This is probably the best suited Aponogeton species for the aquarium. It generally does not require a rest period like most species, is quite hardy, and propagates vegetatively--the only species to do so. Inflorescence are produced, but instead of flowers, plantlets develop from the nodes, similar to Echinodorus plants; these can be separated in about 2-6 weeks once the tuber and leaves are formed, though they frequently separate on their own. The tubers can be planted in the substrate to form new plants. The second photo above illustrates the inflorescence with plantlets.
The tuber is up to 2.5cm/1 inch in length; the medium-green ribbon-like leaves grow up to 35cm/14 inches long and have undulate margins. Floating leaves are rare but when produced can be up to 90cm/35 inches in total length.
The name Aponogeton stachyosporus assigned by de Wit is considered by a few authors to refer to this species, but it is actually a smaller version of A. undulatus having narrower leaves.
The genus is endemic to the Old World and species occur in tropical and sub-tropical regions in Africa, Madagascar, India & SE Asia and Australia. Most of the popular aquarium plants are native to India and SE Asia. They readily flower in the aquarium, producing long inflorescence that extend above the surface where the flowers are borne. Seed production in the aquarium is very rare.
Most species have a rest period, coinciding with the dry season in Africa and with temperature differences and water level changes for Asian species. Previous literature recommended removal of the tuber and dry storage for all species, but this will in fact kill the plant. Proper handling of the tuber during the rest period will be indicated for the respective species.
Ideal position in aquarium
Suitable for the sides and rear walls especially in groups, or specimen plants mid-ground. In shorter tanks the leaves will partially float on the surface.
Moderate with balanced nutrients; in higher light supplemental CO2 and additional fertilization will be essential.
Growth rate: Slow
Minimum Tank Suggestion: 20 gallon tall.
Ideal water parameters for Undulate Aponogeton: Soft to medium hard (< 15 dGH), acidic to slightly basic (pH below 8) water, temperature 22-28C/71-83F.