Acanthus montanus (Mountain Thistle)

Native to western and central tropical Africa, extending south to Angola and Zambia and east to Rwanda and Burundi, this sparsely branched shrub has woody stems and commonly reaches about 6 feet tall. It grows in forests, including riverine forest in Zambia. Its deeply lobed leaves end in sharp spines, and upright flower spikes have conspicuously spiny bracts and sepals. The flowers are white with pale pink veins and a broad, spreading lower lip. It has naturalized in Mauritius. In the Mount Cameroon region, its leaves are used traditionally for coughs and fever. Photographed in Bogotá, Colombia.