Detailed Explanation of the Biological Characteristics and Growth Habits of Licorice
1. Biological characteristics
(1) Flower size and seed characteristics. Due to different habitats, licorice naturally forms three ecotypes, namely sandy-land licorice, ridge-land licorice and floodplain licorice. The flowers of different licorice ecotypes are similar in size, but the seeds differ markedly in size, in the order floodplain licorice > ridge-land licorice > sandy-land licorice; the hard seed rate is ridge-land licorice > sandy-land licorice > floodplain licorice. Licorice grown from seed generally flowers and sets seed after 3 years.
(2) Distribution characteristics of roots and rhizomes. Sandy-land licorice has well-developed horizontal and vertical rhizomes, grows evenly, and its horizontal rhizomes extend over a wide range in an irregular radial pattern, with many branch plants, forming a large underground network composed of varying numbers of lateral roots around the mother plant; commercial licorice consists mainly of rhizomes. Ridge-land licorice has poorly developed and few rhizomes, few branch plants, and a small extension range; its main root is well developed but uneven, generally thick at the top and thin at the bottom, with the root head 20-30 cm from the ground surface; commercial licorice consists mainly of the main root. Floodplain licorice has many thick and sturdy horizontal rhizomes that extend over a large range, with many branch plants; its main root is extremely poorly developed and mostly forked; commercial licorice consists mainly of rhizomes.
2. Growth habits
Licorice mostly grows in plains, mountainous areas or river valleys of low-altitude regions in the northern temperate zone. Wild licorice companion plants include bluish dogbane, sand sagebrush, Chinese iris and ephedra. The soil is mostly sandy soil, and neutral or slightly alkaline pH is preferable. Licorice has the characteristics of light preference, drought tolerance, heat tolerance, salt-alkali tolerance and cold tolerance. It often shows regional distribution and has a relatively wide ecological range. In China it can grow both in the severely cold **Altay and in the hot Turpan.