The Lapeirousia jacquinii flower tubes vary between reddish to bluish purple, some are even pale blue at certain stages on the same plant. All of them are long. Most of these corolla tubes are also straight, curvature in the tube apparently arriving with age, shortly before withering and decay.
The tubes are from about 3 cm to 4 cm long. They are faintly longitudinally lined (Manning, 2007; Manning and Goldblatt, 1997; iNaturalist).