Parva

At about 5 cm tall, Cryptocoryne parva is the smallest known water trumpet, and that size is exactly what makes it desirable. It comes from the central highlands of Sri Lanka near Kandy, where it grows in dense colonies along riverbanks, and it is now considered rare in the wild and possibly endangered. Its few green, lance-shaped leaves form a tight rosette that reads more like a tuft of grass than a crypt.

What sets parva apart from other crypts is its appetite for light, which is greater than most, and its pace of growth: it is among the slowest plants in the hobby even when everything suits it. Soft to moderately hard water with a pH of 5 to 8 and temperatures of 23 to 26 °C keeps it healthy. CO₂ and a nutrient-rich substrate are not essential but noticeably speed it up, and keeping iron and potassium available prevents holes in the leaves.

It reproduces by lateral shoots on the rhizome and by runners, faster when kept emersed. Given time and stable conditions a handful of plants fills a small foreground patch, which is why it appears in nano tanks more than almost any other crypt.