Hygrophila sp. ‘Bold’ is a strikingly coloured Hygrophila species that appeared in aquaristics in the USA in 2006 for the first time. As it seems, this plant is not yet in cultivation in Europe.
It is not clear at the moment which species it belongs to and in which area it originates, but it could be native to Thailand. The variations of many plant species depend very much on the conditions they live in, however, Hygrophila sp. 'Bold' is among the most variable aquarium plants, with a plasticity that is simply astonishing.
It is often confused with another new plant, Hygrophila sp. 'Tiger'. Both may have a gridlike pattern on their leaves, however, submersed H. sp. 'Bold' has a slightly create leaf margin and somewhat narrower leaves. Their tip is not as obtuse as that of H. sp. 'Tiger'. Under intensive light and ample micronutrient fertilisation, H. sp. 'Bold' can assume an intensive reddish brown to purple colour, and it forms relatively short internodes. A similar effect can be observed in tanks with mineralised soil as substrate (set up according to the methods of Aaron Talbot and Tom Barr). Under "standard" conditions in the aquarium, the leaves are of a more brownish colour, and their gridlike pattern is more pronounced, the internodes grow out longer. It grows well even without CO2 injection and strong lighting, and thus H. sp. 'Bold' is a good alternative to Hygrophila polysperma, regarding adaptability as well as growth habit.
Emersed cultivation is very easy, and the plasticity of this plant is as striking in the land form. Young emersed specimens often have many glandular hairs and show a reddish brown colour, whereas older plants are distinctly less hirsute and mostly green. Other than many Hygrophila species, the flowers of H. sp. 'Bold' grow densely together with the bracts in a beautiful spike at the end of the flower stalk. The width of the emersed sprout, measured from leaf tip to leaf tip, may be up to 20 cm, so quite a bit of space ought to be reserved for this plant.
At the moment, Hygrophila sp. ‘Bold’ is not available in trade, however, it can (in the USA) quite easily be obtained by trading with other aquarists. It is easily confounded with Hygrophila sp. 'Tiger', so check the plant's identity.
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[widget=aquaticplants/hygrophila-sp-bold]Hygrophila sp. 'Bold'[/widget]