Crossleaf milkwort, is a small but showy herbaceous annual native to eastern North America. Considered rare and endangered in the state of Pennsylvania, Polygala cruciata is known for being a unique wildflower due to its distinctive floral structure and leaf arrangement.

This intriguing plant is less than 12 inches tall, with tiny flowers packed into barrel-shaped heads at the tips of stems or short branches. These heads measure about ½–2½ inches long and under ¾ inch thick. Each flower bears two large wing-like inner sepals, three small outer sepals, and three petals fused into a central tube. The blossoms, ranging from deep pink to greenish, are only 2–4 mm long.

Leaves occur in whorls of three or four along the square, hairless stem. They are dark green, linear to elliptic, entire, and sessile, measuring about 1–3 inches long.

Though crossleaf milkwort bears a distinctive floral design, it is easily overlooked because of its small stature and rarity. Flowering from July to September, it sets seed in autumn when the capsules split to release two blackish-brown oval seeds. These may fall by gravity or be carried by water, and ants are thought to aid dispersal, drawn to the fleshy appendage on each seed. The compact flower heads provide nectar mainly for small native bees, including sweat bees and solitary bees, contributing to pollinator diversity. Deer and rabbits may browse occasionally, but the plant’s small size and low nutritional value make it generally avoided — a trait that helps ensure its survival.

Crossleaf milkwort prefers full sun to partial shade in bogs, wet meadows, and swampy openings, rooting best in acidic, sandy or peaty soils. It is usually found in wetlands, though occasional records occur in moist non-wetland sites. In Pennsylvania, it has been documented in southeastern and southwestern counties.

Crossleaf milkwort is threatened by competition from aggressive plants, habitat disturbance, and especially wetland drainage, and could benefit from restoration efforts. It remains a subtle yet beautiful component of Pennsylvania’s wetland flora.