Staurogyne repens: grower data, planting and its Rio Cristalino origin

What the grower data says

Tropica’s rating table puts Staurogyne repens at easy, with low light, low CO2 and medium growth, and a height of 3–10 cm or more ^[1]. Aquasabi agrees on easy and medium growth and lists no need for added CO2, but rates light medium ^[3].

Tropica’s own article on the plant asks for more than its rating table does. It says Staurogyne repens “prefers medium to high light and supplement of CO2”, and that it needs fertilizing: a nutrient-rich substrate plus micronutrients in the water to keep the fresh green color and steady, covering growth ^[2]. The plant page itself notes that at low light growth is more upright and far fewer side shoots form ^[1]. Read together, the ratings describe what the plant tolerates; the article describes what gives the low, carpet-like form most people buy it for.

Origin and relatives

Tropica received the plant from an aquarist in 2005 and later visited its habitat, where it grew on rocks in the Rio Cristalino in Mato Grosso, in the southern Amazon ^[2]. Tropica’s article says DNA analyses show it is closely related to Hygrophila, which also occurs in South America, but under water it differs clearly: smaller leaves, stiff brownish stems, slower growth and a compact, bushy habit ^[2].

Placement and planting

Aquasabi lists it for the foreground, middle ground and nano tanks ^[3]; Tropica’s article calls it suitable for the foreground and middle ground ^[2]. Tropica’s planting method is specific:

1. Cut off the longest upright shoots.
2. Divide each pot into two to four pieces and plant them close together in a small group.
3. Remove the emersed-grown leaves, which will die off under water anyway ^[2].

New horizontal, creeping shoots then form from the base and spread over the substrate ^{[1, 2]}. The leaf die-off after planting is a normal transition from nursery to tank; see why new plants melt.

Growth and trimming

Growth is slow compared with Hygrophila ^[2]. If the upright shoots were removed at planting, Tropica says it may be months before more trimming is needed; after that, new vertical shoots can be removed weekly to keep the low form ^[2]. Tropica produces it from tissue culture and also recommends it for nano tanks because of its slow, creeping growth and hardy nature ^[2].

Names and taxonomy

Staurogyne repens (Nees) Kuntze is accepted in the World Checklist of Vascular Plants, in the acanthus family Acanthaceae, with Ebermaiera repens Nees as its original name ^[4]. WCVP’s native range is northern and west-central Brazil and Guyana ^{[4, 5]}. Mato Grosso, where Tropica found it, lies in the region WCVP calls west-central Brazil.