morphological character
great burdock
Biennial herb, with thick fleshy straight roots, up to 15 cm, up to 2 cm in diameter, with branched roots. The stem is erect, 2 meters high, stout, with a base diameter of 2 cm, usually purplish red or light purplish red, with many high ribs and oblique branches. Most of the stems and branches are covered with sparse short papillae hairs and long spider silk hairs mixed with small brown glandular spots. Basal leaves are ovate in width, up to 30 cm long and up to 2 1 cm wide, with sparse shallow concave teeth or tips, heart-shaped at the base, petiole up to 32 cm long, with different colors on both sides, green on the top, sparse short coarse hairs and yellow glandular spots, gray or light green on the bottom, sparse by thin fluff or fluff, yellow glandular spots, gray petiole, dense spider-like fluff and yellow glandular spots. Cauline leaves are isomorphic or nearly isomorphic to basal leaves, with equal and equal indumentum, and the leaves at the lower part of inflorescence are small, and the base is truncated or shallow heart-shaped.
Most or a few heads are arranged in loose corymbs or conical corymbs at the top of stems and branches, and the peduncle is stout. Involucre ovoid or ovoid, with a diameter of 1.5-2 cm. The involucral bracts are multi-layered, mostly, the outer layer is triangular or lanceolate, about 1 mm wide, and the middle layer is lanceolate or linear, with a width of 1.5-3 mm; All bracts are nearly equal in length, about 1.5 cm long, and there are cartilaginous barbs at the top. The floret is purplish red, the corolla is 1.4 cm long, the tubule is 8 mm long, the eaves are 6 mm long, there are no glandular spots outside, and the corolla lobes are about 2 mm long.
Achene obovate or oblique obovate, 5-7 mm long and 2-3 mm wide, compressed on both sides, light brown, with many veinlets, with or without dark brown spots. The crown hair is multilayer and light brown; The crown hair is just rough, unequal in length, up to 3.8 mm long, and the base is not connected with a synthetic ring, which is scattered and falls off. The flowering and fruiting period is from June to September.