Ability of Limnocharis flava to escape from episodic submersion by rapid elongation of its leaf petiole

Fira Juliani, Erizal Sodikin, Benyamin Lakitan

Abstract: Limnocharis flava commonly known as yellow velvetleaf plant is a promising vegetable for cultivation at riparian wetlands. However, this plant is also considered as noxious weed at paddy field during rice growing season. Socio-economically, this plant cannot compete with rice; therefore, cultivation of velvetleaf plant should be done during rice off-season, i.e. at early rainy season, with risk of total submersion if depth of floodwater is beyond expected level. Objective of this research was to investigate probable morphological adaptation of the velvetleaf plant to episodic submersion. Plants with relatively uniform height were submerged for 3, 6, 9, and 12 consecutive days in an outdoor experimental pool. Untreated plants were used as control. After submersion, all treated plants were allowed to recover for 7 days. Results of this study indicated that velvetleaf plant was able to escape from submersion condition by rapid elongation of their petioles; consequently, increased its height. It took less than two days for at least one leaf blade per plant had raised above water surface. The plant survived as long as at least one leaf had escaped out of water. However, number and size of leaves reduced during submersion. Chlorophyll concentration index (CCI) increased for compensating smaller leaf area. Long but weak petioles developed during submersion were immediately collapsed as soon as submersion treatments were terminated, failed to support weight of leaf blade. Velvetleaf plants gradually developed new normal leaves during recovery period.

Keywords: aquatic plants; morphological adaptation; wetland vegetable; yellow velvetleaf

Date published: 2019-04-15