Soft Lithospermum is a perennial herb of Boraginaceae, soft Lithospermum. Having hard or soft fur. The roots contain purple substances. The stem is erect or spread out, with a height of up to 25 centimeters. The leaves are alternate, and the basal leaves are covered in needle shaped or elongated strips. The flower flocs are sickle shaped cymes, nearly spherical, and densely covered with many flowers; Bracts strip lanceolate or elongated, shorter than flowers; The corolla is purple, the tube is nearly as long as the calyx, the base is annular, the eaves are bell shaped, the throat is without appendages, and the small nut is ovoid with warty protrusions.
Rhebia euchroma (Royle) Johnst is a traditional Chinese medicinal herb and belongs to the second class protected plant in China. This species exhibits a typical dimorphic style phenomenon.
Soft purple grass is a perennial herb with a phenomenon of heterostyly, and its population consists of plants with two flower types: long and short styles. The frequency of the two plants occurring in the population is close to 1:1; The phenological period is significantly influenced by altitude. Low altitude populations and higher altitude populations have early germination, initial flowering, peak flowering, and final flowering, with a long duration of flowering. However, the fruit ripening and withering periods are later at higher altitudes.
Soft purple grass has the typical characteristics of heterostylic plants: the stigma and stamens of long and short style flowers have a vertical height interaction correspondence, and there is no overlap in spatial position; The anthers of short styles are larger than those of long styles, but the stigma is significantly shorter than that of long styles, with significant differences between them; The pollen of both flower types is dumbbell shaped, polar circular, and constricted in the middle. The single flower pollen of long style flowers is greater than that of short style flowers, but the pollen is significantly smaller than that of short style flowers.
The flowering period of the population can last for about 30 days; Most flowers open from 8:00 to 12:00 in the morning, and when they bloom, the anthers crack and the color of the corolla gradually changes from deep purple to pink. The single flowering period is about 6-7 days, and the stigma is receptive throughout the entire single flowering period.
Soft purple grass is mainly distributed in Tibet and Xinjiang; It is also found in western Asia. Born on gravel slopes, grasslands, and meadows at an altitude of 2500-4200m. China is distributed in Xinjiang and western Tibet. Distributed outside of China in northwestern India, Nepal, Pakistan, Kashmir, Afghanistan, Iran, Central Asia in Russia, and Siberia.