Stachyanthus Engl.

Rio, Cédric Del, Stull, Gregory W. & Franceschi, Dario De, 2020, Survey of the fruits and endocarps of Icacinaceae (Lamiids, Icacinales), European Journal of Taxonomy 645, pp. 1-130 : 106-108

Genus Stachyanthus Engl.

Fig. 34

Description

FRUIT. Elliptical, acute-acuminate at the apex, laterally compressed, yellow or blue when mature. Epicarp strigose to pubescent, with simple hairs with granular ornamentation and / or uncinate hairs, rugose-ridged or smooth when dry. Calyx persistent.

ENDOCARP. Cream to brown, elliptical in lateral view, lenticular in transverse section. Keel surrounding the endocarp in the plane of symmetry. Apex asymmetrical; base symmetrical. Outer surface of the endocarp pitted and ridged. Pits more or less circular, associated with bullate tubercles. Ridges forming a diffuse pattern, faintly apparent. Vasculature of the endocarp free. Primary vascular bundle positioned outside the endocarp wall. Endocarp wall with at least one layer with rows of periclinally oriented cells. Locule surface smooth and lacunate.

Fig. 34. (see full caption on page 106)

Key to the genus Stachyanthus

1. Endocarp ca 22 mm in length, ridges sharp ............................................................... S. zenkeri Engl.

– Endocarp ± 17 mm in length, ridges rounded ................................................................................... 2

2. Endocarp length ca 17 mm, pits per face 150–160 ............................ S. donisii (Boutique) Boutique

– Endocarp length ca 11 mm, pits more than 180 ............ S. occidentalis (Keay & É.Miège) Boutique

Figures

Fig. 34. Fruits of Icacinaceae Miers. 1–9. Stachyanthus donisii (Boutique) Boutique (J.H. Laurent 423). 1. Dried fruit, lateral view. 2–6. Endocarp. 2. Lateral view showing the pits and ridges. 3. Dorsal view showing the keel. 4. Opposite lateral view. 5. Apical view. 6. Basal view. 7. SEM image of the bullate tubercle from the locule side. 8. SEM image of the endocarp in transverse section, showing arrangement of the bullate tubercle cells. 9. Detail showing the central tubercle cells. – 10–18. Stachyanthus occidentalis (Keay & É. Miège) Boutique (A. Chevalier 23794). 10. Dried fruit, lateral view. 11–15. Endocarp. 11. Lateral view showing the pits and ridges. 12. Dorsal view showing the keel. 13. Opposite lateral view. 14. Apical view. 15. Basal view. 16. SEM image of the bullate tubercles from the locule side. 17. SEM image of the pericarp in transverse section showing bullate tubercles. 18. Detail of the endocarp wall. – 19–27. Stachyanthus zenkeri Engl. (Carvalho 3626). 19. Dried fruit, lateral view. 20–24. Broken endocarp. 20. Lateral view showing the pits and ridges. 21. Dorsal view showing the keel. 22. Opposite lateral view. 23. Apical view. 24. Basal view. 25. SEM image in transverse section of the pericarp showing the ridges and bullate tubercles. 26. Detail on the pericarp in transverse section. 27. Detail showing the endocarp wall. Images taken from Del Rio (2018). Scale bars: 1–6, 10–15, 19–24 = 10 mm; 25 = 2 mm; 26 = 1 mm; 8, 17, 27 = 500 μm; 7 = 300 μm; 16, 18 = 200 μm; 9 = 50 μm.