Complex sentence: The flower spikes are 6 to 10 cm in length and about 4 to 7 cm in diameter; they appear in November and December (late spring to early summer) in the species native range.
Split into simpler sentences: The flower spikes are 6 to 10 cm in length and about 4 to 7 cm in diameter. These appear in November and December (late spring to early summer) in the species native range.