Sagittaria brevirostra Mack. & Bush

Midwestern Arrowhead


CC = 5
CW = -5
MOC = 61

© SRTurner

Family - Alismataceae

Habit - Perennial forb.

Leaves - Long petiolate to 1.5 m, petioles inflated and spongy. Blades of emergent leaves hastate or sagittate, glabrous.

Sagittaria_brevirostra_leaves.jpg Leaves.

© SRTurner

Sagittaria_brevirostra_leaf.jpg Leaf lower surface.

© SRTurner

Inflorescence - Racemes with whorled nodes. Bracts at nodes to 4.0 cm, lanceolate, with narrowly actute or acuminate tips.

Sagittaria_brevirostra_inflorescence.jpg Inflorescence.

© SRTurner

Sagittaria_brevirostra_bracts.jpg Bracts at inflorescence node.

© SRTurner

Flowers - Unisexual or perfect; those at lower nodes usually perfect. Pedicels to 25 mm, not thickened. Stamen filaments longer than anthers, not basally swollen, glabrous.

Sagittaria_brevirostra_flower3.jpg Staminate flower.

© SRTurner

Sagittaria_brevirostra_sepals.jpg Sepals.

© SRTurner

Sagittaria_brevirostra_flower.jpg Stamens.

© SRTurner

Sagittaria_brevirostra_flower2.jpg Pistillate flowers.

© SRTurner

Fruits - Globose clusters of achenes. Fruits obovate, 2.1-3.1 mm long, the beak 0.4-1.7 mm long, narrowly triangular, erect to ascending

Sagittaria_brevirostra_fruits.jpg Fruit clusters.

© SRTurner

Sagittaria_brevirostra_fruit.jpg Mature fruit cluster and achenes.

© SRTurner

Sagittaria_brevirostra_achenes.jpg Achenes, beaks ascending.

© SRTurner

Flowering - June - September.

Habitat - Mud flats, muddy margins of ponds, sloughs, and ditches.

Origin - Native to the U.S.

Lookalikes - Other species of Sagittaria, especially S. latifolia and S. calycina.

Other info. - This is a common inhabitant of areas which remain muddy and open throughout much of the growing season. There are several other members of the genus in Missouri. This one can be identified by the long, tapered bracts at the inflorescence nodes, the sagittate leaves, and the ascending beaks on the achenes.

This plant has a North American distribution similar to that of S. calycina. Both are much less widely distributed than S. latifolia.

Photographs taken near Labadie, Franklin County, MO, 7-15-2013, and at Shaw Nature Reserve, Franklin County, MO, 9-10-2017 (SRTurner).