ArticleAnnals of botany2025
Global variation in seed covering structure hardness of woody species with orthodox seeds.
Article in Annals of botany, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 2 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
2 citing papers in PubMed.
- Regeneration from seeds with physical defects: Contrasts in survival strategies in recalcitrant and orthodox seeds.Plant diversity · 2026Review
- Review
Corrections and comments
- Erratum issued
Authors and funding
10 authors.
Funding
Abstract
BACKGROUND AND
aimsSeed covering structure hardness may play a role in defence/predation, physical dormancy and in situ longevity/persistence. However, research to date has been limited regarding quantification methods, plant diversity and geographical distribution. In this study, we determined global variation in seed covering structure hardness of woody species with desiccation-tolerant seeds and analysed its relationships with relevant climatic variables, seed traits and ecological processes.
methodsWe measured seed covering structure hardness of 476 species from 459 genera and 113 families using puncture force. We used phylogenetically informed regressions to test covering structure hardness against potential quantitative predictors [19 climate variables (n = 405), ten seed morphological traits (n = 413), elevation (n = 405), genus age (n = 375)] and response variables [ex situ seed longevity (n = 67), germination rate (n = 82), species distribution/range size (n = 403)]. Categorical predictors [geographical region (n = 444), plant lifeform (n = 428), seed dormancy type (n = 146), seed physical dormancy in the family Fabaceae (n = 76), dispersal unit or mechanism (n = 484), fruit type (n = 427)] were tested using pairwise comparisons. KEY
resultsSeed covering structure hardness ranged from 0.13 to 366.38 N and seed and fruit (seed/fruit) size, seed/fruit roundness, seed/fruit colour (lightness) and precipitation of the driest quarter were significantly associated with hardness. In addition, dormancy types (vs non-dormancy), dispersal as fruit (vs seed) or certain fruit types (fleshy vs dry, drupes vs other types), as well as animal dispersal (vs other mechanisms) showed higher levels of hardness. Furthermore, covering structure roundness was higher in animal-dispersed seeds/fruits (vs other dispersal strategies). Finally, covering structure hardness was shown to predict germination rate but not ex situ seed longevity or species range size.
conclusionsOur results suggest roles for morphology, dormancy, dispersal and precipitation in explaining part of the global variation in seed covering structure hardness of woody species with orthodox seeds. However, we showed that the presence of physical dormancy does not always imply having a harder covering structure than non-dormant seeds and therefore terms such as 'hardseeded' or 'hard coat' should no longer be used as synonyms for this trait.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.