Cleavers (Galium aparine)
This bedstraw can be very abundant in some places, as it was in this neglected hillside cemetery in Beechview, where it was blooming in early May. The stems (as you can see in the picture) are covered with prickly hairs that point toward the root, so it’s rough going if you’re a caterpillar or something trying to climb up. The leaves come in whorls of eight, or sometimes six or seven; the stems are square; and the tiny white flowers have four pointed petals.
Gray describes the genus and the species:
GALIUM L. BEDSTRAW. CLEAVERS. Calyx-teeth obsolete. Corolla wheel-shaped, valvate in the bud. Stamens 4, rarely 3, short. Styles 2. Fruit dry or fleshy, globular, twin, separating when ripe into the 2 seed-like indehiscent 1-seeded carpels. — Slender herbs, with small cymose flowers (produced in summer), square stems, and whorled leaves, the roots often containing a red coloring matter. (Name from gala, milk, which some species are used to curdle.)
G. Aparine L. (CLEAVERS, GOOSE GRASS.) Stem weak and reclining, bristle-prickly backward, hairy at the joints; leaves about 8 in a whorl, lanceolate, tapering to the base, short-pointed, rough on the margins and midrib, 2.5-7 cm. long; peduncles 1-3-flowered; flowers white; fruit bristly, 3-4 mm. in diameter. — Seashores, Que. to Fla., and in rich or shaded ground inland; perhaps sometimes introd. (Eurasia.)