Cryptanthus bivittatus aka Earth Star

Cryptanthus bivittatus, or earth star, is an evergreen perennial bromeliad. It belongs to the pineapple family, Bromeliaceae. Its native range lies in Pernambuco, Brazil, in wet tropical habitats. It grows in soil, unlike bromeliads that live on trees. Nor does it form a tank to hold water. Gardeners grow it indoors or under glass in cooler climates.

This slow-growing plant forms a low, spreading rosette without a stem. It reaches about 0.33 feet [0.1 metres] tall. Rosettes span about 1 foot [0.3 metres], with mature spreads reaching 1.6 feet [0.5 metres]. Plants take two to five years to reach full size. Each rosette may hold 10 to 20 flat leaves. These narrow, pointed leaves have teeth and wavy edges. They measure 0.25–0.5 feet [0.08–0.15 metres] long. Stripes may show green, pink, red, ivory, or silver tones. The bright leaves provide most of the plant's visual interest.

Small, tubular flowers appear at the centre of the rosette. They may be white or pink and bloom in spring or summer. A plant may take years to flower. Each rosette flowers once, then slowly dies as side shoots grow. These shoots, called pups, allow the clump to persist. Gardeners can separate pups once they reach one-third of the parent's size. Seeds offer another means of propagation.

Give earth star bright, filtered light and moderate to high humidity. Deep shade can dull the leaf colours. Strong midday sun can bleach and shrivel the leaves. Use acidic, humus-rich soil that drains well, or terrestrial bromeliad compost. Water the root zone when the soil surface feels dry. Water moderately during growth and reduce watering in winter. Apply dilute liquid feed monthly during active growth. The RHS rates it H1A, for warm indoor or glasshouse conditions above 15°C. NC State lists USDA zones 8–11, but also calls it frost tender.

Earth star suits pots, terrariums, bottle gardens, and conservatories. In tropical gardens, its spreading clumps can serve as ground cover. Its striped leaves also suit grouped plantings and sheltered borders. It needs no pruning and has few routine problems. Mealybugs, scale insects, and mites can still attack it. Root rot is another risk. NC State identifies it as non-toxic to cats and dogs. The supplied sources give no edible uses or human safety assessment.