I'll say right now that I don't often get writer's block but for something as simple as this, I am. It's really half-baked. Anything to add? I think I'm likely to revamp this entry substantially with more input. It never hurts to include the experiences of others anyway. I don't even know if 'porto velho' is really an accurate common name as those things go. 'Roraima' may be better, but I don't think we need to confuse things. A species ID should come in the next few months.
----------------------------------------------------------------
One of the most popular new foreground plants of recent years, Hygrophila sp. ‘Porto Velho’ is an attractive and versatile species that will likely remain so well into the future. Although it is more established in Japan, it is a relatively new entry into the United States, where it first appeared in specialty aquarium shops. Plants traded as Hygrophila sp. ‘Roraima’ are apparently the same thing and may be from a separate importation. The Brazilian states of Rondonia – of which Porto Velho is the capital - and Roraima are both in the western part of the country, so it may simply be two collections of a species with a range that encompasses both areas. There is even the strong possibility that it isn’t a Hygrophila at all, but a member of the closely related genus Staurogyne like the species introduced by Tropica in early 2008, highlighting the tentative nature of common names.
Regardless of its true identity, Hygrophila sp. ‘Porto Velho’ is deservedly well-liked. In all but the lowest light conditions, it grows much like familiar terrestrial ivy, making it an outstanding foreground plant. Under unobstructed light, subtle purplish accents highlight what are otherwise leaves of a uniform grayish green. Somewhat slow to acclimate, it picks up speed in time and requires occasional thinning. Selective trimming over the whole of the planting soon fills back in and is preferable to removing large chunks. By doing so, cuttings may be easily obtained.