Perianth segments and stamens 5; perianth tube basal surface with 5 radial ribs, or segments not proximally connate; plants subglabrous or only pubescent.

• 花被片和雄蕊5；花被筒基部表面具5辐射状肋，或者裂片下部不合生；植株只近无毛或短柔毛。(2