Grassy arrowhead

Sagittaria graminea

Also known as Grass-leaved arrowhead, Delta arrowhead

FreshwaterRosetteRunners

Grassy arrowhead (Sagittaria graminea) — Jomegat · CC BY-SA 3.0

Care at a glance

Light: Medium light
CO2: No CO₂ needed
Growth rate: Fast
Placement: Background
Type: Rosette
Temperature: 64–82°F (18–28°C)
pH: 6.5–7.8
Hardness: 3–15 dGH
Max height: 23.6 in (60 cm)
Spread: 9.8 in (25 cm)
Nutrient uptake: Root feeder
Growth region: Submersed or emersed
Difficulty: Easy
Origin: Eastern North America (Newfoundland and Ontario south to Florida, Texas, and the West Indies)
Family: Alismataceae

Overview

An undemanding rooted rosette that grows well in moderate light without CO2 and feeds mainly through the roots, so it appreciates root tabs in nutrient-poor substrate. Submerged it makes tall grassy leaves suited to the background or sides, and it spreads by runners into a thick stand that needs occasional thinning. It is native to North America and not a prohibited or federally regulated plant, though as an ornamental it has escaped cultivation in some regions.

In the wild

Sagittaria graminea is a marginal aquatic native to shallow ponds, marshes, ditches, and river edges across eastern North America, from Canada down to Florida, Texas, and the West Indies. It grows as a rooted rosette of grass-like blades and spreads along the mud by runners. In the wild it commonly grows emersed at the water's edge, sending up above-water leaves and white three-petaled flowers.

Good to know

It belongs to the water-plantain family Alismataceae, the same family as the other Sagittaria (arrowheads). Despite the genus name, this species keeps narrow strap-like submersed leaves and only develops arrow-shaped emersed foliage in some forms and conditions. Like other Sagittaria it is monoecious, carrying separate male and female flowers in whorls on the same emergent flower stalk.

Did you know

The same plant can look completely different above and below water: submerged it is a plain ribbon of grass, but when it grows out into the air it can throw arrow-shaped leaves and rings of small white flowers, a habit called heterophylly.