海芋（学名：Alocasia macrorrhiza），，为天南星科海芋属植物，是常见观赏植物，原出东南亚及澳洲原始森林，亦见诸华南及兰屿等地，有多个俗称，如，痕芋头、狼毒（广东）、野芋头、山芋头、大根芋、大虫芋、天芋、天蒙，作为观赏植物时则称其为「滴水观音」，这是因为如果环境湿度过大，会从它阔大的叶片上往下滴水，其花是肉穗花序，外有一大型绿色佛焰苞，开展成舟型，如同观音座像。

海芋是多年生草本，叶阔大，在中国北方需在室内越冬，在南方可以露地生长，球茎和叶可以作为药用，但有剧毒，其叶汁入口会中毒。

Alocasia macrorrhizos is a species of flowering plant in the arum family, Araceae, that it is native to rainforests from Malaysia to Queensland and has long been cultivated on many Pacific islands and elsewhere in the tropics. Common names include Giant Taro and Elephant Ear Taro, while words for the plant in the various Polynesian languages include Kape (Futunan, Niuean, Tongan, Wallisian), ʻApe (Cook Islands Māori, Tahitian, Hawaiian), "ta'amu" in Samoan language, and Pulaka (Tuvalu). In Australia it is known as the "cunjevoi" (although that term also refers to a marine animal). It is edible if cooked for a long time but its sap irritates the skin due to calcium oxalate crystals, or raphides which are needle like. Alocasia species are commonly found in marketplaces in Samoa and Tonga and other parts of Polynesia. The varieties recognized in Tahiti are the Ape oa, haparu, maota, and uahea. The giant heart-shaped leaves make impromptu umbrellas in tropical downpours.