Galium aparine L.

Cleavers, Bedstraw


CC = 0
CW = 3
MOC = 77

© SRTurner

Family - Rubiaceae

Habit - Annual forb.

Stems - Spreading to weakly ascending or clambering, to 100 cm, often multiple from base and few-to several-branched, 4-angled, hollow, roughened with minute, prickly, retrorse hairs on and sometimes also between the angles, otherwise glabrous or only sparsely pubescent with short hairs.

Galium_aparine_stem.jpg Stem and node.

© SRTurner

Leaves - Whorled, sessile, usually 6-8 per node, generally spreading or somewhat ascending in orientation. Leaf blades 8-60 mm long, 1-5 mm wide, narrowly oblanceolate, short-tapered to a sharply pointed tip, the midvein usually extended into a short, sharp point, angled or tapered at the base, not glandular on the undersurface, with only the midvein visible, the margins and underside midrib with minute, retrorse, prickly hairs, the margin usually somewhat curved under.

Galium_aparine_whorl.jpg Leaf whorl.

© SRTurner

Galium_aparine_leaves1.jpg Leaves adaxial.

© SRTurner

Galium_aparine_leaves2.jpg Leaves abaxial.

© SRTurner

Inflorescence - Axillary clusters or occasionally solitary flowers, occurring mostly at nodes above the stem midpoint, positioned over the leaves. Flowers relatively few, the stalks absent or to 1 mm long at flowering, becoming elongated to as much as 8 mm at fruiting.

Galium_aparine_inflorescence.jpg Inflorescence.

© SRTurner

Galium_aparine_inflorescence2.jpg Flowering node.

© SRTurner

Flowers - Corollas 1.0-1.2 mm long, 4-lobed, white, the tube to 0.5 mm long. Stamens 4, included, alternating with lobes. Styles 2, included, pale yellow. Stigmas capitate, pale-yellow. Ovary 2-carpellate. Calyx globose, hispid, 2 mm in diameter.

Fruits - Biglobose schizocarps 2-3 mm long, 3.5-5.5 mm wide, the surface densely pubescent with hooked hairs 0.5-0.8 mm long.

Galium_aparine_flowers.jpg Flowers and fruit.

© SRTurner

Galium_aparine_fruits.jpg Immature fruits.

© SRTurner

Flowering - April - July.

Habitat - Forests, streambanks, pond margins, prairies, marshes, sloughs, pastures, ditches, gardens, lawns, railroads, roadsides, and disturbed areas.

Origin - Native to the U.S. and Eurasia.

Lookalikes - Other species of Galium.

Other info. - Just about everyone has encountered this plant at one time or another. It occurs throughout Missouri and is common in most places, and is likewise ubiquitous across the entire continental U.S. It is easily recognized by its weak and sprawling stems which cling ("cleave") to clothing, and which bear whorls of (usually) 6 narrow leaves. Species of Galium can be a little challenging to distinguish from each other. Important characters to note are the number of leaves at each whorl, whether the tiny fruits are hairy or not (hairy in this case), and the color and number of corolla lobes (4 white, in this case).

The hooked prickles on the fruits enable them to hitch a ride, Velcro-fashion, on the fur and clothing of passing animals and humans. Steyermark mentioned that the fruits, if dried and slightly roasted, could be brewed into a coffee-like beverage superior to most other North American coffee substitutes. He advised collecting the fruits by allowing them to adhere to clothing, then scraping them into a collection receptacle. Native Americans used the plant medicinally for renal, urinary, and dermatological problems, including poison ivy rash, and also as an antihemorrhagic, diuretic, and love potion. Masses of the plant stems have been used as a sieve to filter milk. The young plants are edible, but distasteful unless cooked due to the stem prickles.

There has been some dispute about the nativity status of the plant in inland regions of North America, with some researchers suggesting that inland populations arose from contaminated crop seeds of early settlers. The plant can be a pest weed in crop fields, though its impact is usually relatively minor.

The species name aparine is derived from an ancient Greek word meaning "clinging" or "seizing." Numerous other common names for the plant (e.g., "catchweed," "stickyweed," "sticky willy") usually refer in some way to this property.

Photographs taken near Labadie, Franklin County, MO, 4-21-2020, 5-2-2020, and 5-8-2020 (SRTurner).