Awl-leaf arrowhead

Description

Sagittaria subulata is native to eastern USA and South America, where it thrives in both freshwater and brackish environments, often forming vast meadows in estuaries. This popular aquarium plant is widely cultivated by major nurseries and frequently traded under its scientific name or as Sagittaria pusilla, although the latter may be mislabeled. S. subulata requires moderate light and can tolerate hard alkaline water, growing well without CO2 injection but benefiting from it. A nutrient-rich substrate or water with high concentrations of nitrate, phosphate, potassium, iron, and trace elements promotes robust growth. This plant is susceptible to iron deficiencies, which manifest as yellowing leaves. Dense planting can result in leaves reaching up to 60 cm in length, while less dense groups may produce shorter stems (5-10 cm). S. subulata spreads quickly by runners and can form a dense carpet over time. It produces long flower stalks that float on the water surface, bearing tiny white flowers. Under favorable conditions, it can grow floating leaves with elliptical blades. The emersed growth habit is low, with leaf rosettes spreading wide and spatulate leaves. There are several varieties of S. subulata, including one previously sold as Sagittaria natans. This hardy plant can remain outdoors over winter in Central Europe and forms many flower stalks and floating leaves with reddish-brown spots in shallow ponds. In the aquarium, it produces long submerged leaves that turn brownish-green to reddish-brown under intense light. Due to its relatively low height, S. subulata makes an excellent fore-, mid-, or background plant, offering a grasslike texture that can be used to accentuate other species and create natural-looking arrangements.