Oleandra is a genus of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

s. In the

Pteridophyte Phylogeny Group The Pteridophyte Phylogeny Group, or PPG, is an informal international group of systematic botanists who collaborate to establish a consensus on the classification of pteridophytes ( lycophytes and ferns) that reflects knowledge about plant relatio ...

classification of 2016 (PPG I), it is the only genus in the family Oleandraceae, which is placed in suborder

Polypodiineae Polypodiineae is a suborder of ferns in the order Polypodiales. It is equivalent to the clade eupolypods I in earlier systems, and to the very broadly defined family Polypodiaceae in the classification of Christenhusz & Chase (2014). It probably ...

, order

Polypodiales The order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas. Description Polypodiale ...

. Alternatively, the family may be placed in a very broadly defined family

Polypodiaceae Polypodiaceae is a family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family includes around 65 genera and an estimated 1,650 species and is placed in the order Polypodiales, suborder Polypodiineae. A broade ...

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

'' as the subfamily Oleandroideae. The genus contains about 15 species. Most are erect ground ferns or scandent epiphytes that start from the ground. The lamina (leafy area of the

frond A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...

s) are simple or pinnate, and the individual pinnae are articulate to the rachis. The

sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cyc ...

are contained in discrete round sori in a single row on either side of the midrib of the fronds.

Phylogeny

The following cladogram for the suborder

(eupolypods I), based on the consensus cladogram in the

classification of 2016 (PPG I), shows a likely

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationship between Oleandraceae and the other families of the clade.

References

Polypodiales Fern genera Taxa named by Antonio José Cavanilles {{Polypodiales-stub