Lagenandra

Lagenandra is a genus of aquatic (to semi-aquatic) flowering plants in the aroid family, Araceae,^[2] endemic to the Indian Subcontinent (Bangladesh, India and Sri Lanka).^[3][4] The genus has gradually become more known through the aquascaping and aquarium hobby, in which several related Araceae genera are already highly prized and grown on a large scale (notably Anubias, Bucephalandra and Cryptocoryne); Lagenandra, however, is still relatively rare in cultivation or private collections.

Lagenandra
Lagenandra ovata (left) and Lagenandra koenigii (right)[1]
Lagenandra toxicaria, in Kerala, South India.
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Alismatales
Family:	Araceae
Subfamily:	Aroideae
Tribe:	Cryptocoryneae
Genus:	Lagenandra Dalzell

The genus is visually-similar to (and, in places, sympatric with) the Cryptocoryne, but is distinguishable for its involute vernation (leaf growth); comparatively, Cryptocoryne tends to exhibit convolute vernation.^[5]

Description

Helophytes, rarely rheophytes, with thick creeping rhizome; leaf blade simple, ovate to almost linear, fine venation transverse-reticulate; spathe tube with connate margins; spadix entirely enclosed in spathe tube; flowers unisexual, perigone absent. Differs from Cryptocoryne in having female flowers spirally arranged (pseudo-whorl in Lagenandra nairii, whorled in Lagenandra gomezii) and free; spathe tube "kettle" with connate margins (containing spadix) occupying entire spathe tube; spathe blade usually opening only slightly by a straight or twisted slit; berries free, opening from base; leaf ptyxis involute.^[6]

Species

Accepted species are as follows.^[3] A key to the species described before 1986 was provided by Crusio and de Graaf.^[7]

1. Lagenandra bogneri de Wit - Sri Lanka
2. Lagenandra dewitii Crusio & de Graaf - Sri Lanka
3. Lagenandra erosa de Wit - Sri Lanka
4. Lagenandra gomezii (Schott) Bogner & Jacobsen - Bangladesh
5. Lagenandra jacobseni de Wit - Sri Lanka
6. Lagenandra keralensis Sivadasan & Jaleel - Kerala
7. Lagenandra koenigii (Schott) Thwaites - Sri Lanka
8. Lagenandra lancifolia (Schott) Thwaites - Sri Lanka
9. Lagenandra meeboldii (Engler) C.E.C. Fischer - southwestern India
10. Lagenandra nairii Ramamurthy & Rajan - southwestern India
11. Lagenandra ovata (L.) Thwaites - southwestern India, Sri Lanka
12. Lagenandra praetermissa de Wit & Nicolson - Sri Lanka
13. Lagenandra thwaitesii Engler - Sri Lanka
14. Lagenandra toxicaria Dalzell - southwestern India
15. Lagenandra undulata Sastry - Assam