A revision of the genus Ottelia (hydrocharicaea) I. Generic considerations

Strategies of reproduction, dispersion, and competition in river plants: A review

“…This phenomenon has been mentioned in Hottonia palustris (but the cleistogamic flowers of this species are merely abortive), Luronium natans, Ranunculus peltatus, Ranunculus fluitans, Ranunculus aquatilis and Ottelia (Arber 1920;Cook et al 1984;Cook 1990b;Sculthorpe 1967). In certain species such as Potamogeton pectinatus, inflorescences not reaching the surface are pollinated in bubbles surrounding single flowers, and inflorescences that could have reached the surface are aerially pollinated (Guo & Cook 1989).…”

Typification of the African endemic plant Ottelia exserta (Hydrocharitaceae)

“…Simpson (1989: 17) indicated for Ottelia exserta "Types: Mozambique, R. Shire, Kirk, & Shupanga, Kirk (both K, synt.!)". However, this statement does not designate a particular herbarium sheet as the nomenclatural type, and therefore, cannot be taken as a lectotypification, and there is no evidence that any other authors (e.g., Cook et al 1984;Symoens 2009) typified the name.…”

“…It is a dioecious perennial plant, with mature coriaceous leaves, with five nerves, petiolate, linear-elliptic to ovate, 5 -13 cm long, less than 7 cm wide, with the blades submerged when young, ultimately floating or even erect above the surface of the water. The inflorescences are unisexual, rarely on the same plant; male inflorescences with peduncle 6 -30 cm long, up to 20 or more small and yellow male flowers per spathe; female inflorescences with peduncle 16 -20 cm long, spathe narrowly ovoid, often with one female flower exserted 6 -17 cm above the spathe, sepals and petals similar to those of male; fruits ellipsoid 2.5 -4 cm long and seeds narrowly cylindric (Ridley 1886;Cook et al 1984;Simpson 1989;Hyde et al 2016). This species grows in swamps, pools, perennial or seasonal pans and in slowflowing streams, mostly in water less than 50 cm deep.…”

“…Ottelia exserta has been the subject of many studies regarding its anatomy, distribution, ecology, genetics and taxonomy (Solereder 1913;Tomlinson 1982;Cook & Urmi-König 1984;Cook et al 1984;Simpson 1989;Symoens 2009). However, from the standpoint of nomenclature, the species has not yet been typified.…”

“…(Hydrocharitaceae) contains 21 species of aquatic and freshwater plants widely distributed throughout the warmer regions of the world. It has two main centres of diversity, in tropical Africa (with a total of 13 species) and the southeastern part of Australasia (7 species), with one isolated species found in South America (Cook & Urmi-König 1984;Cook et al 1984).…”