1. A clear or yellow monobasic acid (H3PO2)
   - hypophosphorous acid, phosphorous acid

Derived forms: orthophosphorous acids

Type of: oxyacid, oxygen acid

• Tricholoma sejunctum
• Tricholoma vaccinum
• Tricholoma venenata
• Tricholomataceae
• Trichomanes
• Trichomanes boschianum
• Trichomanes reniforme
• Trichomanes speciosum
• trichome
• trichomonad
• trichomoniasis
• Trichophaga
• Trichophaga tapetzella
• Trichophyton
• Trichoptera
• trichopteran
• trichopteron
• trichopterous insect
• Trichostema
• Trichostema dichotomum
• Trichostema lanatum
• Trichostema lanceolatum
• Trichostigma
• Trichosurus
• Trichosurus vulpecula