Hygrophila Species – Which is which?

Posted by on Jan 23, 2010 in All Categories, Plant Profiles | 0 comments

Hygrophila Species – Which is which?

The Genus Hygrophila (Family Acanthaceae) includes some of the oldest and most suitable species of aquarium plants. When I founded Extraplant, it was my goal to supply a wide range of aquarium plants to the aquascaping enthusiast. Rare and new plants as well as the “bread and butter” species are now part of the choice at Extraplant. It has happened to me many times that the Hygrophila species I bought at the shop turned out to be something completely different when growing submerged. Both the appearance of the emerged plant and, very often, the name on the tag had suggested otherwise.

Especially the narrow-leaved Hygrophilas often leave you guessing until after a couple of weeks, submerged growth shows their real identity. In order to protect my customers from buying the wrong species of plants, I have set up a tank where I keep all plants I offer at my online shop. I keep them for at least three months growing in ceramic pots and, of course, submerged. This allows me to state the correct names and, cultural requirements.

Several Hygrophila

Several Hygrophila

Hygrophila salicifolia and Hygrophila corymbosa var. ‘Angustifolia’

The first two species I will compare are Hygrophila salicifolia and Hygrophila corymbosa var. ‘Angustifolia’. These are the first two pots in the photo above. You can use the following criteria to distinguish between the two:

H. corymbosa var. ‘Angustifolia’:

  • Narrow leaves but up to 15 mm wide, so clearly broader than those of H. salicilolia. Length 60-100 mm. No hairs.
  • Stem round, 2-3 mm thick near the tips. Dark green or brown. No hairs.

H. salicifolia:

  • Narrow leaves, 3-6 mm wide, 60-100cm long, no hairs.
  • Stem square, tips up to 4mm thick, green, no hairs.

The photo compares both species:

H. angustifolia, H. salicilolia

H. angustifolia, H. salicilolia

We also have other species of Hygrophila corymbosa at Extraplant, some of which I have cultivated over the past months so that I can now be certain as to which is which.

The two pots on the right in the image at the top of this post are two subspecies with different leaf colouration and -shapes. The right one is the popular and widely available “Nominal form” of H. corymbosa.

Hygrophila corymbosa

Its leaves will remain mostly green, even under strong lighting. The opposite leaves are closely spaced and growth is steady under almost all conditions.

Hygrophila corymbosa

Hygrophila corymbosa

Hygrophila corymbosa “Red Lucanas”

This name is not a proper name but a trade name. The plants are imported from Tenerife, from the “Las Lucanas” nursery. This plant is most likely identical with H. corymbosa var. ‘Glabra’. It’s popular name is “Cherry Leaf”. It is a wonderful, striking plant which I can recommend especially for larger aquaria as a background species.

Hygrophila corymbosa "Red Lucanas"

Hygrophila corymbosa "Red Lucanas"

Hygrophila corymbosa var. stricta “Blue”

This is also a trade name, referring to the light blue flowers. As a matter of fact, you will frquently notice blue flowers in freshly imported specimens. Under water, this is a relatively small-leaved variety, similar to H. corymbosa ‘Siamensis’ but with reddish leaves and dark green to brown-red leaf veins. Leaves also tend to be a bit wider than those of the “Siamensis”. This species is slightly more demanding when growing submerged than the aforementioned. Growth is also slower.

Hygrophila stricta "Blue"

Hygrophila stricta "Blue"

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