X. macrocephala Vahl, Enum. PI. 2: 204. 1805.
X. laxifolia Martins, Flora 24 (Beibl. 2) : 58. 1841.
X. laxifolia a major Martins, Flora 24 (Beibl. 2) : 58. 1841.
X. sellowiana Kunth, Enum. PI. 4: 13. 1843.
Type. Brazil, Martius Hb. Fl. Bras. 547 (M, F photo 18669).
Plants of var. major, as the name suggests, are merely qualitatively large ecologic or genetic expressions of the species, in which the leaves and scapes are longer and coarser, and the spikes conspicuously larger, reaching 35 mm in length and 20 mm in diameter. N o satisfactory "break" point can be reached in separating the two varieties.