‘Make Hay While the Sun Shines’—The Potential for Seed Production in Rare Terrestrial Orchids Mown During the Flowering Stage

TL;DR

A rare orchid species produced seeds after being dried in a herbarium, suggesting mowed orchids can still reproduce and aiding conservation efforts.

Contribution

The study reveals that mowed orchid specimens can produce seeds without underground organs, offering new insights into orchid conservation.

Findings

Mowed orchid specimens can mature seeds using nutrients from above-ground parts.

Herbarium seeds may be used for ex situ conservation and reintroduction of endangered orchids.

Seed production in mowed areas may contribute to the northward expansion of orchid species.

Abstract

The discovery of two specimens of the rare and endemic Caucasian Lizard Orchid (Himantoglossum formosum) in 2018 in northern Azerbaijan — both found in a haystack, in the budding and early flowering stages — provided an opportunity to add these specimens to the natural history collection at the University of Debrecen. Following the standard herbarium preparation procedure (dry pressing), an unexpected event was observed: one specimen surprisingly produced a fruit and a large number of fully developed seeds. Despite the absence of tubers, the plant was able to mature its seeds. This fact suggests that mowed orchid specimens with previously pollinated flowers may be capable of maturing seeds, even in the absence of contact with underground organs (roots and tubers). Moreover, this observation may offer new insights into orchid conservation in mowed grasslands. (1) This finding could explain how some orchid species are able to persist in habitats where mowing coincides with their main flowering period (e.g., May and June in temperate Europe). (2) Our results suggest that seeds from herbarium specimens may be successfully utilised for ex situ conservation, thereby aiding in the reintroduction and reinforcement of endangered orchid populations. (3) Significant populations of orchids, including multiple Himantoglossum species, are known to inhabit mowed roadside verges. It is likely that seed production in these regularly mown areas plays a role in the northward expansion of certain species.

The discovery of two specimens of the endemic Himantoglossum formosum in Azerbaijan, both in the budding and early flowering stages, was prepared following the standard herbarium preparation procedure, an unexpected event was observed: one specimen surprisingly produced a fruit and a large number of fully developed seeds. Despite the absence of tubers, the plant was able to mature its seeds using nutrients from the above‐ground organs. This observation may offer new insights into the biology and conservation of orchids in mowed grasslands.

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