1. Fern of tropical America: from southern United States to West Indies and Mexico to Brazil
   - black-stemmed spleenwort, little ebony spleenwort

Type of: spleenwort

• family Alligatoridae
• family Allioniaceae
• family Aloeaceae
• family Alopiidae
• family Alstroemeriaceae
• family Amaranthaceae
• family Amaryllidaceae
• family Ambrosiaceae
• family Ambystomatidae
• family Ameiuridae
• family Amiidae
• family Ammodytidae
• family Amphioxidae
• family Amphisbaenidae
• family Amphiumidae
• family Amygdalaceae
• family Anabantidae
• family Anacardiaceae
• family Anarhichadidae
• family Anatidae
• family Ancylidae
• family Ancylostomatidae
• family Andrenidae
• family Anguidae
• family Anguillidae