El Sedum sediform is a perennial succulent family Crassulaceae, known in Spanish as Cat's claw, bird grape, blackhead o always alive. The herbaceous appearance, forms dense clumps with stems crawlers that rise at their ends and reach 30 cm tall in flower (up to about 20 cm wide). It stands out for its leaves persistent, fleshy and colored glaucous blue-green, and for its star-shaped inflorescences of pale yellow tones, highly visited by pollinators in the warm season.
Its natural area extends across the mediterranean region and it is very common in the Iberian Peninsula and the Balearic Islands (with the variety dianicum in Ibiza and Formentera). Appears in very dry and sunny soilat walls and roofs to rock cracks, and can thrive from sea level to approximately 2000 m altitude. Due to its rusticity and low water requirements, it is a key species in xeriscape, ecological covers and rockeries.
Botanical characteristics
- Tallos: more or less lignified at the base, prostrate-ascending; the fertile ones have a lower density of leaves and end in branched inflorescences.
- Leaves: leathery and succulent, 10–15 × 2–5 mm; ovate-lanceolate to elliptical, sometimes somewhat flattened on the upper surface, with apex acute or mucronate and a small basal spur; color glaucous blue-grayThey persist all year round.
- Inflorescence: cymose or corymbose, with 5–8 opening cymes radially. Hermaphrodite flowers, pentamers to octamers, with a pale yellow or cream corolla.
- Flower: 5 sepals fused to the receptacle (2–3 mm), 5 petals up to 9,5 mm; androecium with twice as many stamens as petals; gynoecium with free carpels.
- Fruit: erect follicles with persistent style; seeds oblong, thin.
It blooms among late spring and summer extending even into early autumn depending on the climate. It is resistant to cold under conditions of 6 zone of rusticity, tolerating intense frosts once established. Variable chromosome counts have been cited (2n = 32 + (0–2)B, 40, 48, 56, 64, 96), a reflection of its plasticity.
Habitat, distribution and ecology
Colonizes incipient lithosols about limestone and siliceous, with very little substrate y excellent drainage. Is indifferent to the type of soil (stony, silty, sandy, clayey) and shows a great tolerance to pH, thriving in both basophilic environments and acidic substrates, provided drainage is excellent and fertility is low.
In the Mediterranean landscape it appears in communities of the alliance Sedion micrantho-sediformis (class Sedo‑Scleranthetea, order Alysso-Sedetalia), next to camephytes and other succulent perennials. It shares space with Helichrysum stoechas, Santolina chamaecyparissus, Sedum acre y Sedum album, typical of rocks, walls and very dry clearings.
Its ecological requirements are clear: full sun, low soil humidity and soils poor in nitrogen. Tolerates moderate disturbance (light trampling, occasional grazing), it sprouts again after droughts and spreads throughout fragmentation and by seed. Seed dispersal is local and non-specific (distance class 2: more than 0,3 m), favored by gravity and rain splashes.
Cultivation and care in gardening and roofs
Soil and substrate: uses mixtures for rupicolous plantsVery porous and with aggregates (pumice, gravel, coarse sand). In soil, it accepts almost any texture as long as the drainage is Excellent. Does not require deep soil; thrives in fissures and shallow layers.
Luz: prefer solar exposition direct. In very warm climates it can admit light semi-shade in the central hours, maintaining its glaucous color.
Irrigation: on the ground, often does not require summer watering once established. In a pot, water scarcely: in warm weather, a deep watering every 7–10 days depending on substrate and ventilation; in cold, Once a month or less. Avoid to puddle and let the substrate dry between waterings.
Fertilization: : not necessary. If desired, apply a very small amount light y spacing of low nitrogen fertilizer during the growing season.
Transplant: each 2–3 years In spring, renewing the substrate and thinning the plant if necessary.
Planting density: for upholstery or green roofs in full sun with little substrate depth, use 16–25 plants/m² depending on the desired coverage speed.
Resistance: tolerates strong frosts (equivalent to 6 zone) after acclimatization. It takes root quickly, is rustic against pests and is only compromised by excess moisture that promote rot.
Propagation: cuttings and seeds
Stem cuttings (fastest method): cut tips or segments and leave scar 24–48 h. Plant 1–2 cm deep in a tray or pot with succulent substrate, keep slightly damp and protected from currents. It takes root in 2–3 weeks. The use of rooting hormone accelerates and strengthens root emission.
Leaf cuttings (higher plant yield): remove healthy leaves, let dry for 1–2 days and bury only the basis a few millimeters. In a month they usually emit roots and shoots.
Time: spring and late summer-autumn These are optimal times due to their thermal balance. Avoid intense peaks of heat or cold.
Siembra: possible, but slower. Shallow sowing, diffuse light, very fine humidity and mild temperatures. When there is formed root ball, transplant to a larger pot or to the garden.
Ornamental, medicinal and culinary uses
Ornamental: ideal for low maintenance landscaping en rockeries, dry walls, wall cracks, roofs y planters shallow. It is of easy implantation and fast growth, excellent in green roofs in full sun where the substrate is minimal and drainage is maximum.
Regional: native, persistent, evergreen, adapted to coastal areas, carpets and rockeries. Its texture and glaucous color contrast with Helichrysum y santolina, and they live well with others crass , the Sedum acre o Sedum album.
Traditional medicinal: the aerial part has been used as healing and to relieve inflammations y mouth sores (application of leaf juice), as well as discomfort gastric y hepaticThese uses belong to ethnobotany and require professional judgment before any application.
Culinary: the tender leaves can be eaten raw o boiled, and have traditionally been consumed pickles with lemon and thyme or as a dressing for olives. Use sparingly and with knowledge of the species.
Vernacular names, taxonomy and synonyms
Common names: in Spanish, Cat's claw, crespinillo, lizard pinillo, always alive, shepherd's grapes, cruet; in Portuguese, erva-pinheira; in Asturian, wall fins; in Catalan, crespinell.
Nomenclature: published as Sedum sediform (Jacq.) Pau; basionym Sempervivum sediforme Jacq. It presents synonyms such as Petrosedum sediforme, Sedum altissimum, S. fruticulosum, S. lusitanicum (illegible noun), S. nicaeense. The generic name Sedum It comes from Latin and applies to several crassulaceae; its etymology is not reliably related to sedate not even with sit down.
Phenology and flowering
In temperate climates of the northern hemisphere, flowering is concentrated from late spring to summer and can extend to beginning of autumn depending on altitude and water regime. The umbellate inflorescences, with 5–8 peaks, open from the outside in; they stand out stamens with sometimes hairy filaments at the base and the tonality pale yellow of the petals. After setting, the erect follicles They release very fine seeds suitable for short-distance dispersal.
Excess of water: soft leaves, black base and watery neck indicate decayRemove affected parts, dry the substrate and resume spaced waterings.
Loss of glaucous color: is usually due to lack of light. Increase sun exposure gradually to avoid sunburn.
Slow coverage: increases planting density (up to 25 plants/m²) or combined with clump fragmentation to accelerate the cover.
Its rusticity, the low maintenance and the ability to grow with very shallow depth of substrate convert to Sedum sediform into a versatile ally in both home gardening and technical projects restoration y green roofsThe combination of glaucous leaves, starry blooms, and drought tolerance creates discreet, long-lasting compositions on walls, rockeries, and sunny borders.
