水松（学名：Glyptostrobus pensilis）为柏科植物。水松主要在中国生长，少数分布在越南与老挝，为水松属唯一一种，是孑遗植物。

半落叶乔木，高8至10米，最高可达25米，枝稀疏；有屈膝状呼吸根；小枝有一年生和多年生两型，一年生的到冬季和叶子同脱落；叶子互生，在苗枝上的呈针形或线形，老枝上的呈鳞形；雌雄同株，雄球花有15至20个螺旋状排列的雄蕊，雄蕊通常有5至7个花药；雌球花卵球形，有15至20枚有两个胚珠的珠鳞。

Glyptostrobus pensilis, also known as Chinese swamp cypress, is the sole living species in the genus Glyptostrobus. It is native to subtropical southeastern China, from Fujian west to southeast Yunnan, and also very locally in northern Vietnam.

It is a medium-sized to large tree, reaching 30 m (98 ft) tall and with a trunk diameter of up to 1 m (3.3 ft), possibly more. The leaves are deciduous, spirally arranged but twisted at the base to lie in two horizontal ranks, 5–20 mm (0.20–0.79 in) long and 1–2 mm (0.039–0.079 in) broad, but 2–3 mm (0.079–0.118 in) long and scale-like on shoots in the upper crown. The cones are green maturing yellow-brown, pear-shaped, 2–3 cm (0.79–1.18 in) long and 1–1.5 cm (0.39–0.59 in) diameter, broadest near the apex. They open when mature to release the small, 5–20 mm (0.20–0.79 in) long, winged seeds.