Ridsdalea backanensis A part of crown of flowering tree in natural habitat B leaves, adaxial and abaxial surface C flowering branches D flower bud and opening flower, side view E Opening flower, frontal view F, G flowers, frontal view H flowering branch showing leaves from abaxial side I flowering branch showing leaves from adaxial side J corolla, sagittal section outside and inside K peduncle, pedicels and calyxes, side view L peduncle and pedicel, side view M peduncle, pedicel, calyx and base of style, side view, corolla removed N calyx, frontal view, corolla removed O separated, upper part of calyx tube, calyx lobes, and nectary disc, frontal view P indumentum of abaxial surface of calyx on dry specimen Q portion of adaxial surface of corolla, sessile stamen and apical part of stigma R stamen S pedicel, calyx and pistil with magnified stigma, side view T apical part of stigma U middle part of stigma Photos by L. Averyanov (A, C, F–K, P) and C.H. Nguyen (B, D, E, L–O, Q–U) from plant used for preparation of the type voucher specimens (AL 1682), photo-correction and design by L. Averyanov and T. Maisak.