谷精草科（拉丁语：Eriocaulaceae）包括10属约1,150-1,200种，分布在热带和亚热带地区，也有部分种类生长在温带地区，以美洲种类最多。中国只有1属约40种，分布在除西北外的全国各地，以南方最多。

本科植物多为多年生草本，也有部分为一年生，叶狭窄，丛生；小花，单性，辐射对称，雄花和雌花混生，风媒；果实为膜质蒴果。喜湿，一般生长在水分充足的土壤中，有部分种类为水草。

1981年的克朗奎斯特分类法单独分出一个单科谷精草目，1998年根据基因亲缘关系分类的APG 分类法将本科列入禾本目。

The Eriocaulaceae are a family of monocotyledonous flowering plants in the order Poales, commonly known as the pipewort family. The family is large, with about 1,150-1,200 species described in 10 genera. They are widely distributed, with the centers of diversity for the group occurring in tropical regions, particularly the Americas. Very few species extend to temperate regions, with only 16 species in the United States, mostly in the southern states from California to Florida, only two species in Canada, and only one species (Eriocaulon aquaticum) in Europe. They tend to be associated with wet soils, many growing in shallow water. This is also reported from the southern part of India and the regions of Western Ghats hot spots.