Broad Leaf vs. Grassy Weeds

Broadleaf Characteristics

• Broadleaf weeds have one main vein in the middle of the leaf with smaller veins branching out. The leaves are a variety of shapes, sizes, arrangements and edges. Some broadleaf weeds grow prostrate to the ground and some species are upright. Stems are both rounded and square shaped; and creeping broadleaf weeds may spread by stolen or rhizomes. Seedlings are commonly identified by a pair of seed leaves (cotyledon) followed by the growth of true leaves. Flowers develop as either a single blossom on the weed stem or as flower clusters. Broadleaf weeds have a fibrous root system consisting of a large primary taproot or a network of thin roots, or a combination of both.

Common Broadleaf Weeds

• Dandelion (Taraxacum officinale) is a perennial weed with coarsely lobed leaves in a rosette pattern and bright yellow flowers. The flowers first appear as a white globe that blows away easily in the wind. It is sometimes called blow-ball or lion’s tooth. It spreads by seed drop and segment generation from its long taproot. Prostrate spurge (Euphorbia supine) is an annual broadleaf weed with long stems, white flowers and opposite forming leave structure. It is similar in look to prostrate knotweed (Polygonum aviculare), which is also a summer annual that spreads by seed drop in the fall. Both curly dock (Rumex crispus) and blunt-leafdock (Rumex obtusifolius) have long, oval-shaped, rosette-formed leaves; and flowers that change from green to reddish.

Grassy Characteristics

• The long narrow leaves of grassy weeds have parallel veins and a visible joint system. Joints –nodes-- are where the leaves attach themselves to the main stalk. The stalks are usually hollow except at the nodes. Grassy weeds grow in bunches or spread by rhizome or stolen. New leaves grow from the ground or a stem and are rolled or folded from a center spiral in the bud. The creeping, spreading habit of grassy weeds is created by an underground or above ground system of specialized stems that send out roots. The root system develops into a fibrous mass of tiny branches. The flower system of grassy weeds develops on one long stem, called a spikelet. Flowers are branched from the spikelet with one or many flowers.

Common Grassy Weeds

• Barnyardgrass (Echinochloa crus-galli), sometimes known as watergrass or summergrass, is a common bunch-type annual that spreads by seed from green to purplish seedheads. Smooth crabgrass (Digitaria ischaemum) is also a bunch-type weed that spreads by seed, but its seedhead is purple. Millet (Setaria faberi) is considered a grassy weed when not under cultivation. It grows several feet in height, is a summer annual and spreads by seed from a large greenish seedhead.