Introduction
The Osmunda cinnamomea, also known as the cinnamon fern, is a plant species in the Osmundaceae family. It can grow up to 2 meters tall and is found in the southeastern part of Yunnan Province, China, at elevations of 1200-1500 meters.
Morphological Features
The plant can grow up to 2 meters tall. It has a creeping rhizome that is about 1 centimeter thick and woody. The fronds have a petiole that is about 1 meter long and 4 millimeters thick. The base of the petiole is chestnut brown and becomes dark straw-colored towards the top. The fronds are pinnately divided and deeply lobed. The pinnae are alternate, slanting upwards, and have no stalk. The lower pinnae are spaced about 11 centimeters apart and are sickle-shaped, about 40 centimeters long and 15 centimeters wide at the base. The tips of the fronds are elongated and the base is strongly inclined, with both sides being highly asymmetrical. The upper side of the rachis is undivided, with only one wing about 1 centimeter wide. The upper 1/4-1/3 of the lower side is also undivided, while the middle and lower parts are sparsely divided into 6-8 gradually shorter segments. The segments are linear-lanceolate, about 13 centimeters long and 1.8 centimeters wide, with a gap of up to 2 centimeters between them. The tips are gradually pointed, and the lower side extends downward, not reaching or barely reaching the next pair of segments. The infertile margin has serrations. The secondary veins are visible on both sides of the fronds, spreading out sparsely and dividing once or twice. When the fronds dry, they become herbaceous, dark green, and hairless. The rachis and the main axis of the fronds are straw-colored with longitudinal grooves, and there are sparse spines along the grooves on the upper side of the rachis.
Ecological Habits
The cinnamon fern is endemic to the southeastern part of Yunnan Province, China (Malipo County).
It grows in the understory of mixed forests at elevations of 1200-1500 meters.
