Polyploidy and gametophytic apomixis are two important and associated processes in
plants. Many hawthorn species are polyploids and can reproduce both sexually and …

We have demonstrated geographical parthenogenesis in Crataegus series Douglasianae,
an agamic complex comprising exclusively tetraploid Crataegus douglasii sensu lato and …

Range and niche expansion are commonly associated with transitions to asexuality,
polyploidy and hybridity (allopolyploidy) in plants. The ability of asexual polyploids to …

Black-fruited hawthorns in North America comprise two taxonomic groups within the genus
Crataegus, section Brevispinae and section Douglasianae. The first of these has recently …

Background Hawthorn species (Crataegus L.; Rosaceae tribe Maleae) form a well-defined
clade comprising five subgeneric groups readily distinguished using either molecular or …

The impacts of ploidy level changes on plant physiology and ecology present interesting
avenues of research, and many questions remain unanswered. Here, we examine the …

• Premise of the study: Amelanchier polyploid apomicts differ from sexual diploids in their
more complex diversification, greater species problems, and geographic distribution. To …

Abstract Background and Aims The taxonomic complexity of Crataegus (hawthorn;
Rosaceae, Maleae), especially in North America, has been attributed by some to …

Hawthorns and medlars are closely related genera in Rosaceae subfamily Maloideae,
whose taxonomy remains poorly understood. Gametophytic apomixis occurs in polyploids …

Differences in the numbers of stamens and styles per flower are conspicuous features of
variation in North American hawthorns (Crataegus L.). Variation in stamen number between …