Popcorn Cassia (Senna didymobotrya): Peanut Butter Scented Shrub

Popcorn Cassia, also called Peanut Butter Cassia, is a delightful tropical shrub that engages multiple senses—its leaves emit a distinct peanut butter aroma when crushed, and its flower buds resemble popcorn kernels before opening to bright yellow blooms. Native to eastern Africa, Senna didymobotrya (family Caesalpiniaceae) brings whimsy and fragrance to warm-climate gardens.

Sensory Appeal

The pinnately compound leaves have 8-18 pairs of oval leaflets. When brushed or crushed, they release a strong, unmistakable peanut butter scent. The flower buds are rounded, yellow-green, and clustered—strikingly like popcorn. They open to bright yellow, five-petaled flowers, 1-1.5 inches wide, in upright racemes. The plant grows 6-15 feet tall as a multi-stemmed shrub, blooming heavily in warm months.

Taxonomic Classification

Culture and Uses

Popcorn Cassia thrives in full sun, well-drained soil, and heat. It's drought-tolerant once established but flowers best with regular water. It's not frost-hardy (damage below 30°F), so in cooler zones it's grown as an annual, container plant, or greenhouse specimen. It can be cut back hard in spring to rejuvenate.

The peanut butter scent is a hit in children's gardens and sensory gardens. The flowers attract bees and butterflies. In its native range, it's used as a cover crop and green manure. It's relatively pest-free but can self-seed aggressively in ideal conditions. For a similar sensory experience in cooler climates, consider the herb Melissa officinalis (Lemon Balm) or Agastache species (Anise Hyssop) which have fragrant foliage.