Fig 1.
Bayesian 50% majority-rule consensus tree under partitioned models (cpDNA data: matK, ndhF, psbA-trnH, rbcL, trnL-F and ycf1; 63 taxa).
Numbers at the nodes indicate Bayesian posterior probabilities and maximum parsimony bootstrap values (> 50%), in that order. Thick lines indicating the clades in which glands or specialized pollinator reward tissues have evolved.
Fig 2.
Flower and fruit morphology of Alphonsea glandulosa.
A, Branch, showing leaf-opposed inflorescence position, and lanceolate leaves. B, Abaxial view of the inflorescence, showing 5–6 carpels per flower. C, Adaxial view of the inflorescence, showing pubescent pedicels with one densely pubescent medial bract (arrowed). D, Fruit with subglobose monocarps. E, Single monocarp, dissected to show seed arrangement.—Photos: A–E, Yun-hong Tan.
Fig 3.
Morphology of the surface of the inner petal glands, stamen, carpel and pollen of Alphonsea glandulosa (scanning electron micrographs).
A, Surface of the glandular tissue, showing the nectary stomata (arrowed). B, Close-up of the nectary stomata. C, Stamen. D, Carpel, dissected to show biseriate ovules. E, Pollen grain. F, Rugulate pollen exine ornamentation.
Fig 4.
Glandular tissue, nectar and flower visitors of Alphonsea glandulosa.
A, Nectar at pistillate phase. B, Nectar at the end of staminate phase. C, Morphology of the glandular tissue after FAA fixation. D, Morphology of the glandular tissue after rehydration from dried specimens. E, Small curculionid beetles observed visiting the flowers. F, Bee observed visiting the flower.—Photos: A, C, F, Yun-Yun Shao; B, D, E, Bine Xue.
Fig 5.
Anatomical structure of the inner petal glands and adjacent non-glandular part of the inner petals (paraffin sections).
A, Section of the inner petal nectary gland, showing the nectary epidermis (E), secretory parenchyma (SP), ground parenchyma (GP), and vascular tissue (V). B, Section of the non-glandular part of the inner petals, showing the epidermis (E), parenchyma (P) and vascular tissue (V).
Table 1.
The occurrence of inner petal glands and specialized pollinator reward tissues in genera, tribes and subfamilies across the family Annonaceae.
Fig 6.
A, Flowering branch. B–D, Flower (B, Lower view. C, Lateral view. D, Top view, showing six carpels and three rows of stamens). E–F, Outer petal (E, Abaxial view. F, Adaxial view). G–H, Inner petal (G, Abaxial view. H, Adaxial view, with nectar glands at the base). I, Flower with petals removed, showing the attachment of stamens and carpels. J–K, Stamen (J, Adaxial view. K, Abaxial view). L. Carpel, longitudinal section, showing ovule arrangement. M, Fruit, composed of separate monocarps. N, Single monocarp. O, Longitudinal section of monocarp, showing seed arrangement. Drawn by Yun-xiao Liu.
Fig 7.
Distribution of Alphonsea glandulosa.