Casia amarilla

Senna spectabilis, the casia amarilla or yellow shower senna, is a fast-growing deciduous tree in the Fabaceae (subfamily Caesalpinioideae) native to tropical Central and South America and now widely planted as an ornamental and naturalized through Africa, Asia, and Oceania. Plants reach 7 to 15 metres in height with a spreading crown and finely fissured grey bark. The alternate, paripinnate leaves are 15 to 40 centimetres long with 8 to 18 pairs of oblong, softly pubescent leaflets. Showy terminal panicles up to 60 centimetres long carry numerous bright yellow, slightly zygomorphic flowers with five subequal petals and seven fertile stamens of two sizes. The fruit is a long, cylindrical, blackish brown indehiscent pod 15 to 30 centimetres long, septate inside between numerous shiny brown seeds. The species is considered invasive in several tropical regions.