Selaginella tamariscina (Resurrection Spikemoss, Rose of Jericho (East Asian), Juan Bai (卷柏), Iwahiba (岩檜葉), Bugwoochi, Tamarisk Spikemoss)
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Selaginella tamariscina
Table of Contents
Introduction & Discovery
Selaginella tamariscina is the celebrated resurrection spikemoss of East Asia, an ancient botanical icon that for more than two thousand years has featured in Chinese and Korean materia medica, classical poetry, and the horticultural culture of the rock garden and bonsai companion planting. Like its New World counterpart Selaginella lepidophylla of the Chihuahuan Desert, S. tamariscina is capable of surviving prolonged complete desiccation and reviving within hours on exposure to water, but it occupies a different set of habitats (sunbaked rock outcrops rather than desert plains), displays a different growth form (a compact upright rosette on a short woody caudex rather than a spreading rosette of slender stems), and carries a substantially older and more elaborate human cultural history. The species is known in Chinese traditional medicine as 卷柏 (juan bai, meaning roughly curled cypress) and is documented in the Shennong Bencao Jing, the foundational Chinese materia medica compiled in approximately the first to second centuries of the Common Era, where it is described for use in circulatory and menstrual regulation and in preparations for minor injuries. In Korean ethnomedicine it carries the name bugwoochi and features in similar contexts. In Japanese it is iwahiba (rock cypress) and in Japanese horticulture is particularly associated with the highly developed tradition of iwahiba cultivation, in which selected clones are grown as miniature rock specimens in decorative shallow pots in a manner analogous to bonsai; hundreds of named cultivars of varying foliage colour, rosette form, and degree of caudex development have been selected over several centuries of Japanese cultivation. Taxonomically the plant belongs to Selaginellaceae, the monogeneric family of lycophytes that is sister to the rest of living pteridophytes alongside Isoetaceae, and displays all the diagnostic features of the genus: single-veined microphylls in four ranks, a minute membranous ligule on the adaxial base of each leaf, rhizophores in place of true primary roots, and heterosporous strobili bearing both large megaspores and small microspores. The biochemistry of its desiccation tolerance, including production of trehalose and related sugars and a distinctive suite of selaginellin phenolic compounds first isolated from this species, has been extensively studied and represents one of the most important research contributions of the genus to contemporary plant science.
Discovery & Naming
The genus Selaginella was established by the French botanist Palisot de Beauvois in 1804 and formally circumscribed in his Prodrome des cinquième et sixième familles de l'Aetheogamie of 1805, as a segregate of the Linnaean Lycopodium intended to accommodate the heterosporous ligulate species. Selaginella tamariscina, however, was known to East Asian scholarship for nearly two thousand years before its formal Linnaean description: it is recorded under the name 卷柏 (juan bai) in the Shennong Bencao Jing, the foundational Chinese materia medica compiled approximately in the first to second centuries of the Common Era, and in successive Chinese pharmacopoeial texts through the medieval and early-modern periods. Linnaean naming came in the late eighteenth century through collections made by European botanists from Chinese and Japanese gardens; the specific epithet tamariscina refers to the tamarisk-like appearance of the branching sprays. The species was referenced in Linnaeus's own works and in nineteenth-century pteridological monographs including those of Spring and Hieronymus. In Japan dedicated iwahiba (rock cypress) cultivation manuals were published during the Edo period (1603 to 1868), coinciding with broader Japanese horticultural flourishing under Tokugawa patronage, and by the nineteenth century hundreds of named cultivars were established. European awareness of iwahiba as a cultural phenomenon grew during the late nineteenth and early twentieth centuries as Japanese horticultural traditions entered Western consciousness. Modern phytochemical investigation began in earnest in the mid-twentieth century and has produced an extensive literature on biflavonoids and selaginellins; the class name selaginellin derives from isolation of the compound in this species by Chinese research teams in the 2000s. Molecular phylogenies in the twenty-first century have placed S. tamariscina in an East Asian clade within Selaginella.
Native Range & Distribution Map
Distribution map showing the native range of Selaginella tamariscina.
Biology & Frond Morphology
Selaginella tamariscina belongs to the genus Selaginella in the family Selaginellaceae, producing evergreen, rosette-forming, remarkably desiccation-tolerant lycophyte producing upright to ascending leafy stems that arise from a short thick erect woody caudex, not true fronds. the caudex builds up over years into a small gnarled trunk a few centimetres tall clothed in persistent leaf bases and dead stem remnants, above which radiate fresh green branching sprays in a vase-like or rosette arrangement 8 to 20 centimetres across. branches are pseudo-dichotomously divided into flattened frond-like ultimate sprays clothed in four ranks of small microphylls: two lateral ranks of larger ovate-acuminate leaves and two median ranks of smaller appressed acuminate leaves. each microphyll bears a minute membranous ligule on the adaxial base, diagnostic of selaginellaceae. on desiccation the whole rosette curls inward into a tight brown ball, protecting inner tissues from sun and dehydration; on rehydration it unfurls within hours into a vivid green rosette resuming photosynthesis. strobili are small, quadrangular, and terminate short erect lateral branchlets. 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 Selaginella tamariscina 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 Selaginella tamariscina 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 gritty, free-draining, mineral-dominated medium resembling thin rocky soil. A reliable blend is 60 to 70 percent fired Japanese clay (akadama) or equivalent baked clay granules, 20 percent coarse sand or fine gravel, and 10 to 20 percent sieved leaf mould or composted bark fines. Avoid peat-dominated potting compost. For outdoor rockery use, mix one part grit with one part sandy loam and one part organic matter. Neutral to mildly alkaline is well tolerated, pH 6.0 to 7.5, reflecting the species' broad habitat range across granitic and limestone substrates. Strongly acidic peat-based mixes are unsuitable. The species is one of the more pH-flexible Selaginellas. Excellent drainage is essential. The substrate must drain freely within seconds of watering and must not retain standing moisture around the caudex. Use shallow broad containers with large drainage holes, and where garden soil is heavy plant on raised rockery positions or in troughs rather than at grade. Low fertility is preferred. The species evolved on mineral-poor rocky substrates and grows compactly under lean conditions; rich fertilisation produces soft etiolated growth and loose rosette form. A quarter-strength balanced liquid fertiliser once a month during the growing season is ample; skip feeding in winter and during any intentional desiccation phase. Low to moderate. Unlike most Selaginellas, S. tamariscina does not require a humus-rich substrate and indeed performs better on largely mineral mixes with only a small component of organic material. Avoid incorporating peat or coir as more than a minor ingredient. Annual top-dressing with a thin layer of fine grit rather than organic mulch suits traditional iwahiba practice.
Water: Rainwater or soft tap
Light: Bright light with some direct morning or late afternoon sun is well tolerated and indeed preferred for development of the compact rosette habit and dense branching characteristic of this species. Unlike most ornamental spikemosses, which require shaded culture, S. tamariscina thrives in fully exposed positions in its native range and handles direct sun that would scorch S. kraussiana or S. uncinata within hours. For outdoor cultivation an east-facing, south-east-facing, or lightly south-facing position with protection from the harshest mid-day summer sun works well; in hot inland climates afternoon shade is beneficial. In indoor cultivation a bright east or south window provides appropriate light; the plant is one of the few Selaginellas that tolerates a sunny windowsill. Under deep shade the rosette opens out into a looser arrangement and growth becomes less compact. Under supplementary grow lighting 200 to 400 micromoles per square metre per second of photosynthetically active radiation on a 12 to 14 hour photoperiod suits best. Light is the single most important factor in achieving the characteristic tight rosette form; insufficient light produces a sparse sprawling specimen.
Humidity: See species profile
Common Mistakes to Avoid
The commonest mistake with Selaginella tamariscina is treating it like a conventional moisture-loving Selaginella and keeping it continuously wet. The species resents saturated substrate and over time develops soft etiolated growth, loose open rosettes, caudex rot, and fatal decline. A second common error is using a peaty organic-rich substrate: the species requires a gritty free-draining mineral-dominated medium (akadama, coarse sand, fine gravel) resembling its native rocky habitat. A third is planting the caudex too deeply, with the thick woody stem base buried under fresh substrate, which causes basal rot; keep the caudex surface above substrate level. A fourth is growing the plant in deep shade, which produces an open sparse rosette rather than the tight compact form that is the species' chief horticultural asset; provide bright light with some direct sun. A fifth is mistaking the desiccated curled brown state for death and discarding the plant; check for revival by hydration before giving up. A sixth is excessive feeding; quarter-strength is the safe upper limit. A seventh is sourcing wild-collected material from East Asian habitats where the species is under collecting pressure; buy nursery-propagated stock. An eighth is neglecting winter protection in zone 6 marginal plantings. A ninth is using a deep pot; shallow broad containers suit the species best and support the traditional iwahiba aesthetic.
Seasonal Considerations
Spring (March to May): active growth resumes as temperatures rise. Rehydrate any desiccated plants by immersing pots in a tray of soft water, and water regularly once growth is underway. Repot pot-bound specimens into fresh akadama-based substrate, tease out old roots, and divide mature clumps if desired. Begin quarter-strength liquid feeding once a month. Move indoor specimens to their summer light positions. Summer (June to August): peak growth in warm bright conditions. Water regularly but allow some drying between waterings; the species resents continuous saturation. Outdoor plantings may experience natural cyclical drying in rain-free periods, which is beneficial. Protect from the harshest afternoon sun in hot inland climates. Feed monthly at reduced strength. Autumn (September to November): growth slows as daylength shortens. Reduce feeding, then stop. Collect ripe strobili for spore experiments if desired. In northern zones prepare winter protection for outdoor plantings: a loose mulch of conifer boughs, bracken, or leaf litter over rockery specimens in zones 6 and marginal 7. Winter (December to February): outdoor plants in zones 6 and 7 enter the desiccated dormant state and are protected by mulch and snow cover. Indoor plants continue to grow slowly under bright winter windows; water lightly when the substrate dries and avoid cold draughts. Rotate pots for even light under short days. Traditional iwahiba growers often deliberately dry plants during winter to preserve compact form.
Diseases & Pests
Common issues affecting Selaginella tamariscina 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
Selaginella tamariscina 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
Selaginella tamariscina 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
Selaginella tamariscina has not been evaluated as threatened at global scale under IUCN Red List criteria, but its status varies considerably across its large East Asian range. In parts of China, Korea, and Japan where the species has been intensively wild-collected for both ornamental horticulture and traditional medicine, local populations have been reduced or extirpated on accessible rock outcrops. Korean conservation literature has documented decline in some regional populations attributable to collecting pressure. In Japan the iwahiba cultivation tradition has driven centuries of wild collection of distinctive clones and has left some localised wild populations depleted, although mainstream modern iwahiba horticulture now relies overwhelmingly on vegetatively-propagated cultivated stock rather than continuing wild collection. Chinese regulations on wild harvest of medicinal Selaginella species have been progressively tightened but enforcement is uneven. Ex situ conservation is comprehensively assured by the species' extensive cultivation in botanical gardens, private collections, and the Japanese iwahiba cultivar pool. Habitat loss from quarrying, road construction, and urban development of rocky terrain is a more diffuse long-term threat. Responsible horticultural practice sources all cultivated material from nursery-propagated stock; collectors should never remove plants from wild populations, and purchasers should ask about provenance. The species is ecologically flexible and climate-tolerant and, assuming wild collection is restrained, is unlikely to face serious conservation threat at global scale.
Collector Notes
For serious collectors Selaginella tamariscina is a benchmark species whose traditional Japanese cultivation as iwahiba represents one of the most refined horticultural traditions associated with any lycophyte. The Japanese iwahiba pool includes hundreds of named cultivars developed over several centuries of selection, varying in rosette form (tightly compact to loosely open), branch curl pattern, foliage colour (fresh green, yellow-green, golden, bronze, sometimes with white or cream variegation), caudex development (short to exceptionally long and gnarled), and the pattern of seasonal colour change. Valuable cultivars include historic selections such as Kincho, Kinkou, and several variegated clones, each with documented lineage and traditional display conventions. Japanese enthusiasts display mature iwahiba specimens in shallow decorative pots, often paired with small ornamental rocks, in a presentation aesthetic parallel to bonsai display. Acquiring genuine Japanese iwahiba cultivars outside Japan is difficult because of biosecurity import restrictions and limited specialist trade; most Western collectors must rely on the type form and a few widely-circulated cultivars. Chinese and Korean horticultural traditions also include their own named selections, less well documented in Western literature. For provenance documentation, collectors should record the lineage of each clone, dates of acquisition and propagation, and growing conditions. Because the species is slow-growing and long-lived, a mature specimen represents decades of accumulated character and is an appropriate focal plant in a collection.
Ethnobotany & Cultural Significance
Selaginella tamariscina holds one of the most substantial ethnobotanical records of any lycophyte. In Chinese traditional medicine, under the name 卷柏 (juan bai, curled cypress), the species is documented in the Shennong Bencao Jing, the foundational Chinese materia medica compiled approximately in the first to second centuries of the Common Era, where it is listed among middle-grade drugs and used for preparations intended to regulate circulation, to address menstrual irregularities, to relieve minor injuries, and as a general invigorating tonic. The use continued through subsequent Chinese medical classics, including the sixteenth-century Bencao Gangmu of Li Shizhen, and remains in modern Chinese pharmacopoeial use. The dried whole plant (shengzhi juan bai) and a fire-processed form (zhi juan bai) are distinguished, the latter used principally for styptic and circulatory applications. Phytochemical investigations beginning in the mid-twentieth century identified the distinctive class of selaginellins from this species first, including selaginellin itself and subsequent congeners, along with biflavonoids (amentoflavone, hinokiflavone, robustaflavone, sciadopitysin) characteristic of the family. Many of these compounds show antioxidant, anti-inflammatory, and cytotoxic activities in laboratory assays, and several have been investigated as potential anticancer leads, although clinical validation remains limited. The desiccation-tolerance biochemistry (trehalose, sucrose, and related osmoprotectants) has been studied in parallel with ethnobotanical compound identification. In Korean ethnomedicine analogous uses are documented under the name bugwoochi. In Japanese horticultural culture the species has been grown as iwahiba (rock cypress) for centuries, with dedicated cultivation manuals dating at least to the Edo period (1603 to 1868) and hundreds of named cultivars developed; iwahiba cultivation was particularly associated with samurai-class amateurs in the Edo and Meiji periods.
Frequently Asked Questions
Is Selaginella tamariscina the same as the Rose of Jericho sold at novelty shops?
Two different plants are sold under the English name Rose of Jericho, and S. tamariscina is sometimes confused with both. Selaginella lepidophylla of the Chihuahuan Desert is the American resurrection spikemoss commonly sold as Rose of Jericho in the ornamental trade. Anastatica hierochuntica is a Middle Eastern flowering plant (Brassicaceae) also sold as Rose of Jericho, which mechanically unfurls when wet but does not actually revive biologically. Selaginella tamariscina, the East Asian resurrection spikemoss known in Chinese as juan bai and in Japanese as iwahiba, is biologically similar to S. lepidophylla in its cyclical revival but differs morphologically (upright rosette on a woody caudex) and ecologically (temperate rock outcrops rather than desert plains). All three are occasionally sold under overlapping common names in the retail trade; check the Latin name for certainty.
What is iwahiba and should I try to grow it?
Iwahiba (岩檜葉, rock cypress) is the traditional Japanese horticultural practice of cultivating selected cultivars of Selaginella tamariscina as miniature rock specimens in shallow decorative pots, developed over centuries particularly during the Edo period (1603 to 1868). The tradition involves several hundred named cultivars varying in rosette form, foliage colour, and caudex development, and a refined set of display conventions paralleling bonsai. Western growers interested in the species can apply core iwahiba principles (gritty akadama-based substrate, shallow pot, bright light with some sun, restrained watering, cyclical desiccation) without necessarily pursuing the specialised cultivar collection, and will find the species considerably more rewarding than treatment as a generic houseplant. Specialist iwahiba cultivars are difficult to source outside Japan but a thriving enthusiast community exists.
Can I use Selaginella tamariscina medicinally as described in traditional Chinese medicine?
The species has a long documented history in Chinese traditional medicine under the name juan bai and continues to be listed in modern Chinese pharmacopoeial standards, typically as a prepared product (raw sheng juan bai or fire-processed zhi juan bai) for circulatory and menstrual applications. However, self-prescribed use of home-grown ornamental material is strongly not recommended. Traditional preparations follow specific processing methods, dosing protocols, and combinations with other ingredients, and clinical use should be under the supervision of a qualified practitioner of traditional Chinese medicine. Some compounds isolated from the species show cellular toxicity at high concentrations, and pregnancy is a known contraindication in traditional use. Keep ornamental specimens for horticultural enjoyment and obtain any medicinal preparation from regulated sources.
My Selaginella tamariscina has dried into a brown ball. Is it dead?
Almost certainly not. The dramatic drying and curling of the rosette into a tight brown ball is the species' celebrated resurrection response, a normal part of its biology that allows it to survive weeks, months, or even years of complete desiccation. To revive, place the pot in a shallow tray of soft water for several hours; the branches will uncurl and turn green within a few hours, and photosynthesis resumes within a day. After full hydration, resume normal watering and care. This cycling can be repeated many times over years without harm; indeed cyclical drying and rewetting is part of traditional iwahiba practice and often maintains better compact rosette form than continuous hydrated culture. A dead plant will not revive after hydration within 24 to 48 hours and will begin to show blackening and decay rather than greening.
Why is my plant flopping open into a loose sprawling form?
A loose open rosette in Selaginella tamariscina usually indicates insufficient light, excessive fertility, or continuous saturation that has produced soft etiolated growth. The species is adapted to exposed rocky habitats and needs bright light with some direct sun to maintain the tight compact rosette form that is its chief horticultural asset. Move the plant to a brighter position (a sunny windowsill or well-lit rockery), switch to a gritty mineral-dominated substrate rather than peaty compost, reduce feeding to quarter-strength once a month or less, and allow some drying between waterings. New growth under corrected conditions will be more compact; existing loose branches will not re-compact. A traditional remedy is a controlled desiccation period which forces the plant to regenerate its rosette in a tighter form when rehydrated.
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Quick Reference Summary: Selaginella tamariscina
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.
Selaginella tamariscina, the Resurrection Spikemoss or East Asian Rose of Jericho, is a rosette-forming desiccation-tolerant lycophyte native to rock outcrops across temperate and subtropical East Asia, from northern China and Russia to Japan and Taiwan. Known in Chinese traditional medicine as 卷柏 (juan bai) since the Shennong Bencao Jing of approximately the first or second century CE, and in Japanese horticulture as iwahiba with centuries of Edo-period cultivar development, it occupies a uniquely elaborate cultural and scientific position within the genus. It belongs to Selaginellaceae and displays all the diagnostic lycophyte features of single-veined microphylls in four ranks, a minute membranous ligule on each leaf, rhizophores, and heterosporous strobili with both megaspores and microspores, combined with the distinctive growth form of a compact upright rosette on a short woody caudex. The species revives from complete desiccation within hours of rehydration, a capacity paralleled in New World Selaginella lepidophylla. Hardy in USDA zones 6 to 10, it is the most climatically flexible Selaginella in cultivation, tolerating full sun, cold winters, and dry periods. It requires gritty mineral-dominated substrate, free drainage, bright light, and restrained watering; continuous saturation and peaty substrate cause decline. Propagation is by division, cuttings, or spores. Phytochemistry includes biflavonoids and selaginellins of ongoing research interest.