delta arrowhead
(Sagittaria platyphylla (Engelm.) J.G. Sm.)

Overview

Appearance

Sagittaria platyphylla is an aquatic plant in the Water-Plantain family that can grow up to 5 ft. (150 cm) tall. It has stolons and fleshy corms. S. platyphylla is native to much of the eastern, central and southern United States, Mexico and Panama.

Foliage

S. platyphylla has two types of leaves. One type of leaf is held above the surface by long rigid triangular petioles. These leaves are linear-ovate to ovate are from 2-6.5 in. (4.6-16.4 cm) long with an acute apex. The submerged leaf is sessile and strap shaped.

Flowers

The flowers are held on a raceme in 3-9 whorls. Each flower has three green sepals and three white to pinkish petals.

Fruit

Fruits are from 0.3-0.5 in. (0.7-1.2 cm) in diameter. S. platyphylla spreads both by seed and vegetatively via corms.

Ecological Threat

S. platyphylla can be found in many shallow water habitats where it can form dense colonies that restrict water flow, increase sedimentation and lead to flooding. It also displaces native vegetation in regions where it is nonnative. S. platyphylla prefers still or slowly moving waters.

Maps

Invasive Listing Sources

• Oregon Noxious Weeds

References