Eleocharis parvulus (acicularis) T/C CUP

Eleocharis parvulus (acicularis) T/C CUP refers to a tissue culture cup of dwarf hairgrass, one of the most popular carpeting plants used in freshwater aquascaping. The naming on the label highlights a very common point of confusion in the aquarium trade, as Eleocharis parvula (or parvulus) and Eleocharis acicularis are actually two distinct species with different growth habits.

Species Clarification: Parvula vs. Acicularis

When a cup is cross-labeled this way, it typically contains one of two options depending on the nursery or distributor:

Attribute	Eleocharis acicularis (Dwarf Hairgrass)	Eleocharis parvula / pusilla (Mini Hairgrass)
Typical Height	10–15 cm (4–6 inches)	3–5 cm (1–2 inches)
Growth Habit	Strictly upright, straight needle-like blades	Slightly curled or spiraled, horizontal and low-creeping
Aquascape Placement	Foreground to midground transition	True foreground lawn or nano-tanks
Light Tolerance	Higher tolerance for variable lighting	Demands consistent medium-to-high light to stay low

What Does T/C CUP Mean?

"T/C" stands for Tissue Culture. These plants are propagated in sterile laboratory environments using a nutrient-rich agar gel or liquid medium.

100% Sterile: They are guaranteed to be free of pests, snails, duckweed, algae, and pathogens.
High Yield: A single cup contains dozens of tiny individual plantlets compressed together, offering significantly more coverage than a traditional lead-bunched or potted plant.

Planting & Care Requirements

To successfully transition a tissue culture cup into your aquarium, follow these core parameters:

Preparation: Remove the plant mass from the cup and gently rinse away the clear nutrient gel or liquid media under lukewarm tap water. Use sharp aquascaping scissors to divide the dense mass into 6 to 8 smaller plugs.
Planting: Use fine tweezers to insert each plug deep into the substrate (ideally a nutrient-rich aquarium soil), leaving just the tips poking out. Space them about 1 inch apart in a grid pattern so their horizontal runners can bridge the gaps to form a carpet.
Lighting: Medium to high lighting is required. If the light is too low, the hairgrass will stretch vertically or fail to spread horizontally.
CO2 & Nutrients: While technically optional for some hardier strains, CO2 injection and regular liquid fertilization are highly recommended to achieve a thick, vibrant green lawn and prevent algae from taking over the slow-growing initial plugs.