Dahuolu Huang, also known as Leitou Guolu Huang, is the whole herb of Primula cernua, a perennial or biennial plant in the Primulaceae family. It is collected in the summer. So, what are the effects and functions of Dahuolu Huang?
According to traditional Chinese medicine, Dahuolu Huang has the effects of dispelling wind, clearing heat, and detoxifying. It is used for wind-heat cough, sore throat, and hot toxic sores and boils.
Dahuolu Huang is found in broad-leaved forests, valleys, and roadsides at an altitude of 600-2600m. It is distributed in Jiangxi, Zhejiang, Hubei, Hunan, Guangxi, Guizhou, Sichuan, Yunnan, and other regions.
Dahuolu Huang is a perennial or biennial herb. The stem is usually clustered, zigzag or erect, 10-30cm tall. In moist habitats, the lower part of the stem often creeps, roots at the nodes, and the upper part bends and rises, reaching up to 60cm in length. It may have a single stem or multiple branches, densely covered with long multicellular hairs measuring 1-1.5mm.
The leaves are opposite; the petioles are 2-12 times shorter than the leaf blade, covered with soft hairs. The uppermost two pairs of leaves on the stem are closely spaced, forming a whorl, often 1-2 times larger than the lower leaves. The leaf blades are ovate to elliptic-ovate, 1.5-8cm long, 8-40mm wide. The apex is acute or slightly blunt with a sudden pointed tip, and the base is wide-wedge-shaped. Both sides of the leaf are covered with rough hairs with visible veins on the lower side.
The inflorescence is terminal, near cymose, with multiple flowers. The pedicels are 1-7mm long, covered with soft hairs. The calyx is split almost to the base, with lanceolate lobes, and covered with soft hairs on the back. The corolla is yellow, 10-13mm long, with a fused base of about 3mm, and 5 lobes at the apex, which are inverted-ovate with transparent glandular spots. There are 5 stamens, with the filaments fused at the base to form a tube, and the upper part separated. The anthers are ovoid-lanceolate with ciliate margins. The pistil is up to 8mm long, with the lower part and the apex of the ovary covered in hairs. The capsule is brown, with a diameter of 3.5-4mm. It blooms from May to June and fruits from August to September.
Dahuolu Huang: "Dispels wind, clears heat, and transforms phlegm. Used to treat wind-heat sore throat, cough, blood in the stool, falling and bloating sensation, hard and painful abdomen, hot toxic sores, and other symptoms." (From "Commonly Used Medicinal Herbs in Sichuan")
