Scientific Family
Fabaceae
Synonyms
Cassia covesii, Earleocassia covessi
Other common names
Coues' senna
desert senna
rattlebox
rattleweed
Coves' cassia
Plant type
Forbs and Subshrubs
Origin
Native
Lifecycle
Perennial
Similar species
Senna bauhinioides
Height
To about 1-1/2 feet
Riparian
No
Freely branching small shrub with woody stems and whitish to grayish hairs throughout. Leaves have several pairs of small, oval leaflets. Saucer-like yellow flowers grow in clusters from the leaf axils (between the leaf and stem) or at the stem tops.
Slightly woody base, spreading, ascending stems; leaves, stems hairy; 2 to 4 leaflet pairs per leaf; small gland on leaf stems, between lowest 2 or 3 leaflet pairs; flowers in clusters of 3 to 7, 5-petaled, yellow, in leaf axils and on terminal stem.
Habitat
Found in gravelly and sandy soils in open areas on rocky slopes, desert washes, mesas, hillsides, plains and flats.
Plant Community
Interior Chaparral
Desert Scrub
Low elevation
1000
High elevation
3000
Flower Characteristics
Each flower has 5 rounded, yellow, 1/2 inch long petals with darker veins. Clawed (narrow abruptly at the base) petals. Petals overlap at first but open fully when mature allowing the 5 reddish, hairy, leaf-like sepals below the flower to be visible.
Flower color
Yellow
Flower shape
Regular
Tubular
No
First bloom month
April
Last bloom month
October
Flower clusters
Elongated
Leaf and Stem Characteristics
Entire leaf is oblong in outline, feather-like in shape and up to 2 feet long. There are 2 to 4 (often 3) pairs of leaflets on each leaf. Oval leaflets have short stalks, are 1 to 2-3/4 inches long with rounded edges and a tiny pointed spike at the tip.
Leaf type
Compound
Leaf color
Grayish-green
Leaf shape
Round or oval
Leaf margin
Smooth
Leaves clasp
No
Leaf hairs
Leaves & stems
Spines
No
Fruit and Seed Characteristics
Fruit is dry, oblong-shaped with flat hairs, 3/4 to 2 inches long and 1/4 to 1/2 inch wide. It tapers off at the top forming a slender pointed tip 1/16 to 1/4 inch long. The ripe pod retains the seeds briefly giving it the name rattlebox or rattleweed.
Fruit type
Pod
Fruit color
Brown
Seeds are about 1/8 inch long, irregularly angled and wrinkled. Seeds remain inside the pod even after it splits open and stay there until the pod is jostled by the wind or a passing animal. This allows the seeds to spill out far from the parent plant.