Cheilanthes clevelandii (Cleveland's Lip Fern)
Cheilanthes clevelandii
Table of Contents
Introduction & Discovery
Cheilanthes clevelandii, Cleveland's Lip Fern, is a distinctive small fern of the rocky chaparral and coastal sage scrub of southern California and northern Baja California, a species whose entire natural distribution falls within one of the world's five Mediterranean-climate regions and whose biology is intimately tuned to the long summer drought and mild wet winters that define that climate. The species was named in honour of Daniel Cleveland, a prominent late-nineteenth-century naturalist, collector, and co-founder of the San Diego Society of Natural History, who assembled extensive botanical collections from the San Diego region during the 1870s and 1880s and contributed significantly to the documentation of the southern California flora during a formative period in the region's botanical exploration. Morphologically C. clevelandii is distinguished from other southern Californian lip ferns by its combination of glandular-hairy rather than scaly frond undersides, its slightly viscid adaxial surface that feels tacky to the touch, and its consistent preference for non-calcareous rocky substrates within the chaparral vegetation zone. The species belongs to the cheilanthoid clade of the Pteridaceae, a lineage characterised by xerophytic adaptations including dense indumenta of hairs, scales, or glands, revolute margins functioning as false indusia, and poikilohydric desiccation tolerance that allows fronds to survive extended periods without any water supply. Molecular phylogenetic work by Michael Windham, Amanda Grusz, Kathleen Pryer, and colleagues has reshaped the taxonomy of the cheilanthoids, demonstrating that Cheilanthes in its traditional broad sense is polyphyletic, and C. clevelandii is now sometimes placed in the resurrected genus Myriopteris, though the classical name remains in wide horticultural use and in California floristic literature. For gardeners in Mediterranean climates the species offers a genuinely local native fern of considerable charm and ecological interest, well suited to rock gardens, crevice plantings, and xeric native-plant compositions where its dark wiry stipes and finely dissected fronds provide delicate textural contrast against the broader foliage of chaparral shrubs and coastal succulents.
Discovery & Naming
Cheilanthes clevelandii was described in the late nineteenth century from material collected in San Diego County, California, and was named in honour of Daniel Cleveland (1838-1929), a lawyer, naturalist, and co-founder of the San Diego Society of Natural History who devoted much of his life to the study and documentation of the southern California flora. Cleveland was an active field collector who corresponded with leading botanists of his era including Asa Gray at Harvard and Edward Palmer, and his botanical collections from the San Diego region during the 1870s and 1880s contributed to the floristic knowledge of a region then still poorly explored botanically. The species was initially placed in Cheilanthes and has remained there in most regional floras, horticultural references, and native-plant guides. Molecular phylogenetic work by Windham, Grusz, Pryer, and colleagues in the late twentieth and early twenty-first century associated the species with the Myriopteris clade, and some modern systematic treatments cite it as Myriopteris clevelandii. The taxonomic history of the species includes discussion of its relationship to the broader glandular-viscid complex of Californian lip ferns, and some treatments have separated or synonymised related taxa within this group. The species remains well recognised and nomenclaturally stable in California floristic literature.
Native Range & Distribution Map
Distribution map showing the native range of Cheilanthes clevelandii.
Biology & Frond Morphology
Cheilanthes clevelandii belongs to the genus Cheilanthes in the family Pteridaceae, producing evergreen, monomorphic, bipinnate to tripinnate fronds of small to moderate size, commonly 10 to 30 centimetres long and 3 to 8 centimetres wide, arising in dense tufts from a compact ascending rhizome. blades are lanceolate to narrowly oblong-lanceolate in outline, finely dissected into small oblong to rounded ultimate segments of 1 to 4 millimetres across. the adaxial surface is medium green and bears scattered short glandular hairs that give it a slightly viscid feel in fresh material, a tactile character that helps distinguish the species from non-glandular congeners in the field. the abaxial surface is covered with a moderately dense layer of pale tan to whitish stellate and glandular hairs rather than the flat scales of many related species, producing a softly woolly undersurface without the heavy felted density of the most extreme desert lip ferns. stipes are dark reddish-brown to nearly black, wiry, lustrous, and approximately one-quarter to one-half the total frond length, with scattered glandular hairs and small dark scales at the base. the revolute margins of the ultimate segments partially enclose the sporangia in the characteristic cheilanthoid false indusium. when fronds curl during drought they expose the paler, glandular-hairy undersides, giving the desiccated plant a distinctly greyish appearance. fronds that unfurl from coiled fiddleheads (croziers). Like all ferns, it reproduces via spores borne on the underside of fertile fronds rather than flowers and seeds, and its life cycle alternates between a dominant sporophyte (the visible plant) and a small, short-lived gametophyte stage.
Reproduction & Propagation
Propagation of Cheilanthes clevelandii can be achieved through several methods:
- Spores: Collect ripe spores from the underside of fertile fronds, sow on sterilised peat or peat/perlite mix. Do not cover. Keep humid and in bright indirect light. Prothalli (gametophytes) typically develop in 4–12 weeks, and young sporophytes appear after a further 2–6 months.
- Division: Mature clumps with multiple crowns or creeping rhizomes can be divided in spring as new fronds emerge.
- Rhizome cuttings / offsets: Epiphytic genera (Davallia, Polypodium, Phlebodium) can be propagated from 5–10 cm rhizome segments with at least one frond and visible roots.
Cultivation & Substrate
Successful cultivation of Cheilanthes clevelandii depends on matching three conditions to its natural habitat: consistent moisture without waterlogging, a humus-rich yet well-drained substrate, and the correct light level for its frond type — whether dappled woodland shade, bright filtered light, or, for a handful of rock ferns, direct sun.
Substrate: A sharply drained mineral mix of approximately 60 percent coarse mineral material (decomposed granite, granite grit, pumice, or crushed non-calcareous rock in particles of 3 to 8 millimetres) and 40 percent well-drained loam-based compost with low to moderate organic content. The finished mix should feel distinctly gritty and drain within seconds of a thorough soaking. Slightly acidic to neutral, pH 5.5 to 7.0. The species shows a preference for non-calcareous substrates in the wild and performs best in cultivation on granite or sandstone-derived mixes. Strongly alkaline conditions above pH 7.5 may reduce vigour and cause chlorotic foliage. Free and sharp drainage is essential and non-negotiable. Plant in raised positions, rock crevices, or containers with generous drainage holes and a coarse gravel layer at the base. Water should disappear from the surface within seconds of application. Standing water at the crown even briefly during warm weather is fatal. Low. The species grows naturally in nutrient-poor mineral substrates derived from weathered rock and requires very little supplementary feeding. A single midwinter application of dilute balanced fertiliser at one-quarter standard strength is adequate for container plants; open-ground specimens rarely need any feeding. Low, approximately 10 to 20 percent of the total mix volume. Use only well-decomposed leaf mould or screened fine compost, avoiding peat, coir, and fibrous bark that retain excessive moisture. The organic fraction provides modest moisture buffering and cation exchange capacity but must remain a minor component of the mix.
Water: Tap or rainwater, dry between
Light: Full sun to light shade, with the most compact and characteristic growth produced under high light levels that replicate the open rocky exposures of the native chaparral and coastal sage scrub habitats. In cultivation the species performs best in positions receiving four to eight hours of direct sunlight daily, particularly in cool coastal gardens where fog and marine influence moderate summer heat. In hot inland valleys of southern California and similar Mediterranean-climate regions, light afternoon shade from a rock overhang, trough rim, or neighbouring low shrub is beneficial during the hottest part of summer to prevent frond scorch without significantly reducing light. Deep shade produces weak, elongated fronds with reduced glandular hair production and thinner stipes, increasing vulnerability to fungal problems and yielding a lax, unattractive specimen. The bright, fog-filtered coastal light of the southern California littoral is ideal and produces the most vigorous, compact, and well-haired fronds. Reflected light and radiant warmth from surrounding stone and pale-coloured gravel surfaces enhance growth by mimicking the high-albedo rocky environment of the wild.
Humidity: 20-50% (tolerant)
Common Mistakes to Avoid
Applying year-round watering to a species adapted to strict Mediterranean seasonality is the most common and fatal error in cultivation; summer irrigation in warm conditions almost invariably causes crown rot and death, often within weeks. Planting in organic-rich, moisture-retentive soil or conventional potting compost replicates none of the conditions of the native rocky chaparral habitat and produces waterlogged roots. Deep shade produces weak etiolated growth with reduced glandular hair production. Failing to provide sharply drained mineral substrate kills more plants than any pest or disease. In non-Mediterranean climates, neglecting to provide overhead shelter or alpine-house protection from summer rain exposes the crown to warm wet conditions that are rapidly fatal. Confusing C. clevelandii with the ecologically different Polypodium californicum, which shares some rocky habitats but requires summer shade and moderate moisture, leads to inappropriate care. Over-feeding produces soft pale growth uncharacteristic of the species. Burying the crown below grade invites rot.
Seasonal Considerations
Autumn is the season of renewal as the return of cool-season rains triggers the primary flush of new fronds from October through December. Remove old tattered fronds in early October before the new growth emerges, apply a single light feed at one-quarter standard strength to container plants, and begin moderate watering as autumn rains become established. Winter is the most active growing season, with fronds at their peak condition from December through February; maintain regular moderate watering every seven to ten days if natural rainfall is insufficient, and monitor for fungal leaf spot during prolonged wet periods. Spring growth continues through March and April, with the beginning of spore maturation on fertile fronds; reduce watering frequency gradually as temperatures rise and rainfall diminishes through April and May. By May the species should be transitioning to dry summer dormancy; cease watering entirely in Mediterranean climates or reduce to rare minimal soakings in non-Mediterranean settings. Summer is the dormant season from June through September; fronds may curl partially and appear drab or silvery as the glandular-hairy undersides become prominent. Do not be alarmed by this appearance and do not water to revive them. The return of autumn rains will trigger the natural recovery and renewal cycle. Spore collection is possible from late winter through mid-spring.
Diseases & Pests
Common issues affecting Cheilanthes clevelandii in cultivation:
- Root/rhizome rot: Caused by waterlogged substrate, compacted soil, or overwatering in cool weather. Ensure the growing medium is well-aerated and never let pots sit in standing water for prolonged periods.
- Fungal leaf spot & Botrytis: Brown or grey blotches appear in stagnant, overly humid conditions. Improve air circulation, remove affected fronds, and avoid wetting foliage late in the day.
- Scale insects & mealybugs: The most common fern pests, hiding on stipes and frond undersides. Wipe off with a cotton swab dipped in diluted isopropyl alcohol, or treat with horticultural soap. Many chemical pesticides scorch fern fronds — always test on one frond first.
- Spider mites: Fine webbing and stippled fronds, common in dry indoor air. Raise humidity and rinse fronds regularly with tepid water.
- Frond browning (tip burn): Caused by dry air, direct hot sun, fluoridated or chlorinated tap water (especially in Nephrolepis, Calathea-loving filmy ferns), or soluble-salt build-up from fertiliser. Flush the pot with rainwater and reduce feeding.
Indoor Growing & Terrariums
Cheilanthes clevelandii can be grown indoors as a houseplant or terrarium subject when its humidity and light requirements are met.
Indoor Setup
- Light: Bright indirect light — an east- or north-facing window, or 30–60 cm under an LED grow light (10–12 hours/day). Most ferns scorch in direct midday sun.
- Humidity: 50–80%. Group plants, stand pots on a pebble-and-water tray, or run a humidifier; misting alone rarely raises ambient humidity enough.
- Temperature: 16–24°C (60–75°F) for most indoor species; avoid cold drafts and hot radiators.
- Substrate: Peat-free potting mix with added perlite and orchid bark for drainage; epiphytic genera (Platycerium, Davallia) grow best mounted on bark or in a bark-heavy orchid mix.
- Water: Keep consistently moist but never waterlogged. Let the top 1–2 cm of substrate dry slightly between waterings in winter.
- Air circulation: A gentle fan discourages fungal leaf spot without drying out the fronds.
Landscape & Garden Use
Cheilanthes clevelandii can be used in the garden wherever its hardiness and habitat preferences are matched. Ferns are classic choices for shaded borders, woodland gardens, stumperies, rockeries, stream-side plantings, and ground-cover under trees.
Landscape Tips
- Companions: Hostas, Astilbe, Heuchera, Tiarella, Epimedium, hellebores, snowdrops and other shade-tolerant perennials are classic partners.
- Soil preparation: Incorporate leaf mould or composted bark to improve moisture retention and mimic a forest floor.
- Mulching: A 3–5 cm mulch of chipped bark or leaf litter protects the rhizomes, conserves moisture, and slowly releases nutrients.
- Watering: Establish new plantings with regular deep watering during the first growing season; most hardy ferns need only occasional supplemental irrigation once established.
Conservation & Collector Notes
Cheilanthes clevelandii is not currently listed as threatened at the federal level in the United States or under CITES. NatureServe ranks it as apparently secure across its overall range in southern California and northern Baja California. However, the species' concentration in the rapidly urbanising coastal strip of southern California, one of the most intensively developed landscapes in North America, means that individual populations face ongoing habitat loss from residential and commercial development, road widening and infrastructure construction that destroys cliff habitats, altered fire-management practices that either suppress fire entirely or impose prescribed burns of different intensity and frequency than the natural regime, and recreational activities including hiking trail construction and rock climbing on occupied cliff faces. Populations on public lands within national forests, state parks, and local open-space preserves are better protected but not immune to management impacts. Climate change projections for southern California suggest increased drought frequency and duration, potentially extending the summer dry season beyond the species' tolerance, as well as increased fire frequency that could damage populations already stressed by drought. The species' inherent drought tolerance provides some buffer against these changes. No significant commercial collection pressure exists; all cultivated material derives from spore-raised or nursery-divided stock.
Collector Notes
Cheilanthes clevelandii is a valued species for collectors of California native plants and specialist fern enthusiasts, representing the chaparral rock-fern niche of the California Floristic Province. Provenance is valuable: plants from different parts of the species' range, including coastal San Diego County, the Santa Monica Mountains, the San Gabriel Mountains, and the Baja California sierras, may differ in drought tolerance, cold hardiness, and growth phenology, and documented provenance collections contribute to understanding geographic variation. The Southern California Botanists, the California Native Plant Society (particularly the San Diego and Los Angeles chapters), and the Theodore Payne Foundation periodically offer spore, plants, or seeds of California native species including this one. No formally named cultivars are recognised. Wild collection requires permits from relevant state and federal land management agencies and should be limited to modest spore harvests from abundant populations. Notable cultivated specimens are maintained at the California Botanic Garden in Claremont, the Santa Barbara Botanic Garden, the San Diego Botanic Garden, and the Regional Parks Botanic Garden in Tilden Park, Berkeley. A well-sited rock-garden specimen in a Mediterranean-climate garden is essentially permanent, persisting for decades with minimal care once established.
Ethnobotany & Cultural Significance
Published ethnobotanical documentation specific to Cheilanthes clevelandii is very limited, consistent with the general pattern for small cryptic cliff ferns that produce insufficient biomass for significant utilitarian harvesting. The Kumeyaay, Luiseno, Tongva, Chumash, and other Indigenous peoples of southern California possessed extensive and sophisticated botanical knowledge and employed hundreds of native plant species for medicine, food, fibre, and ceremonial purposes, but small rock ferns of the cheilanthoid group are very rarely mentioned in published ethnographic records from the region. Broader documentation of Indigenous plant use in coastal southern California occasionally references fern-like plants in medicinal or ceremonial contexts, but specific identification to C. clevelandii rather than to other ferns or fern allies in the same habitats is not confirmed in the published literature. The species' modern cultural significance is primarily horticultural and scientific, as a valued component of southern California native rock-garden plantings, as a subject of systematic and biogeographic study within the California Floristic Province, and as an example of the notable adaptive radiation of cheilanthoid ferns into Mediterranean-climate rock habitats.
Frequently Asked Questions
Who was Daniel Cleveland and why is this fern named after him?
Daniel Cleveland (1838-1929) was a lawyer, naturalist, and co-founder of the San Diego Society of Natural History who assembled important botanical collections from the San Diego region in the late nineteenth century. His fieldwork during the 1870s and 1880s contributed significantly to the documentation of the southern California flora, and the species was named in his honour by the describing botanist in recognition of his contributions to regional natural history.
Why should I stop watering this fern in summer?
C. clevelandii is adapted to the Mediterranean climate of southern California where summers are essentially rainless for four to six months. The species enters a natural semi-dormancy during the dry season, reducing metabolic activity and partially curling its fronds. Watering during this period, particularly combined with summer warmth, creates exactly the warm-wet conditions that favour the Pythium and Phytophthora oomycetes that cause fatal crown rot. Summer dryness is not optional; it is a fundamental cultural requirement.
Can I grow Cleveland's Lip Fern in a climate with summer rain?
Yes, but you must provide overhead shelter to keep the crown and root zone dry during the warm months. An alpine house, transparent rain cover, or deeply recessed rock crevice with a substantial overhanging stone provides the necessary protection. The species is fundamentally incompatible with warm wet conditions and will develop crown rot without enforced summer dryness.
How do I distinguish C. clevelandii from C. covillei in the field?
Examine the frond underside with a hand lens or strong magnifier. C. clevelandii has soft glandular and stellate hairs that feel slightly viscid or sticky to the touch. C. covillei has flat, non-glandular, bronze-coloured scales that feel dry and papery. The glandular versus scaly distinction is diagnostic and readily confirmed at moderate magnification.
Does fire harm or benefit this species?
Fire is a natural and ecologically important factor in the chaparral vegetation where this species grows. Above-ground fronds are consumed by moderate surface fires, but rhizomes sheltered deep within rock crevices survive and resprout rapidly. Post-fire conditions with reduced competition from shrubs and increased light availability often benefit the species, and it is typically among the early pteridophytes to reappear on burned rocky substrates.
Explore Our Other Encyclopedias
12,000+ expert articles on tropical & exotic plants
Quick Reference Summary: Cheilanthes clevelandii
Golden Rule: Match moisture, light and humidity to each fern’s natural habitat — woodland ferns need shade and humus, rock ferns need drainage, filmy ferns need constant humidity.
Cheilanthes clevelandii, Cleveland's Lip Fern, is a compact xerophytic fern of 10 to 30 centimetres endemic to the rocky chaparral and coastal sage scrub of southern California and northern Baja California. Distinguished from other regional lip ferns by its glandular-hairy rather than scaly frond undersides and its slightly viscid adaxial surface, the species is precisely adapted to the strict Mediterranean climate of its range, growing actively during mild wet winters and entering deep dry dormancy through the rainless summers. Hardy in USDA zones 9 to 11, it thrives in crevice gardens and rock plantings with sharply drained mineral substrate and full sun. In non-Mediterranean climates it requires summer rain protection via alpine house or overhead cover. Propagation is by spore or division. Named for the prominent San Diego naturalist Daniel Cleveland, the species is a charismatic representative of the California Floristic Province and a rewarding subject for native-plant and rock-garden enthusiasts.