as well as earlier reported bisexual reproductive units in Schoenoxiphium have been considered to be reduced partial inflorescences, or flowers. Aims of this study are to test both interpretat…

A new species of Agrostis (Gramineae) in the A. alpina complex

2000

Abstract A new species of Agrostis L. ( A. barceloi ) is described from the northern mountains of Mallorca (Balearic Islands). The new taxon belongs to sect. Agrostis and is mainly related to A. alpina Scop. and A. schleicheri Jord. & Verl. on morphological grounds. However, A. barceloi differs from A. alpina by its narrowly-lanceolate inflorescence, with panicle branches erect during and after anthesis, non-scabrid leaves, and by smaller lemmas and others. The new species is distinguished from A. schleicheri by the smaller spikelets, lemma, palea, and anthers. In addition, A. barceloi is tetraploid (2 n =28), and differs cytologically from the diploid A. alpina (2 n =14) and the hexaploid …

Functional implications of the staminal lever mechanism in Salvia cyclostegia (Lamiaceae)

2011

Flower morphology and inflorescence architecture affect pollinator foraging behaviour and thereby influence the process of pollination and the reproductive success of plants. This study explored possible ecological functions of the lever-like stamens and the floral design in Salvia cyclostegia.Flower construction was experimentally manipulated by removing either the lower lever arms or the upper fertile thecae of the two stamens from a flower. The two types of manipulated individuals were intermixed with the control ones and randomly distributed in the population.Removing the sterile lower lever arms significantly reduced handling time per flower of the main pollinator, Bombus personatus. I…

Typology of inflorescences

1965

Sex ratio and spatial distribution of male and female Antennaria dioica (Asteraceae) plants

2011

Sex ratio, sex spatial distribution and sexual dimorphism in reproduction and arbuscular mycorrhizal colonisation were investigated in the dioecious clonal plant Antennaria dioica (Asteraceae). Plants were monitored for five consecutive years in six study plots in Oulanka, northern Finland. Sex ratio, spatial distribution of sexes, flowering frequency, number of floral shoots and the number and weight of inflorescences were recorded. In addition, intensity of mycorrhizal fungi in the roots was assessed. Both sexes flowered each year with a similar frequency, but the overall genet sex ratio was strongly female-biased. The bivariate Ripley’s analysis of the sex distribution showed that within…