Hygrophila
Encyclopedia
Hygrophila, commonly known as the temple plants or hygros, is a genus of flowering plants in the family Acanthaceae
. There are about 125 species, of which about 40 are aquatic. The genus has a pan-tropical distribution, with some members entering sub-tropical areas. It is one of only two genera in its family that contains aquatic plants, the other being Justicia
. The genus is treated inside the tribe Hygrophileae, which is noted as being in need of revision at the genus level, meaning the current taxonomic boundaries of Hygrophila are likely to change in the future.
are either homomorphic (i.e. all having one form) or heteromorphic (i.e. different leaves having different forms). When they are homomorphic, they are always simple and entire. When heteromorphic, the basal or submerged leaves are pinnate
ly divided with either filiform (i.e. feather-like) or linear segments that can be either simple or forked, while the cauline leaves (i.e. those on the stem) or emergent leaves are entire.
The flower
s have petals ranging from white to purple in colour, having either 5 equal lobes or 2 lips. When an upper lip is present, it is erect and concave with either 2 lobes or 2 teeth, while the lower lip has 3 lobes. 4 stamen
s are present with 2 sometimes being staminodal
(i.e. non pollen producing). They are not exerted and are fused to the petal tube above the middle. The individual filaments are united into pairs by a membrane at their bases, while the anthers have 2 locule
s. The anther sacs have no spurs or tails and are at the same level and parallel. A nectariferous disc is present but inconspicuous. Pollen
grains are 3- or rarely 4-colporate, meaning the aperture
s are composed of both a colpus and a porus. Each flower produces 6 to many seeds.
trade, including H. difformis
(water wisteria) and Hygrophila polysperma
(Indian swampweed). Many members of the genus are troublesome weeds in irrigation and drainage ditches as well as rice fields. Several have become established outside of their native ranges, largely due to the aquarium trade, such as H. polysperma
in the southern United States
.
Acanthaceae
The family Acanthaceae is a taxon of dicotyledonous flowering plants containing almost 250 genera and about 2500 species....
. There are about 125 species, of which about 40 are aquatic. The genus has a pan-tropical distribution, with some members entering sub-tropical areas. It is one of only two genera in its family that contains aquatic plants, the other being Justicia
Justicia
Justicia is a genus of flowering plants in the bear's breeches family, Acanthaceae. The roughly 420 species it contains are native to tropical to warm temperate regions of the Americas, with two species occurring north into cooler temperate regions...
. The genus is treated inside the tribe Hygrophileae, which is noted as being in need of revision at the genus level, meaning the current taxonomic boundaries of Hygrophila are likely to change in the future.
Description
The leavesLeaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are either homomorphic (i.e. all having one form) or heteromorphic (i.e. different leaves having different forms). When they are homomorphic, they are always simple and entire. When heteromorphic, the basal or submerged leaves are pinnate
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
ly divided with either filiform (i.e. feather-like) or linear segments that can be either simple or forked, while the cauline leaves (i.e. those on the stem) or emergent leaves are entire.
The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s have petals ranging from white to purple in colour, having either 5 equal lobes or 2 lips. When an upper lip is present, it is erect and concave with either 2 lobes or 2 teeth, while the lower lip has 3 lobes. 4 stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s are present with 2 sometimes being staminodal
Staminode
In botany, a staminode is an often rudimentary, sterile or abortive stamen. This means that it does not produce pollen. Staminodes are frequently inconspicuous and stamen-like, usually occurring at the inner whorl of the flower, but are also sometimes long enough to protrude from the...
(i.e. non pollen producing). They are not exerted and are fused to the petal tube above the middle. The individual filaments are united into pairs by a membrane at their bases, while the anthers have 2 locule
Locule
A locule is a small cavity or compartment within an organ or part of an organism ....
s. The anther sacs have no spurs or tails and are at the same level and parallel. A nectariferous disc is present but inconspicuous. Pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
grains are 3- or rarely 4-colporate, meaning the aperture
Aperture (botany)
Apertures are very small spots on the walls of a pollen, where the wall is thinner and/or softer. For germination it is necessary that the pollen tube can reach out from the inner of the pollen and transport the chromosomes to the egg deep down in the pistil...
s are composed of both a colpus and a porus. Each flower produces 6 to many seeds.
Ecology and uses
A number of species are cultivated for the aquariumAquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
trade, including H. difformis
Hygrophila difformis
Hygrophila difformis, commonly known as water wisteria , is an aquatic plant in the acanthus family. It is found in marshy habitats on the Indian subcontinent in Bangladesh, Bhutan, India and Nepal...
(water wisteria) and Hygrophila polysperma
Hygrophila polysperma
Hygrophila polysperma, commonly known as dwarf hygrophila, dwarf hygro, Miramar weed or Indian waterweed, is an aquatic plant in the acanthus family. It is native to India and Malaysia, and has also been introduced to the US states of Florida, Texas and possibly Virginia...
(Indian swampweed). Many members of the genus are troublesome weeds in irrigation and drainage ditches as well as rice fields. Several have become established outside of their native ranges, largely due to the aquarium trade, such as H. polysperma
Hygrophila polysperma
Hygrophila polysperma, commonly known as dwarf hygrophila, dwarf hygro, Miramar weed or Indian waterweed, is an aquatic plant in the acanthus family. It is native to India and Malaysia, and has also been introduced to the US states of Florida, Texas and possibly Virginia...
in the southern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Species
- Hygrophila pogonocalyx – da an sui suo yi in Chinese . It's endemic to TaiwanTaiwanTaiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
.