Chengkou Houpo

Chengkou Houpo

　　Houpo (Magnolia officinalis) is a deciduous tree belonging to the genus Magnolia in the subfamily Magnolioideae of the family Magnoliaceae. It is an important medicinal and craft-use timber species native to China. Fossils of plants in this subfamily are widely distributed, with the earliest records found in the Upper Cretaceous strata of Eastern Asia, Western Europe, and North America. Fossilized spindle-shaped pollen of the Magnoliaceae family has been discovered in the Upper Lower Cretaceous layers in Yichang, the Songliao Basin, and the Jianghan Plain of China. There are about 90 species of Magnolia, distributed in Central America, North America, as well as tropical and temperate regions of Asia. Around 30 species are found in China.

　　The Houpo tree can grow up to 20 meters tall with a diameter at breast height of 35 centimeters. Its trunk is straight. The bark is grayish-brown, rough, and features longitudinal fissures, while the inner bark is purplish-brown or dark brown and smooth. Terminal buds are large, narrowly ovoid-conical, and hairless. Branches are stout and pale yellow with annular stipule scars. Leaves are clustered at branch tips, shaped inversely ovate to inversely ovate-elliptic, measuring 23–45 cm in length, with curved hairs and white powder on the underside. Flowers are solitary at branch tips, blooming simultaneously with leaves. The fruit is a cylindrical or ovoid-cylindrical aggregate, with bright red seeds and black inner skin. It is distributed across Guangxi, Hunan, Sichuan, Hubei, Guizhou, Shaanxi, Gansu, and other areas.

　　The variety M. officinalis var. biloba (concave-leaved houpo) is found in Zhejiang, Jiangxi, Fujian, Hunan, eastern Hubei, Guangxi, Anhui, and other regions, typically growing at elevations between 500 and 1500 meters. It thrives in cool, moist climates and prefers foggy areas with high humidity and ample sunlight. The average annual temperature in its distribution zone ranges from 16 to 20°C, with January averages between 3 and 9°C, and annual precipitation between 800 and 1800 mm. It favors loose, fertile, humus-rich, moist, well-drained soils with weakly acidic to neutral pH, typically mountainous sandy loam or calcareous soil derived from limestone. Wild houpo often grows mixed within deciduous broadleaf forests, flourishing in sunny spots such as valleys, riverbanks, and mountain foothills. Trees begin to bear fruit at around 15 years old, reaching full production after 20 years. Flowers bloom from April to May, and fruits ripen from late September to October. Harvested fruits are sun-dried for 1–2 days until the shells are slightly dry, then stored in sand. Before sowing, seeds are soaked in cold water for 3–5 days, the red aril is rubbed off, and then they are planted. The thousand-seed weight is approximately 310 grams, with a germination rate of 60–80%. Early spring sowing is done in rows or dots. One-year-old seedlings, 40–50 cm tall, can be transplanted or moved to nursery beds. Propagation can also be achieved through layering, cuttings, division, and grafting.

　　The bark of both Houpo and concave-leaved houpo contains magnolol, honokiol, alkaloids, volatile oils, and other compounds. With its pungent taste and warm nature, it is an important traditional Chinese medicine and has been classified as a second-class protected plant. Bark can generally be harvested 10 years after planting, but optimal harvesting occurs at 20–30 years. The roots, stem bark, buds, flower buds, and fruits can all be used medicinally and are known as Houpo or Wenpo, commonly referred to locally as "Qianpo," and are considered authentic medicinal materials in the region. The seeds have an oil content of 35% and can be pressed for oil used in soap production. The wood is lightweight with fine grain, suitable for use in drawing boards, carving, lacquerware, musical instruments, pencil shafts, and matchsticks. The tree has an elegant form, large and fragrant flowers, making it suitable as an ornamental garden plant.

　　Houpo is sporadically distributed in the mixed broadleaf forests of mountain valleys within our county, at altitudes below 1000 meters, where there is heavy fog, high relative humidity, ample sunlight, fertile and loose soil. In the 1950s, local farmers began large-scale cultivation, resulting in abundant resources.