desert false indigo

not listed

N5 - Secure

SNR - Unranked

not listed

FACW - Facultative wetland

FACW - Facultative wetland

FACW - Facultative wetland

Desert false indigo is a 3′ to 10′ tall, erect, bushy, perennial shrub that rises on 1 to several stems. It reproduces by suckers and sometimes forms dense thickets. It is often found leaning over water.

The stems are erect or leaning, often branched, woody, and up to 2⅜″ in diameter at the base. The bark is gray and rough and has numerous short, horizontal lenticels.

First-year twigs are grayish-brown and are covered with short, fine, white, appressed hairs. Second-year twigs are usually hairless.

The leaves are alternate, deciduous, and 12″ to 40″ long. They are pinnately divided into usually 9 to 21, occasionally up to 35 or more, leaflets. They are on ⅝″ to 1⅜″ long leaf stalks. The leaf stalks are usually covered with short, white, appressed hairs, sometimes hairless.

The leaflets are oblong to elliptical, 1″ to 1¾″ long, and ⅜″ to ¾″ wide. They are tapered at the base and rounded or blunt at the tip. The leaf tip is occasionally slightly notched and has a short, sharp, abrupt point. The upper surface is dark green, not shiny, and is hairless or sparsely covered with minute hairs. The lower surface is pale green and is usually sparsely covered with fine, short, hairs. The underside is also sometimes dotted with black, sunken glands. The margins are untoothed.

The inflorescence is a cluster of 1 to 4, usually 3, erect, spike-like racemes at the end of the stem and branches. The racemes are densely flowered, 2″ to 6″ long, and ⅜″ to ¾″ wide.

The individual flowers are on 1 ⁄32″ to 1 ⁄16″ long stalks. There are 5 green sepals fused for most of their length into a bell-shaped, ⅛″ long tube (calyx), then separated into 5 shallow, unequal, triangular lobes. The upper 4 lobes are short, the lowest lobe longer and narrower. The corolla is a single 3 ⁄16″ to ¼″ long, deep violet-purple petal. The petal is tubular near the base, unfolded near the tip to form a protective covering over the stamens and pistil. There are 10 stamens with purple filaments united near the base and yellow to orange anthers protruding well beyond the corolla.

The fruit is a bright green, hairless, conspicuously glandular, oblong, ¼″ to ⅜″ long pod with 1 or 2 seeds. The pod matures mid August to late September. It turns brown when it dries.

3′ to 10′

Deep violet-purple

Lake shores, riverbanks, stream banks, meadows, shallow marshes.

Late May to early July

Sources

2, 3, 4, 5, 7, 8, 24, 28, 29, 30.

Native

Common

Plant

Inflorescence

Leaves

Infructescence

Location: Lake Shore, MN

Location: Hole-in-the-Mountain Prairie