Morphological characteristics and quarantine significance of Bidens pilosa

Hairy beggarticks (Bidens pilosa) is a dangerous quarantine weed that infests crops of absolutely all agricultural plants. It also actively occupies any uncultivated land with a disturbed phytocenosis. This species is currently absent in the territory of Russia, but the risks of its introduction remain extremely high.

The wide geography of its distribution confirms the high harmfulness of this object:

• America;
• Africa;
• Asia;
• Australia;
• Europe (foci identified in Spain and Portugal).

Morphological features of achenes

The pest's achenes are narrow, linear, with a characteristic pappus. Located on the straight apex are 2-6 prickly awn-like hairs, which are covered with downward-pointing tooth-like bristles. The surface of the fruit is longitudinally ribbed, rough, and covered with sparse warts with upward-pointing bristles. The obliquely truncate base of the achene is surrounded by a contrasting light-colored rim, and the rounded hilum is noticeably depressed. The color of the fruits is dark gray, almost black, lighter at the base and apex; the hairs and bristles are yellow, and the warts have a light brown hue.