Talk:Achene

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Discussion for: Achene • View • Links • Related changes

Use this page for verification notes, disputes, and action items. Keep narrative content on the article.

Page scope

Achene covers the fruit of Cannabis as a structure: how it develops from the female flower, the perianth, fruit wall and seed coat, which of these are tissue of the mother plant, the embryo and its stored food, how ripe fruits are shed or held and achenes recovered from burials. The characters used to describe and compare seed (size, weight, shape, colour, pattern, perianth and base) are treated at Seed morphology.

Data verification

Record source conflicts, figures that differ between studies and the limits of what each study tested. Keep narrative content on the article.

Discussion

Sources

Prakash, Bohm and Maze (1979), Canadian Journal of Botany: the development of the achene from the ovary in four varieties, the curvature of the nucellus after fertilisation, the curved embryo with two cotyledons filling most of the seed, food stored in the radicle, the cotyledons and one to several layers of endosperm, the thin seed coat with chloroplasts and little protective role, the enlargement and wall thickening of the endocarp and the absence of significant differences between the varieties.
Manansala-Siazon and colleagues (2025), Plants: the pericarp and seed coat as maternal tissue, the bract with glandular trichomes in which the seed develops, the oil, protein and carbohydrate content of hemp seed and the cross between a large-seeded Chinese variety and a small-seeded Syrian landrace in which first-generation seeds resembled the mother's.
McPartland and Small (2020), PhytoKeys: the perigonal bract and its other names, the perianth that forms no corolla and adheres to the exocarp, the wild-type traits first described by Zinger (1898), the domestication syndrome of the fruit and the retention of achenes in the dense infructescence of var. afghanica.
Small (1975), Canadian Journal of Botany: the fruit traits of wild and domesticated plants and the proposal that the wild syndrome is adaptive.
Naraine and colleagues (2020), Genetic Resources and Crop Evolution: the test of pericarp resistance to fracture in herbarium achenes of ruderal, fibre, oilseed and marijuana plants.
Li and colleagues (2026), Journal of Pharmaceutical Analysis: the division of the achene into hull and kernel in 20 Chinese landraces, the hull as a by-product of processing and the location of measured compounds, cannabinoids among them, in the hull and the cotyledons.
The USDA hemp phenotyping and protocol handbook (version 4, 2025): the bag test for the shatter fraction.
Haney and Kutscheid (1975), The American Midland Naturalist: birds and small mammals feeding on hemp seed in Illinois and the authors' judgement of how far seed is spread and how long it lasts in soil.
Bai and colleagues (2021), Journal of Ethnopharmacology; Jiang and colleagues (2016), Economic Botany; Jiang and colleagues (2021), Vegetation History and Archaeobotany: the achenes from Laoguanshan, Jiayi and the tomb of the Haihun Marquis, their counts, dates, structure and sizes.

Where the sources disagree

Where the pattern on the fruit lies. Small (1975) and McPartland and Small (2020) place the mottling in the persistent perianth of wild-type fruits; Bai and colleagues describe a mosaic on the exocarp itself, easiest to see on cultivated fruits without a perianth. The point is set out on the seed morphology page.
The name of the bract. The bract round the female flower and fruit is called the perigonal bract, bracteole or perigonium; McPartland and Small call the name calyx, also in use, inappropriate.

How far the evidence goes

The maternal effect on seed size rests on one cross, in which the small-seeded Syrian landrace was the mother. The first-generation seeds were measured on 25 seeds per group.
Haney and Kutscheid's statement that viable seed lasts no more than two or three years in the soil is the authors' conclusion in their summary; the burial results they cite are earlier ones (Goss 1924 and a personal communication on Kansas seed).
The comparison of the two Laoguanshan tombs rests on 20 measured fruits from each and on their surface and base; the authors state it as a closer similarity to cultivated or to wild fruits.
The Haihun measurements are of seed coats alone, since nothing else of the achenes survived.
The compound measurements of Li and colleagues are from 20 Chinese landraces; they found no clustering of the achenes by region of origin.

Terms

Achene: a dry, one-seeded fruit that does not split open when ripe.
Perigonal bract: the small leafy bract enclosing the female flower and later the fruit.
Perianth: the thin membrane of the female flower that clings to the fruit.
Pericarp: the fruit wall, of exocarp (epicarp), mesocarp and endocarp; in trade, the hull.
Testa: the seed coat.
Abscission zone: the layer at the base of the fruit where it separates from the plant.
Shatter fraction: the share by weight of the seed that falls from a length of raceme.