Scientific NameSida spinosa
Other Common Names:
Synonyms (former Scientific Names):
A summer annual with yellow flowers and very small spines at the base of each leaf and branch. This weed is one of the ten most common and troublesome weeds in peanuts, cotton, and soybeans in most of the southern states.
Arranged alternately along the stem, approximately 3/4 to 2 inches (2 to 5 cm) long, and inconspicuously hairy. Leaves are oval to lanceolate in outline with toothed margins. Leaves occur on petioles that are 1/2 to 1 1/4 inches (1 to 3 cm) long and have small spines (stipules) that are 5 to 8 mm long at the base of each leaf petiole.
The seedlings with 2 heart-shaped cotyledons, and the small spines that occur at the base of each leaf petiole are both features that help in the identification of prickly sida. Velvetleaf (Abutilon theophrasti), Spurred Anoda (Anoda cristata), and Arrowleaf Sida (Sida rhombifolia) seedlings are very similar to those of prickly sida. However, prickly and arrowleaf sida have 2 heart-shaped cotyledons unlike the round and heart-shaped cotyledons of velvetleaf. Spurred anoda also has two heart-shaped cotyledons like prickly and arrowleaf sida, however the first true leaf of spurred anoda is not as coarsely toothed as that of prickly or arrowleaf sida. The cotyledons of arrowleaf sida are essentially identical to those of prickly sida, however the first true leaf of arrowleaf sida is rhombic in outline and tapers to the base unlike the first true leaf of prickly sida.
Flower Seed Head
Occur singly or in clusters on flower stalks (peduncles) that arise from the area between the stems and leaf petioles. Flowers consist of 5 orange yellow petals that are 1/8 to 1/4 inches (4 to 6 mm) long.
Fruit are capsules 1/8 to 1/4 inch (4 to 6 mm) long containing 5 individual segments each containing one seed. Each segment has 2 spikes or beak like protrusions on the tip that are pubescent. The seed are small egg shape, smooth, and dark brown,
Prickly sida is primarily a weed of agronomic crops, but can also be found in horticultural crops, landscapes, pastures, hay fields, and gardens.
upright and nonwoody
Thorns or Spines
Approximate Flower Diameter
Dominant Flower Color
shorter than leaf
Stem Cross Section
round or oval