Compass Plant

Description:

Compass plant is a long lived, perennial member of the sunflower family. Its basal leaves and stems all arise from an underground crown. A large reddish brown tap root 1 to 2 inches in diameter is located just below the crown. The tap root rapidly looses diameter as it descends up to 16 feet into the prairie soil. The large basal leaves can be 15 to 24 inches long and are deeply cut like a giant pin oak leaf. The rigid, sand paper like leaves orient themselves in a north to south direction to avoid the direct rays of the midday sun, thus leading to the plants common name, compass plant. Stems are erect and number from one to several with an overall height of from 3 to 10 feet. The simple leaves are alternately arranged on the stem and are less divided, smaller and have direct attachment higher up on the stem. Leaves are leathery and stiff with rough surfaces and hairs occurring on the leaf main veins. Large yellow flower heads from 2 to 4 inches across are conspicuous on the upper half to two thirds of the stem in small clusters. Flowering begins in late June and proceeds through August. Flower heads begin opening at the top of the stem first. There are 15 to 34 narrow yellow petal flowers (ray florets) that are 1 to 2 inches long. The center of the flower contains the numerous disk florets with yellow corollas. The fruit is a flattened achene about ½ inch long with a notched tip. Achenes develop on the outside of the head since the ray florets are the only fertile seed producing units on the flower.