Black Jack: A Weed with a Wide Distribution

Introduction

Bidens pilosa, also known as black jack, is an erect perennial herb that can grow up to 20-150 cm tall. It is globally distributed across tropical and subtropical regions and is one of the 230 to 240 known species of the genus Bidens.

Native Range and Distribution

The native range of B. pilosa extends across the tropical and subtropical regions of the world. It is commonly found in disturbed areas, such as roadsides, fields, and gardens.

Characteristics and Significance

B. pilosa is an opportunistic weed that can rapidly colonize disturbed areas. It produces numerous small, yellow flowers and has a distinctive, slightly hairy stem. The plant is often considered a nuisance, but it also has medicinal properties and is used in traditional medicine in some cultures.