Corolla remains closed at flowering, hence the name 'bottle' or 'closed gentian.' Corolla tube plicate above, the plates appearing as additional corolla lobes and alternating with the lobes proper. In this species, the plates are dilated and fimbriate at upper margin, evidently exceeding the lobes proper, and forming most of the summit of the corolla. Corolla whitish at base; the rest of it is blue.