Content deleted Content added
m →Uses: copy edit |
m →Phylogeny and evolution: copy edit |
||
Line 51:
}}
}}
''Pereskia'' ''s.l.'' divided into two main clades. Clade A, the Northern clade, comprised species mainly found in and around the [[Caribbean|Caribbean basin]]. Clade B comprised species found mainly in South America, either in the [[Andes]] (the Andean clade) or futher south (the southern South American or SSA clade). Subsequent studies confirmed
The two main clades of ''Pereskia'' ''s.l.'' differ in their geographical distribution: with one exception, Clade A, the Northern clade, is found around the [[Gulf of Mexico]] and the [[Caribbean Sea]] whereas Clade B occurs south of the [[Amazon basin]]. Species of Clade A always lack two key features of the stem present in most of the remaining "caulocacti": like most non-cacti, their stems begin to form [[Bark (botany)|bark]] early in the plant's life, and they also lack [[stoma]]ta – structures which control the admission of air into a plant and hence control [[photosynthesis]]. By contrast, species of Clade B typically delay forming bark and have stomata on their stems, thus giving the stem the potential to become a major organ for photosynthesis.<ref name=EdwaNyffDono05/><ref name=AsaiMiya16/> The subclades of Clade B, the Andean and SSA clades, also show consistent differences. The SSA clade is distinctly tree-like with pink flowers, and bears its leaves on short, densely crowded branchlets (brachyblasts). The Andean clade consists of climbers or undershrubs with smaller flowers, and has spines rather than leaves on brachyblasts.<ref name=AsaiMiya16/>
| |||