Sesuvium Portulacastrum (L.) L

Sesuvium portulacastrum (L.) L. Sea Purslane (Portulaca portulacastrum)

Other Common Names: Cenicilla, Shoreline Sea Purslane, Shoreline Purslane. Family: Aizoaceae, subfamily Sesuvioideae. Cold Hardiness: Not well documented, but plants are winter hardy in USDA zones 9(8b) to 13, with shoots damaged by temperatures below the upper to mid-20°F, while established root systems may survive in mulched or sheltered locations in warmer parts of USDA zone 8b. Foliage: Evergreen, alternate, simple succulent leaves are up to about 2 long and more or less cylindrical or flattened oblong to narrowly oblanceolate, tapering to point; bases tend to clasp the stems; foliage is generally reminiscent of a robust coarse textured moss rose (Portulaca grandiflora); in cool weather or when plants are under stress, the foliage takes on a reddish cast, but is otherwise a strong dark green color. Flower: Small ¾diameter solitary star-shaped flowers are borne on ¼ long peduncles in the axils of the leaves; showy portions of the flowers are the white, pinkish purple to pale purple, or bicolor interior of the sepals; numerous stamens surround a single pistil; flowers occur whenever temperature conditions permit, but are small and scattered in the canopy minimizing their aesthetic contributions. Fruit: Aesthetically inconsequential small ¼ long conical capsules develop with tiny smooth shiny black seeds that are shaken out by the wind after the lid-like top of the capsule matures and is lost. Stem / Bark: Stems — stems are snaky, long, rope-like, and mostly prostrate or pendent, although some genotypes are erect for brief periods of time prior to being weighted down to the ground as they grow; stems are thickened and succulent, nearly round in cross-section and light green, green, or reddish on new stems, these typically mature to a dark green as stems age; Buds — the tiny, foliose buds do not develop bud scales; buds are usually a similar color as the stems; Bark — not applicable. Habit: Sea Purslane is an extremely rapidly growing coastal groundcover or trailing vine with sparsely set internodes that will overlap to create a dense evergreen or on the northern margins of its’ range a dieback herbaceous perennial groundcover; stems often root at the nodes; the overall texture is medium-coarse to coarse. Cultural Requirements: Culture is easy if plants are given a sunny to mostly sunny location and reasonable water availability; although very heat and wind tolerant, S. portulacastrum is only moderately drought tolerant; plants will grow on a wide range of soils; plants can be vigorous to a fault and are responsive to increased fertility. Pathological Problems: Few pest or pathogen problems appear to affect Sea Purslane. Ornamental Assets: Although the flowers are interesting, they are too small to be of much consequence; the primary aesthetic reason for planting this species is its succulent coarse textured foliage; some taxa have a stronger reddish flush than others and variable degrees of erect versus pendent foliage are present. Limitations & Liabilities: Under favorable reproductive conditions, this species can be weedy and anywhere that the vegetative tissues can overwinter there is a potential for this species to spread rapidly. Landscape Utilization: The most obvious use of this species is in coastal dune stabilization, but Sea Purslane may also serve as a fast temporary summer groundcover in colder climates; greenroofs or living walls in regions with little frost are possibilities; Sea Purslane can be grown in containers, either as a coarse textured spiller or very long trailing hanging basket plant; Sea Puslane can make an interesting curtain effect when grown hanging over walls, cutouts, or arches. Other Comments: My interest in this species vacillates widely over time; the texture and rapid growth rate are enticing, the flowers tantalizingly attractive but sparse, and then again the potential for weediness is scary; if a greater floral display could be created, this species' landscape stock could soar; the genus name derives from the old name for a Houseleek or succulent and the specific epithet refers to this species' resemblance to members of the related genus Portulaca and the Latin name for wild. Native Habitat: Nearly pantropical, including some subtropical regions such as the Texas Gulf Coast, S. portulacastrum is widely distributed; it is unclear as to this species' original native distribution due to extensive naturalization in various tropical and subtropical coastal locations around the globe. Related Taxa: The genus Sesuvium L. appears to contain about eight to ten species, although some controversy exists on these numbers; in addition to S. portulacstrum, the annual species Sesuvium maritimum (T. Walter) Britton et al. (Pharnaceum maritimum, Annual Sea Purslane, Slender Sea Purslane) and smaller statured and smaller flowered perennial Sesuvium verrucosum Raf. (Romerillo, Verrucose Sea Purslane, or Western Purslane) are also reported in Texas, but offer little interest for landscape use; Mr. Sean Carver has identified a clone derived from S. portulacastrum which fails to produce pollen that may help reduce weediness.

References: Correll and Johnston, 1979; Whitehouse, 1962.