Virginia Tech Weed Identification Guide

Arrowleaf Sida: Sida rhombifolia

arrowsida3-12b.jpg (88613 bytes) Weed Description:  A summer annual with yellow
flowers and very small spines at the base of each leaf and branch. This plant most often occurs as a weed of peanuts, cotton, and soybeans in the southeastern United States from Virginia south to Florida and Texas.
Seedlings:   Both cotyledons are generally
heart-shaped with a small indentation at the cotyledon apexes. The first true leaves are widest above the middle and tapering toward the leaf base (rhombic in outline).

Leaves:  Arranged alternately along the stem, approximately 3/4 to inches long, with petioles that are less than 1/3 the length of the leaves.  Leaves are widest at or above the middle and taper toward the leaf bases (rhombic).  The upper 1/2 of the leaves have toothed or serrated margins while the remainder of the leaves are untoothed.  Petioles have small spines (stipules) that occur at their bases.

arrowsida3-19.jpg (122165 bytes)
sidrh3-19.jpg (62664 bytes) Fruit: A capsule.

Flowers:  Occur singly on flower stalks (peduncles) that arise from the area between the stems and leaf petioles.  Flowers consist of 5 yellow petals that are 4 to 8 mm long.

Stems:   Erect, branched, reaching as much as 3 1/3 feet in height.  Stems are covered with hairs and also have short spines (stipules) at the base of each leaf petiole.

Roots:  A taproot.

asida5-15.jpg (64658 bytes)
Identifying Characteristics:   The seedlings with 2 heart-shaped cotyledons, the small spines that occur at the base of each leaf petiole, and the 'rhombic' leaves are all characteristics that help in the identification of arrowleaf sida.  Velvetleaf (Abutilon thophrasti), Spurred Anoda (Anoda cristata), and Prickly Sida (Sida spinosa) seedlings are very similar to those of arrowleaf sida.  However, arrowleaf and prickly sida have 2 heart-shaped cotyledons unlike the round and heart-shaped cotyledons of velvetleaf.  Spurred anoda also has two heart-shaped cotyledons like arrowleaf and prickly sida, however the first true leaf of spurred anoda is not as coarsely toothed as that of arrowleaf or prickly 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.