Morphological variability of Veronica arguteserrata Regel & Schmalh. – new adventive species in Dnipro area

In the Dnipro area, Veronica arguteserrata is a new adventitious species of Asian origin from the family Plantaginaceae Juss., growing in the same ecological conditions – in shaded areas with moderate anthropogenic impact due to trampling, on loose soils and on parchment plots. The species is ephemeral: begins to grow in the second half of April, blooms in mid-May, bears fruit at the end of the same month, turns yellow in June and dies. We used 160 plants to study the morphological and ecological variability of Veronica arguteserrata. For analysis, we measured plant height, root length, length of the first and second internodes, length and width of leaf blade, number of peduncles, number of flowers, width and length of bract, corolla diameter, length and width of the fruits, number of seeds in the nest and number of fruits on the plant. The average values of all components were determined, the errors and population density, the number of individuals per 0.01 m2 were determined. Using a grid of 20 × 10 cm, divided into eight squares 5 × 5 cm, calculated the density of plants in tenfold repetition. The accuracy of density estimation, calculated as the ratio of error of the arithmetic mean to the arithmetic mean and expressed as a percentage, was 3.8–6.3%. The accuracy of assessment of other traits ranged from 2.2 to 7.5%, which is quite acceptable for field research. Analysis of the data showed that Veronica arguteserrata in the study area forms a fairly dense density of grasses, in which almost no other species are immersed. With increasing density, there is a tendency to increase the length of the first internode and reduce the area of the leaf blade, the number of peduncles, flowers and fruits on individuals. Within the parks, the plants were mowed at the end of the growing season. Probably due to mowing, as well as a slightly greater impact of trampling, the density of park populations is lower than on the highway near buildings. Synecological analysis showed that in the conditions of Dnipro area Veronica arguteserrata is a xeromesophyte, mesotroph, sciogeliophyte and ruderant. In the studied phytocenoses with increasing population of Veronica arguteserrata there is a tendency to decrease plant height, length of the second internode, length and width of the leaf blade, number of peduncles and flowers, length and width of bracts, peduncle length, corolla diameter and corolla diameter increase and box length. The highest variability was observed in the following signs from the vegetative sphere of Veronica arguteserrata plants: root length, leaf blade length, in the generative sphere: the number of flowers and of fruit on the plant. It is these features that make the largest share in the morphological variability of the studied species and determine its overall ecological and morphological plasticity. As a result of analysis of variance, the influence of population density on morphometric characteristics of plants was statistically proved. The population density has the greatest influence on the following features of the vegetative sphere: the length of the first internode and the length of the leaf blade; in the generative sphere: the diameter of the corolla and the length of the bract. Thus, the variability of these traits can be considered as a mechanism of intra-population morphological adaptations of the new adventitious species Veronica arguteserrata in the Dnipro area. The new adventitious species needs further monitoring studies to assess the level of impact on the ecosystems of Dnipro area.

The study of online digitized specimens revalidates Andersonglossum boreale as a species different from A. virginianum (Boraginaceae)

Cynoglossum virginianum L., now transferred to the genus Andersonglossum as A. virginianum (L.) J.I.Cohen, has been traditionally considered to be formed by two infraspecific taxa: var. virginianum, and var. boreale (Fernald) Cooperr. The var. boreale was originally described as an independent species, Cynoglossum boreale Fernald, and remained treated as such until its combination as a variety of C. virginianum. However, no analysis exists that objectively compares both taxa in order to properly assess their taxonomic relationships. We performed a morphometric study to help elucidate their taxonomy. We found that both species are distinguishable using a few characters, despite slight overlap in nutlet length, corolla diameter, and calyx length, all traditionally considered to identify both taxa. The relatively large amount of variation in calyx dimensions seems to be the reason for most recent authors treating the two taxa at varietal rank. We provide the new combination Andersonglossum boreale (Fernald) Jim.Mejías, J.I.Cohen & Naczi to allow treating Cynoglossum boreale as a distinct species under its new generic circumscription.

Flower, fruit phenology and flower traits inCordia boissieri(Boraginaceae) from northeastern Mexico

We characterized variations inCordia boissieriflowers and established if these variations occur between plants or between flowering events. Flowering and fruiting was measured for 256 plants. A GLM test was used to determine the relationship between flowering and fruit set processes and rainfall. We performed measurements of floral traits to detect variations within the population and between flowering events. The position of the anthers with respect to the ovary was determined in 1,500 flowers. Three out of four flowering events of >80%C. boissieriplants occurred after rainfall events. Only one flowering event occurred in a drought. Most plants flowered at least twice a year. The overlapping of flowering and fruiting only occurred after rainfall. Anthesis lasted three-to-five days, and there were two flower morphs. Half of the plants had longistylus and half had brevistylus flowers. Anacahuita flower in our study had 1–4 styles; 2–9 stamens; 6.5–41.5 mm long corolla; sepals from 4.5–29.5 mm in length; a total length from 15.5–59 mm; a corolla diameter from 10.5–77 mm. The nectar guide had a diameter from 5–30.5 mm; 4–9 lobes; and 5 distinguishable nectar guide colors. The highest variation of phenotypic expression was observed between plants.

EVALUATION OF FLORAL CHARACTERISTICS OF MELON HYBRIDS (Cucumis melo L.) IN POLLINATOR ATTRACTIVENESS

ABSTRACT Floral morphology and biology are important characteristics for plant-pollinator interactions and may influence the behavior of these agents. This study aimed to determine which floral attributes of different melon hybrids influence this interaction and, consequently, their attractiveness in simultaneous crops. The study was conducted in the region of Petrolina, State of Pernambuco (PE)/Juazeiro, State of Bahia (BA) and Mossoró, State of Rio Grande do Norte (RN), in areas with the following melon hybrids: Yellow type, Piel de Sapo, Cantaloupe and Galia. For studies on floral morphology and biology, hermaphrodites and male flowers of each hybrid were analyzed for their size and nectar chamber size, pollen and nectar production, anthesis time and flower lifespan. Floral visitors were observed simultaneously in hybrids of three types of melon, from 5:00 a.m. to 6:00 p.m., in the two study sites. Evaluations of the corolla diameter and flower height indicated that the hermaphrodite flowers were larger in size than male flowers in all types of melon investigated, in both study sites. As for nectar chamber, male flowers are larger in width, but smaller in height, compared to hermaphrodite flowers. Regarding the volume of nectar, differences were found between floral types for the hybrids evaluated, in the two study sites; the hermaphrodite flowers produced 2-7 times more nectar than male flowers in all studied hybrids. Observations of visits of Apis mellifera to areas with simultaneous flowering of the three types of melon demonstrated differences in the frequency of visits between hybrids, floral type and foraged resource. Flowers of the hybrids Piel de Sapo and Cantaloupe exhibited larger corolla diameter, larger dimensions of the nectar chamber and greater supply of resources for foraging, which could explain the higher number of visits of bees to their flowers in the sites studied.

Does Altering Local Water Availability for an Invasive Plant (Raphanus raphanistrum) Affect Floral Morphology and Reproductive Potential?

Abiotic environmental variation can have dramatic effects on plant floral morphology and nectar or pollen rewards. In response, pollinators may change their foraging behavior and distribution and if pollinators change their foraging behavior or distribution, this could have dramatic effects on the reproductive success of plant populations. To start tackling this problem, we measured the response of floral morphology (corolla diameter, stamen length, and ovule number) of Raphanus raphanistrum to experimental manipulations of field soil moisture. As soil moisture increased, corolla diameter and anther length grew. We expect these changes to provide more visitation rewards for insects in moist conditions. Therefore, water availability influences growth and development of flowers, and may have dramatic effects on insect community dynamics. KEYWORDS: Floral Rewards, Climate, Rain-out Shelters, Flower Morphology, Raphanus raphanistrum, Brassicaceae

Flowering and mating system in hybridizing Carpobrotus (Aizoaceae) in coastal California

Patterns of flowering and pollination visit of Carpobrotus spp. were examined to determine the hybridization potential between the introduced succulent perennial Carpobrotus edulis and its native congener, Carpobrotus chilensis, in coastal California. Both species flower from March to July and both are visited by the same Thysanoptera and Coleoptera taxa. Flowers from hybrid-appearing individuals were intermediate in corolla diameter. Emasculation and bagging experiments suggest that C. edulis and hybrid morphotypes have facultative agamospermia, whereas C. chilensis has facultative self-fertilization. Emasculated C. chilensis did not set seeds. Pesticide application and flower bagging suggest that 80% of seed set in self-pollinated C. chilensis flowers is mediated by thrips. Our results suggest that there is high potential for natural hybridization in Carpobrotus species in California and that Carpobrotus populations can persist without cross-pollination.Key words: Carpobrotus, exotic species, facultative agamospermia, hybrid fitness, invasion, pollination preference.

Control of Salpiglossis sinuata Height with Plant Growth Regulators

Salpiglossis sinuata R. et P., a floriferous member of the Solanaceae, was studied for potential as a flowering potted plant when modified by growth retardants. Seedlings of an inbred line P-5 were covered with black cloth for an 8-hour photoperiod to permit vegetative growth to ≈16 -cm-diameter rosettes. Plants were then exposed to an 18-hour photoperiod for the duration of study. Flowering occurred 40 days after the plants were transferred to long days. Neither spray applications of uniconazole at 10, 20, 40, or 100 ppm, nor chlormequat chloride at 750, 1500, or 3000 ppm significantly retarded plant height. Applications of daminozide, ranging in concentration from 1000 to 5000 ppm, alone and in combination with chlormequat chloride, were effective at retarding plant height; however, concomitant restriction of corolla diameter was frequently observed. Chemical names used: 2-chloro- N,N,N -trimethylethanaminium chloride (chlormequat chloride); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); and (E) -1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl) -1-penten-3-01 (uniconazole).