Triangular in cross section.‘the seeds are trigonous’
- ‘Seeds are extremely small, being less than 1 mm in size, with a wide variety of shapes (ellipsoid, oblongoid, ovoid, globose, trigonous or tetragonous).’
- ‘One is African and supported by trigonous ovary in transverse section.’
- ‘In superior view the fruits are markedly trigonous with three obtuse angles.’
- ‘Hermaphrodite flowers; ovary 3-3.5 cm. long, 1-1.5 cm. wide, rather acutely trigonous or 4-sided according to position.’
Early 19th century: from Greek trigōnos (see trigon).