When is the best time to harvest Gastrodia elata seed capsules?

After the Gastrodia elata flower is pollinated, the ovary gradually enlarges, and the capsule is light brown or pink, elongated ovoid, with 6 longitudinal ridges. Each capsule contains 10,000 to 50,000 seeds, up to a maximum of 80,000 seeds. The seeds are tiny. They are powdery, and their size and shape are difficult to distinguish with the naked eye. Under a microscope, mature seeds are spindle-shaped, 0.6 to 1 mm long and 0.14 to 0.2 mm wide. The embryo is 170 to 180 micrometers long. The seed coat is white and translucent, wing-like, composed of thin-walled cells, with no endosperm inside; the embryo is light brown or dark brown, and those without dark brown color are immature seeds, called empty seeds. The cross section and longitudinal section of mature Gastrodia elata seeds appear elliptical and circular, respectively, under a microscope.

Gastrodia elata generally takes 21 to 30 days from stem emergence to flowering, and 27 to 35 days from flowering to fully mature fruit. If seeds from naturally split capsules are stored too long, the seed germination rate decreases significantly, so do not wait until the capsule splits naturally to collect seeds. It is more suitable to collect seeds when the capsule skin surface is glossy, the longitudinal grooves are not obviously sunken, and the capsule feels slightly soft when pinched. At this time the skin is about to split but has not yet split; after peeling the skin, most seeds have already loosened and are easy to shake out, and the seeds are cream-colored. Such seeds have a germination rate more than 60% higher than seeds from naturally split capsules. Therefore, when cracks are found in the lower ridge lines of the capsule, it can be cut off and the seeds shaken out promptly for sowing; it is best to shake the seeds into the liquid spawn of Armillaria mellea, and then sow them.