53 research outputs found
Notes on Ipomoea L. (Convolvulaceae) in Cuba and neighbouring islands with a checklist of species found in Cuba
An updated checklist of species of Ipomoea L. found in Cuba is presented with analysis of the different elements represented. I. alterniflora Griseb. is defined broadly to include I. obtusata Griseb. and I. excisa Urb. and its differences from the little-known I. cubensis (House) Urb. are discussed. I. calophylla C. Wright ex Griseb. is reinstated as the correct name for the species generally known as I. lacteola House. I. praecox C. Wright is recognised as a distinct species from I. argentifolia A. Rich. and images are provided to help distinguish the two species. I. flavopurpurea Urb. and I. dajabonensis Alain are shown to be conspecific with I. longeramosa Choisy, whose disjunct distribution is mapped and discussed. The little-known I. montecristina Hadač is described and illustrated and the cited collections show it to be locally common in the Guantánamo region. I. microdonta J. R. I. Wood and Scotland is described as new from Camagüey in central Cuba. Eight species endemic to Cuba collected by Ekman and described by Urban in 1924 – 25 are evaluated but only two, I. balioclada Urb. and I. erosa Urb., are deemed to warrant recognition as distinct endemic species. The origin and typification of I. horsfalliae Hook. are discussed and an epitype designated. Cultivated plants named I. horsfalliae occur in many tropical countries including Cuba but their extreme variation suggests hybrid origin. Four species from Jamaica, I. rubella House, I. lineolata Urb., I. carmesina Proctor and the Jamaican plant called I. horsfalliae are treated as synonyms of a variable I. lineolata, which is endemic to the island. I. saxicola Proctor is treated as var. saxicola J. R. I. Wood and Scotland of I. ternata Jacq. I. cyanantha Griseb. is treated as a synonym of I. lindenii M. Martens and Galeotti. Lectotypes are designated for I. cyanantha, I. lindenii, I. praecox, I. punctata C. Wright, I. geranioides Meisn. and I. grisebachii Urb
Past Arctic aliens have passed away, current ones may stay
Published version. Source at http://doi.org/10.1007/s10530-015-0937-9.Increased human activity and climate change are expected to increase the numbers and impact of alien species in the Arctic, but knowledge of alien species is poor in most Arctic regions. Through field investigations over the last 10 years, and review of alien vascular plant records for the high Arctic Archipelago Svalbard over the past 130 years, we explored long term trends in persistence and phenology. In total, 448 observations of 105 taxa have been recorded from 28 sites. Recent surveys at 18 of these sites revealed that alien species had disappeared at half of them. Investigations at a further 49 sites characterised by former human activity and/or current tourist landing sites did not reveal any alien species. Patterns of alien species distribution suggest that greater alien species richness is more likely to be aligned with ongoing human inhabitation than sites of transient use. The probability of an alien species being in a more advanced phenological stage increased with higher mean July temperatures. As higher mean July temperatures are positively correlated with more recent year, the latter finding suggests a clear warming effect on the increased reproductive potential of alien plants, and thus an increased potential for spread in Svalbard. Given that both human activity and temperatures are expected to increase in the future, there is need to respond in policy and action to reduce the potential for further alien species introduction and spread in the Arctic
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