Popiela et al. (2015) Acta Botanica Gallica

Popiela A., Łysko A., Molnár V.A., Kącki Z., Lukács B. A.(2015): Elatine triandra Schkuhr (Elatinaceae) in Europe, with special emphasis on the central part of thecontinent. – Acta Botanica Gallica – Botany Letters 162 DOI:10.1080/12538078

Abstract

Elatine trianda Schkuhr is the most widespread species within the genus Elatine L.; it can be found in all continents, except Antarctica, but the majority of the locations have been recorded in Europe. The study is based on an extensive dataset of literature, herbaria and web data, which spans the period 1828–2012. The range of the species in Europe is disjunctive; it covers the southern and western parts of the Central European Plain and the northern shores of the Baltic Sea, it can also be found along some river valleys. In Central Europe many localities especially isolated ones in northern part of the range are historical now. According to the dataset we determined that E. triandra can be observed between May and October. We also found a remarkable historical decrease of observation time. We found that species observation has a near significant shift since 1828 that correlates to changes in environmental variables. Depending on the environmental conditions individuals of the taxon could develop in two forms: terrestrial and aquatic. The aquatic form is characterized by twice longer stems and internodes, and also almost twice longer lamina and petiola. E. triandra seeds show consistent characteristics both in terms of forms and populations. Our studies show that the best diagnostic feature, in addition to the construction of flowers, are size, shape and surface structure of seeds. In Central Europe E. triandra occurs exlusively in communities classified to the Isoëto-Nano-Juncetea, however the number of species characteristic for the class and lower syntax in patches decreases from north to south of the continent.

Keywords

chorology, ephemerophyte, Isoëto-Nano-Juncetea, phytogeography, vegetation, morphology, maps, phenology

Lovas-Kiss et al. (2015) Acta Societatis Botanicorum Poloniae

Lovas-Kiss Á., Sonkoly J., Vincze O., Green A.J., Takács A. & Molnár V. A. (2015): Strong potentialfor endozoochory by waterfowl in arare, ephemeral wetland plant species (Astragalus contortuplicatus, Fabaceae). – Acta Societatis Botanicorum Poloniae 84(3): 321–326.

Abstract

It was proposed previously that passive dispersal by migratory aquatic birds explain the widespread distribution of many wetland organisms. Several experimental studies have shown that many widespread wetland plant species can be readily dispersed within the guts of Anatidae. However, it is unclear whether plants with a more restricted distribution are able to disperse via waterbirds. This paper addresses the dispersal ability and germination ecology of the little-known Hungarian milkvetch Astragalus contortuplicatus, which occurs on banks of continental rivers and has a limited and unpredictable distribution. To test whether limited capacity for endozoochory by waterfowl could explain the sporadic appearance of this species, we force-fed ten captive mallards (Anas platyrhynchos) with 100 milkvetch seeds each. Droppings were collected for up to 45 h after feeding. Intact and viable seeds were found in the droppings of each mallard, and altogether 24.7% of seeds fed were recovered intact. The proportion of retrieved seeds that germinated (27.0%) was significantly higher than that of untreated control seeds (0.5%), but significantly lower than that of mechanically scarified seeds (96.0%). Retrieved seeds that germinated developed into healthy mature plants. Given the average flight velocity of mallards, seeds of A. contortuplicatus may travel up to 1600 km inside the digestive tract of migrating individuals. Our results suggest that avian vectors may be more important for the dispersal of rare higher plants (especially those with a hard seed-coat) than hitherto considered. Moreover, they suggest that rarity does not necessarily indicate limited dispersal ability, and may instead be explained by specific habitat requirements.

Keywords

Anas platyrhynchos, germination experiment, mallard, ornitochory, seed dispersal, seed ecology, seed viability

Molnár V. et al. (2015) Preslia

Molnár V.A., Sonkoly J., Lovas-Kiss A., Fekete R., Takács A., Somlyay L. & Török P. (2015): Seed of the threatened annual legume, Astragalus contortuplicatus, can survive over 130 years of dry storage. – Preslia 87(3): 319–328.

Abstract

Long-term seed viability is of crucial importance for short-lived species, since persistent seed banks can buffer the fluctuations in the establishment of plants from year to year. Temporarily flooded habitats are an unpredictable environment for plants, and for some species the only chance they have of surviving is the formation of persistent seed banks. Astragalus contortuplicatus is an annual species of periodically flooded habitats and is considered an endangered species in Hungary. Altogether 1993 seeds of this species were tested in a germination experiment: 1200 were freshly harvested and 793 were collected from herbarium specimens of various ages. Seed viability was tested using the germination method. The freshly harvested seeds were used for selecting the best out of seven frequently used dormancy-breaking methods for this species. The highest percentage of germination was recorded for the combined treatment of scarification and light. Thus, this method was used to test the viability of the seeds collected from herbarium specimens. The oldest seeds that germinated were 131 years old. Until now there are no records of seeds of herbaceous legumes germinating that are more than 100 years old. This record is the 9th oldest of all the literature records of viable seeds originating from biological collections. All the seeds that germinated developed into healthy, fertile plants, the seeds of which also readily germinated. Fitted linear regression showed a significant negative relationship between seed age and percentage germination. Based on this linear regression the calculated theoretical maximum viability is 309 years. Our results suggest that seeds of A. contortuplicatus stored in collections can be successfully used in this species’ reintroduction for conservation purpose, to areas in which the plants were collected.

Keywords

biological collections, Fabaceae, hard seeds, herbarium, Hungary, physical dormancy, scarification, persistence, seed longevity, seed storage