Polygala alba – White Milkwort

Polygala alba - White Milkwort

Polygala alba - White Milkwort (stem leaves)

Polygala alba - White Milkwort (lower leaves)

Plant Name

Scientific Name: Polygala alba

Common Name: White Milkwort

Plant Characteristics

Duration: Perennial

Growth Habit: Herb/Forb

Arizona Native Status: Native

Habitat: Upland. This wildflower grows in dry, sunny, open, grassy areas and along roadsides in oak-pinyon-juniper woodlands.

Flower Color: White to pinkish or purplish

Flowering Season: Late spring, Summer

Height: Up to 16 inches (41 cm) tall

Description: The small flowers are in long, slender, tapering, dense, spike-like racemes at the stem tips. The individual flowers have an often purplish, fringed, crested keel and 2 white, petal-like, egg-shaped lateral sepals with greenish or purplish central veins. The flowers are followed by non-winged seed capsules. The leaves are green, hairless, narrowly linear in shape, alternate on the stems, and in whorls near the base of the plant. The stems are long, erect, slender, wiry, hairless, and sparsely leafed. The plants do not produce milky sap.

The similar Winged Milkwort (Polygala hemipterocarpa) has more sparsely flowered inflorescences, winged seed capsules, and leaves that are all alternate (not whorled at the base of the plant). Broom Milkwort (Polygala scoparioides) is a broom-like plant with single-winged seed capsules and scattered leaves that are all alternate.

Classification

Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Subclass: Rosidae
Order: Polygalales
Family: Polygalaceae – Milkwort family
Genus: Polygala L. – polygala
Species: Polygala alba Nutt. – white milkwort

More About This Plant

Arizona County Distribution Map