{{Short description|Plant adapted to growing in rock crevices}} [[File:Sedum obtusatum - Sierra stonecrop - Flickr - Matt Lavin (1).jpg|thumb|Sierra stonecrop is most common in crevices of rock outcrops and cliffs faces.]] A '''chasmophyte''', or a '''crevice plant''',<ref name=sage/> is a plant adapted to grow in rock crevices, cliff faces, stone walls, and other narrow fissures where soil is sparse or absent. The term is derived from the Greek words chasma ("crevice" or "gorge") and phyte ("plant").<ref>{{cite journal |last=Zhao |first=Z. |title=Cliff-dwelling plants: rare and precious species in harsh habitats |journal=Frontiers in Plant Science |year=2025 |volume=16 |article-number=1535385 |doi=10.3389/fpls.2025.1535385 |doi-access=free |pmid=40391033 |pmc=12086150 |bibcode=2025FrPS...1635385Z }}</ref><ref name=journal>{{cite journal |last1=Das |first1=Sourav |last2=Roy |first2=Ria |last3=Kumar |first3=Ashwani |title=Deciphering the genetic and functional diversity of cultivable bacteria associated with chasmophytes and their role in plant growth promotion and rock weathering |journal=Frontiers in Microbiology |volume=13 |year=2022 |issue=9 |page=242 |doi=10.1007/s13205-022-03278-0 |doi-access=free |pmid=36032512 |pmc=9399335 }}</ref> Chasmophytes acquire nutrients because they grow in fissures in rocks where soil or organic matter has accumulated.<ref>{{cite web |title=chasmophyte |url=https://extremeplants.org/glossary/chasmophyte/ |website=Extreme Plants |date=26 April 2017 |access-date=1 June 2026}}</ref> Chasmophytes are able to colonise rock fissures and crevices by exploiting the columns of humus and organic matter that accumulate within these interstices.<ref>{{cite web |title=Functional biodiversity of chasmophytic endemic herbaceous species |url=https://ortobotanico1545.it/en/progetto-scientifico/functional-biodiversity-of-chasmophytic-endemic-herbaceous-species/ |website=Orto Botanico di Padova |access-date=1 June 2026}}</ref>
In horticulture, '''crevice gardens''' have been used as a method of transforming disturbed or underutilised sites into planted landscapes that mimic natural rocky habitats.<ref name=ABC/> Common examples include low-growing herbs, succulents, bellflowers, and other plants that naturally occur on rocky outcrops, cliffs, and stone walls. <ref name=world>{{cite news |title=Meet the crevice garden: wild, sculptural and surprisingly easy |url=https://www.gardenersworld.com/news/meet-the-crevice-garden-wild-sculptural-and-surprisingly-easy/ |work=Gardeners' World |access-date=1 June 2026}}</ref> Chasmophytes differ from lithophytes in that the term refers specifically to plants growing in rock fissures, cracks, and crevices, whereas lithophytes include all plants that grow on or among rocks, including those rooted on rock surfaces.<ref name=sage/><ref>{{cite book |last=Benzing |first=David H. |title=Vascular Epiphytes: General Biology and Related Biota |publisher=Cambridge University Press |year=1990 |isbn=9780521266307 }}</ref>
==Habitat and adaptations== Chasmophytes are specialised for life in rocky environments, often developing extensive root systems capable of penetrating deep into cracks to access water, nutrients, and accumulated organic matter. They occur in a wide range of habitats, including mountain cliffs, limestone outcrops, volcanic rock formations, coastal headlands, and artificial stone structures.<ref>{{cite web |title=8220 Siliceous rocky slopes with chasmophytic vegetation |url=https://sac.jncc.gov.uk/habitat/H8220/ |publisher=Joint Nature Conservation Committee |access-date=1 June 2026}}</ref> They are adapted to survive in environments with limited water and nutrient availability. Research suggests that microorganisms associated with chasmophytes may contribute to their survival by promoting plant growth, facilitating nutrient acquisition, and enhancing rock weathering processes.<ref>{{cite journal |last1=Wagensommer |first1=Robert Philipp |title=Functional biodiversity of chasmophytic endemic herbaceous species |url=https://www.iris.unict.it/handle/20.500.11769/582990 |website=IRIS Università di Catania |date=29 July 2017 |access-date=1 June 2026}}</ref>
Chasmophytes may be found in both xeric and humid environments and include species from numerous plant groups, including ferns, succulents, shrubs, and flowering plants. Many possess adaptations that enable them to tolerate drought, temperature fluctuations, nutrient-poor substrates, and exposure to wind. Although some species are restricted to rocky habitats, others are facultative chasmophytes that can also grow in deeper soils.<ref>{{cite web |title=8210 Calcareous rocky slopes with chasmophytic vegetation |url=https://sac.jncc.gov.uk/habitat/H8210/ |publisher=Joint Nature Conservation Committee |access-date=1 June 2026}}</ref> Microorganisms associated with chasmophytes may help these plants adapt to and survive in the water- and nutrient-limited conditions of rock crevices.<ref name=journal/> Chasmophytic vegetation forms an important component of many cliff and rocky outcrop ecosystems and often supports specialised, endemic, and geographically restricted species.<ref>{{cite journal |title=Diversity, Distribution and Classification of Chasmophytic Vegetation in the Central Asian Mountains |url=https://www.journalssystem.com/asbp/Diversity-Distribution-and-Classification-of-Chasmophytic-Vegetation-in-the-Central%2C159549%2C0%2C2.html |journal=Acta Societatis Botanicorum Poloniae |year=2022 |access-date=1 June 2026}}</ref><ref>{{cite journal |last=Kontopanou |first=A. |title=Habitat Islands on the Aegean Islands (Greece) |journal=Diversity |year=2020 |doi=10.3390/d12010033 |doi-access=free |url=https://www.mdpi.com/1424-2818/12/1/33 |access-date=1 June 2026}}</ref><ref name=sage>{{cite journal |last1=Arya |first1=Vikrant |last2=Parmar |first2=Ranjeet Kaur |last3=Gill |first3=Amandeep Kaur |last4=Jamwal |first4=Anupam |title=Unveiling the Ecological and Pharmacological Perspectives of Lithophytic Life Form |journal=Journal of Pharmacology and Pharmacotherapeutics |volume=16 |issue=1 |year=2025 |pages=5–24 |doi=10.1177/0976500X241283127 |url=https://journals.sagepub.com/doi/10.1177/0976500X241283127 |access-date=1 June 2026}}</ref>
Some authors have subdivided lithophytes into exolithophytes, which grow on rock surfaces, and chasmophytes (or chasmolithophytes), which grow in rock crevices and fissures. The Danish botanist Eugenius Warming was among the pioneers of plant ecology and examined the relationships between plants and their environments. In his 1909 book ''Plantesamfund'', Warming discussed lithophytes as plants adapted to rocky habitats and described chasmophytes as plants rooted in rock clefts containing accumulated detritus. He also noted that lithophytes are capable of colonising steep, inclined, and exposed rock surfaces.<ref name=sage/>
==Associated microorganisms== Such microorganisms have also attracted interest for their potential applications in developing sustainable approaches to improving drought tolerance and reducing water stress in crop plants. Research has found that some bacteria associated with chasmophytes exhibit tolerance to environmental stress and possess traits that promote plant growth. Experimental studies have shown that these microorganisms can improve drought tolerance, nutrient uptake, growth, and yield in crop plants under water-limited conditions. Such findings have led to interest in the potential use of chasmophyte-associated bacteria in sustainable agriculture to help reduce the effects of water stress and improve crop productivity. Studies of bacteria associated with chasmophytes have found that they often possess traits that promote plant growth and enhance tolerance to environmental stress.<ref name=nature/>
Research on bacterial communities isolated from chasmophytic plants in the Ladakh region of India found that many strains were capable of improving nutrient availability, producing plant-growth-promoting compounds, and tolerating extremes of pH, salinity, temperature, and drought. Researchers have suggested that such microorganisms may contribute to the survival of chasmophytes in water- and nutrient-limited rock crevice environments and may have potential applications in sustainable agriculture.<ref name=nature>{{cite journal |last1=Das |first1=Sudipta |last2=Chakdar |first2=Hillol |last3=Kumar |first3=Adarsh |last4=Singh |first4=Rajni |last5=Saxena |first5=Anil Kumar |title=Chasmophyte associated stress tolerant bacteria confer drought resilience to chickpea through efficient nutrient mining and modulation of stress response |journal=Scientific Reports |volume=14 |year=2024 |issue=1 |article-number=12189 |doi=10.1038/s41598-024-58695-3 |pmid=38806526 |pmc=11133442 |bibcode=2024NatSR..1412189D }}</ref><ref>{{cite journal |last=Sharma |first=B. M. |title=Preliminary ecological studies on lithophytes and chasmophytes in South-West Nigeria |journal=Feddes Repertorium |volume=103 |issue=3–4 |pages=235–242 |year=1992 |doi=10.1002/fedr.19921030311 |url=https://onlinelibrary.wiley.com/doi/abs/10.1002/fedr.19921030311 |access-date=1 June 2026}}</ref>
==Cultivation and gardening== [[File:Cley tower mill - geograph.org.uk - 842815.jpg|thumb|''Centranthus ruber'' growing in a rock crevice, a habitat that provides access to deeper soil, moisture, and nutrients.]] Gardening writers have noted that many plants are well adapted to growing in cracks, crevices, walls, and paving joints where soil is shallow and moisture is limited. Such habitats favour species capable of tolerating drought, restricted root space, and nutrient-poor conditions. Gardening writers have also noted that paths and paved surfaces containing gaps, cracks, and soil-filled crevices can provide opportunities for cultivating small, low-growing plants. These plants may spread along the joints between paving stones, softening the appearance of hard landscaping, creating a weathered or naturalistic effect, and in some cases releasing fragrance when stepped on. Similar planting opportunities can be created by removing deteriorated mortar or cement from existing paving and replacing it with soil or compost.<ref name=news>{{cite news |title=Gardens: plants for cracks |url=https://www.theguardian.com/lifeandstyle/2013/jul/26/gardens-plants-cracks-paths |work=The Guardian |date=27 July 2013 |access-date=1 June 2026}}</ref>
Cracks and joints in patios and paving can accumulate soil, compost, and organic matter over time, allowing a variety of plants to establish themselves. Species such as forget-me-nots, Mexican fleabane, watercress, celery, lamb's lettuce, and mosses may colonise these spaces naturally. While some gardeners remove such growth through sweeping, weeding, or cleaning, others regard paving cracks as opportunities for cultivation. Horticultural sources have recommended species adapted to shallow, dry substrates which can soften the appearance of hard landscaping, provide seasonal colour and fragrance, and create a more naturalistic aesthetic. Variations in rock type, slope, drainage, and soil chemistry can be incorporated into their design to replicate a wide range of natural environments and plant habitats. Some projects have utilised recycled materials, such as broken concrete, arranged to resemble natural rock strata and create crevices, planting pockets, and microclimates.<ref name=alys>{{cite news |title=Alys Fowler: plants for patio cracks |url=https://www.theguardian.com/lifeandstyle/2015/jun/06/alys-fowler-plants-patio-cracks |work=The Guardian |date=6 June 2015 |access-date=1 June 2026}}</ref>
A crevice garden is a style of rock garden designed to mimic natural rocky habitats through the use of thin, upright slabs of stone, such as slate or sandstone, arranged to create narrow planting crevices.<ref name=world/> The soil-filled crevices provide drainage and growing conditions similar to those found in natural rock fissures, allowing roots to penetrate deeply between the rocks and making crevice gardens particularly suitable for many alpine and saxicolous plants. Depending on their orientation and exposure, crevice gardens can support either sun-loving or shade-tolerant species. Crevice gardens are inspired by naturally occurring geological formations created through processes such as mountain building, weathering, and erosion. Modern crevice gardening involves the use of upright or angled rocks arranged to create narrow gaps in which alpine and other rock-adapted plants can be grown. A key principle of crevice gardening is to replicate natural rocky habitats, creating arrangements that resemble naturally occurring outcrops and fissures.<ref>{{cite web |title=Crevice Gardens |url=https://www.nargs.org/crevice-gardens |publisher=North American Rock Garden Society |access-date=1 June 2026}}</ref> These gardens typically employ free-draining, low-nutrient substrates and are planted with drought-tolerant, low-growing species adapted to rocky environments. Advocates argue that crevice gardens can reduce maintenance requirements, reuse construction waste, increase habitat diversity, and recreate the appearance of natural alpine, coastal, or rocky landscapes.<ref name=ABC>{{cite web |title=Rockin' Crevice |url=https://www.abc.net.au/gardening/how-to/rockin-crevice/106547464 |website=ABC Gardening Australia |publisher=Australian Broadcasting Corporation |date=10 April 2026 |access-date=1 June 2026}}</ref>
==Examples== Examples of chasmophytes include:<ref>{{cite web |title=Plants for Corners, Cracks, and Crevices |url=https://harmonyinthegarden.com/2020/08/plants-for-the-4-cs-corners-cracks-crannies-crevices/ |website=Harmony in the Garden |date=August 2020 |access-date=1 June 2026}}</ref><ref name=news/><ref name=alys/> {{div col|colwidth=20em}} * ''Asarina procumbens'' * ''Campanula portenschlagiana'' (wall bellflower) * ''Campanula poscharskyana'' (trailing bellflower) * ''Corydalis lutea'' * ''Delosperma'' ‘Fire Spinner’ * ''Echeveria agavoides'' ‘Lipstick’ * ''Erigeron karvinskianus'' (Mexican fleabane) * ''Erinus alpinus'' * ''Ficus vasta'' * ''Hypericum aciferum'' * ''Hypericum decaisneanum'' * ''Lamprocapnos spectabilis'' * ''Leycesteria formosa'' * ''Matricaria chamomilla'' (camomile) * ''Mentha pulegium'' (pennyroyal) * ''Mentha requienii'' (Corsican mint) * ''Oreocarya cana'' * ''Oscularia deltoides'' (Pink Ice Plant) * ''Saxifraga crustata'' * ''Scabiosa solymica'' * ''Sedum kamtschaticum'' * ''Sedum rubrotinctum'' ‘Aurora’ * ''Sempervivum'' * ''Soleirolia soleirolii'' ("mind-your-own-business") * ''Telesonix jamesii'' * ''Thymus serpyllum'' (creeping thyme) {{div col end}}
==Gallery== <gallery> Struthiopteris spicant Craig Rhosyfelin Crevice.jpg|''Struthiopteris spicant'' growing from a crevice in Wales, UK Leycesteria formosa self-seeded on garden wall.jpg|''Leycesteria formosa'' growing out of a crack in the wall in Berrington, Northumberland File:Hemionites arifolia-roadside-yercaud-salem-India.JPG|''Parahemionitis arifolia'' in Yercaud, India File:A Coruña (provincia) 1992 52.tif|Plants in a slate crevice. Valdoviño, A Coruña, Galicia, Spain Campanula piperi, White form - Flickr - brewbooks.jpg|''Campanula piperi'' on rock crevices, Olympic National Park Taraxacum officinale - common dandelion - Flickr - Matt Lavin (1).jpg|Common dandelion prospering in the limestone crevices and cracks in the Bridger Range Pinus ponderosa brachyptera - 51826970481.jpg|Ponderosa Pine growing in rock crevices in the Sandoval County, New Mexico. Flickr - brewbooks - Life in the Alpine Zone - Wheeler Peak (2).jpg|''Heuchera rubescens'' in rock crack Common Butterwort (Pinguicula vulgaris) - geograph.org.uk - 823008.jpg|''Pinguicula vulgaris'', growing in a crevice in the rocks Perce-pierre.jpg|''Crithmum maritimum'' growing on a crevice in Brittany, France </gallery>
==See also== * Epibiont * Epiphyte * Endosymbiont * Epiphytic fungus * Epiphytic bacteria * Foliicolous
==References== {{reflist}}
Category:Plant morphology Category:Ecology terminology Category:Plant life-forms Category:Plants by habit Category:Lithophytes