Differences in seed morphometrics of representative orchids native to North America and Hawaii using scanning electron microscopy

• DOI: 10.1016/j.sajb.2022.11.049
• Publication Date: 2022-12-07T04:49:50Z
• Authors: Matthew H. Collier; Julianna S. Fisher; Kevin M. Gribbins; Jay A. Yoder; Lawrence W. Zettler
• Keywords: Orchidaceae; Epiphyte; Morphometrics

Ultrastructure and dimensions of whole seed, embryo, testa cells 10 orchid species native to North America Hawaii are reported. Seeds seven terrestrials (Cleistes bifaria, Isotria medeoloides, Liparis elata, L. hawaiensis, Platanthera holochila, P. integrilabia, leucophaea), two epiphytes (Encyclia tampensis, Epidendrum nocturnum), one semi-aquatic (Habenaria repens) were studied by light scanning electron microscopy. In contrast the orchid, seeds terrestrial larger in size evidenced a small length/width ratio, had greater seed volume, number cells, embryos with highest mean area, supporting existing literature. Interestingly, both Hawaiian differed noticeably from their mainland counterparts (L. hawaiensis vs. elata; holochila integrilabia leucophaea). Our study lends support for differences between genera, but also within at least genera (Liparis, Platanthera), orchids occupying different habitats separated thousands km (Hawaii, Florida). For threatened immediate extinction worldwide, better understanding morphometrics, especially structure function testa, may be useful developing more effective protocols aimed vitro germination.