Q.The hollow, jointed stem with solid nodes, called a culm, together with a small membranous outgrowth called the ligule at the leaf-sheath junction, is characteristic of family:

Poaceae (the grass family) has a distinctive stem called a culm: cylindrical, generally hollow except at the solid nodes, with the internodes marked off clearly at each joint. Where the sheathing leaf base meets the narrow blade, a small membranous or hairy outgrowth called the ligule is typically present, preventing water and pests from entering the sheath. Liliaceae (a) is a monocot family too, but its stem is not described by the specific terms 'culm' and 'ligule', which are grass-speci …

Recognise 'culm' and 'ligule' as vocabulary specific to grasses, and match the description directly to Poaceae r …

• Picking Liliaceae simply because it is also a monocot family, without noticing that 'culm' and 'ligule' are grass-specific terms. …