红药红山茶,小乔木,嫩枝无毛。叶革质,卵状椭圆形或卵状长圆形,长5～7厘米,宽2～3.2厘米,先端尾状渐尖,基部近圆形或阔楔形,表面有光泽,背面无毛,边缘密生细锯齿,侧脉每边5～6条;叶柄长4～8毫米。花红色,单生枝顶,无柄;苞片及萼片9～11片,外轮5～6片,无毛,内轮4～5片,被灰色柔毛,阔卵形;花瓣7～8片,倒卵形,长2～2.5厘米,基部连合;雄蕊长1～1.5厘米,外轮基部合生,花丝管长3～4毫米,无毛,花药红色;子房被毛,3室,花柱长1～1.3厘米,无毛.先端3裂。蒴果近球形,直径3～3.5厘米,3爿裂开,果爿厚3～4毫米,每室有种子1～3颗。 Red medicine Hongshancha, small trees, shoots glabrous. Leaves leathery, ovate oval or ovate oblong, 5 to 7 cm long, 2 to 3.2 cm wide, apex caudate-acuminate, base nearly circular or broadly cuneate, shiny surface, abaxially glabrous, margin densely thin Serrate, lateral veins 5 to 6 on each side; petiole 4 to 8 mm. Flowers red, solitary branches, sessile; bracts and sepals 9 to 11, outer 5 to 6, glabrous, inner 4 to 5, gray pilose, broadly ovoid; petals 7 to 8, Obovate, 2 to 2.5 cm long, base united; stamens 1 to 1.5 cm long, base connate at outer ring, filaments 3 to 4 mm long, glabrous, anthers red; ovary coat, 3-locular, style long 1 ~ 1.3 Cm, glabrous. Apex 3-cleft. Capsule nearly spherical, 3 to 3.5 cm in diameter, 3 爿 split open, fruit 爿 thick 3 to 4 mm, each room has 1 to 3 seeds.