Sicklepod (also known as Sickle Senna, Coffee Senna, or Wild Sensitive Plant)
Kingdom: Plantae, Division: Tracheophyta, Class: Magnoliopsida, Order: Fabales, Family: Fabaceae, Genus: Senna, Species: Senna obtusifolia · Fabaceae (Legume, Pea, or Bean family) · Pinnately compound leaf with typically 3 pairs of obovate leaflets, deciduous habit in temperate climates
Species
Senna obtusifolia
Leaf Type
Pinnately compound leaf with typically 3 pairs of obovate leaflets, deciduous habit in temperate climates
Family
Fabaceae (Legume, Pea, or Bean family)
Shape
Obovate (broader toward the apex and tapering toward the base) with rounded tips, featuring alternate leaflet pairs along the rachis
Size
Individual leaflets are approximately 1 to 2.5 inches long and 0.5 to 1.5 inches wide, with the entire compound leaf measuring around 4 to 8 inches, which is standard for mature plants
Margin
Entire (smooth and unbroken edges)
Arrangement
Alternate leaves along the main stem, with leaflets arranged in opposite pairs along the leaf rachis
Rarity
Very Common, frequently encountered as a weed in agricultural and disturbed settings across its range
Color & Pattern
Vibrant medium to bright green upper surface with a slightly paler matte green lower surface, no variegation, colors appear healthy and typical without signs of severe disease
Venation Pattern
Pinnate venation with a prominent central midrib and fine net-like lateral veins branching outward
Texture & Surface
Smooth (glabrous) to very finely puberulent surface with a papery to slightly sub-coriaceous texture
Description
Senna obtusifolia is an annual or short-lived perennial herb or subshrub growing up to 3 to 6 feet tall. It features bright yellow, five-petaled flowers, distinctive curved narrow pod fruits containing multiple seeds, and characteristic compound leaves that emit a strong, sometimes unpleasant odor when crushed.
Key Features
Pinnately compound leaves typically featuring three pairs of obovate leaflets with rounded tips, paired glands between the lowest leaflet pairs, bright yellow flowers, and distinctly curved, slender cylindrical seed pods (sickle-shaped)
Habitat
Found primarily in disturbed areas, roadsides, agricultural fields, pastures, waste places, and open woodland borders; prefers well-drained soils and full sun exposure
Geographic Range
Native to the tropics of the Americas, now widely distributed throughout tropical and subtropical regions worldwide, often naturalized as a weed in North America
Condition Notes
The specimen appears to be in Good to Excellent condition with vibrant green coloring, minimal insect or physical damage, and healthy turgidity
Interesting Facts
The roasted seeds of this plant have historically been used as a coffee substitute, hence one of its common names, coffee senna. The plant is also known to exhibit nyctinasty, where the leaves fold up at night.
Medicinal & Uses
Used in traditional medicine systems for laxative and purgative properties due to anthraquinone compounds found in the leaves and seeds. Also studied for potential antimicrobial and anti-inflammatory properties, but should be used with caution
Ecological Role
Provides nectar and pollen for various generalist pollinators and insects, though it can become an aggressive agricultural weed in pastures where unpalatability to livestock allows it to dominate
Similar Species
Coffee Senna (Senna occidentalis), which has a more unpleasant, distinct odor and more pointed leaflets, and Partridge Pea (Chamaecrista fasciculata, formerly Cassia fasciculata), which has numerous smaller leaflets
Foraging Tips
Look in disturbed soils, pastures, and along roadsides during late spring through autumn. Look for the characteristic blunt-tipped leaflets arranged in three pairs and the bright yellow blooms or curved pods
Toxicity Warning
Moderately Toxic. The leaves and seeds contain toxic compounds (such as anthraquinones and other secondary metabolites) that can cause toxicity, muscle degeneration, and dark urine in livestock if ingested in large quantities over time