life
cycle – annual,
reproducing by seed
stems – reclining-ascending
to upright when young, sprawling habit, 4-sided, hollow, single
row of downward-facing prickles on edges, many from base, branching
growth habit
, stem
leaves – whorled
6 to 8 per node, linear to oblanceolate, sessile, bristle tip,
margins entire, rough hairs on margins and underside midrib,
hook-tipped hairs above leaves 1, leaves 2
flowers – 4-petaled,
white to greenish-white, small; axillary (above) and terminal
clusters of 2 to 5 flowers flowers
fruit – nearly
round, bristly or rough hooked hairs fruit