木蓝（学名：Indigofera tinctoria），亦作槐蓝、马棘，豆科植物。

木蓝是向阳性植物，耐旱耐湿，极易繁殖，羽状复叶，小叶9－13枚，叶片呈羽状偏小，成熟叶片干燥后成灰蓝色，蝶形花冠，花为浅红色居多，总状花序，线状圆柱形荚果，一年可二至三获，以沉淀法制作靛蓝染料。木蓝是中国传统服饰所使用的染料。大成蓝所使用的颜色；木蓝又供药用，有泻肝散郁火、凉血解毒作用。

Indigofera tinctoria, also called true indigo, is a species of plant from the bean family that was one of the original sources of indigo dye. It has been naturalized to tropical and temperate Asia, as well as parts of Africa, but its native habitat is unknown since it has been in cultivation worldwide for many centuries. Today most dye is synthetic, but natural dye from I. tinctoria is still available, marketed as natural coloring where it is known as tarum in Indonesia and nila in Malaysia. In Iran and areas of former USSR known as basma. The plant is also widely grown as a soil-improving groundcover.