Any of numerous flowerless , seedless vascular plants having roots , stems , and fronds and reproducing by spores .
蕨,蕨类植物数量较大的有根、茎以及复叶的无花、无子管状植物,通过孢子再生。
Flowerless vegetable that usually lives in aquatic environments ; it produces oxygen and is at the base of the food chain .
隐花的菜那在水生环境里通常居住;它生产氧气并且在食物链的基地。
Used only in former classifications : comprising what is now considered a heterogeneous assemblage of flowerless and seedless organisms : algae ; bacteria ; fungi ; lichens .