Fig. 6

Jaltomata umbellata tubular flower development. a Stage A: Sepal development occurs asymmetrically, with the first sepal initiating on the abaxial side. b Stage B: Once all sepal primordia have expanded, organs become fused at the base to form a tube. c, d Stages C: Removal of partially fused sepals reveals the initiation of petal and stamen primordia in an asymmetric progression. e, f Stages C–D: Separate petal primordia elongate without fusion. g–i Stages E–H: As stamens continue to mature, petals of ~ 1–2.6 mm diameter flowers become increasingly fused above the stamen attachment point to form a corolla tube. By stage H (i), petals are longer than sepals. Scale bars = 100 μm, and bud diameter also provided in bottom right corner. s, sepal; p, petal; st, stamen; tri, trichome; fus, corolla fusion; fil, anther filament; g, gynoecium; sty, style