Spotted St. John's wort

Description

Hypericum punctatum, the spotted St. John's wort, is a perennial herb native to North America. The yellow-flowered herb occurs throughout eastern North America into southern Canada. The process of microsporogenesis carried out by this plant is prone to errors in chromosomal segregation. It has a diploid number of 14 or 16. Insects are attracted to the plant's pollen and the hypericin in the plant's leaves is toxic to mammals. The species is commonly called spotted St. John's wort because of the dark spots on its petals that distinguish it from other species of Hypericum. St. John's wort refers to the species of this genus as a whole. H. punctatum is referred to as punktiertes Johanniskraut in German. The specific epithet punctatum is Latin, meaning "dotted", referring to the many black dots on the leaves and flowers. Hypericum punctatum is seldom branched and grows to 50–100 cm (20–39 in) in height. Each of the one to several reddish, spotted stems are woody, especially near their base, and are terete. Old stems typically persist through subsequent seasons. The stems arise from a curved or twisted root crown. The root system consists of a branching taproot and several short rhizomes from which vegetative colonies of the herb can grow. The leaves of the herb are 2–6 cm (0.79–2.36 in) long and are situated opposite on the glabrous stem, either sessile or with very short petioles. The leaves vary in shape from oblong to elliptic or ovate, have rounded points at their apex, and taper towards their base. The inflorescence is composed of a corymbiform cluster of terminal cymes crowded with many yellow flowers that measure 0.8–1.5 cm (0.31–0.59 in) in width. The flowers are star-like in shape and have five petals. The sepals and petals are spotted with dark dots, especially on their underside, with the petals about twice as long as the oblong and acute sepals. The petals are dichotomously veined and have black bands between the veins. Each flower has twenty stamens or more. These numerous stamens are situated in three principal bundles and vary in filament length. Both the stamens and filaments are yellows, though filaments can occasionally become purple with age. In the center of the flower a flask-like pistil is surrounded by many yellow anthers. The anthers are about 0.5 mm (0.020 in) in diameter and have divergent yellow thecae and purplish black connective. The sessile, ovate pistil in 1.3–4 mm (0.051–0.157 in) long and has three carpels and three locules.