Warming's Lepismium

About

Warming’s lepismium is a trailing jungle cactus with narrow, ribbon-like stems. Its stems are thin and jointed, three or four-angled or nearly flat, with softly scalloped edges. They are fresh green, often colouring purple or bronze in brighter light, and they can trail from a pot to a metre or more. The stems are fine and spineless, so the plant works well in a hanging pot.

It is an epiphyte from the humid forests of south-east Brazil and nearby, where it grows on branches and shaded rock. Filtered light and even moisture suit it better than harsh sun and drought. It sits in the same broad group as the pendent, prickly rat’s tail cactus and the club-jointed dancing bones, and takes similar care, though its stems are softer and less showy.

Along the notched rims of its stems it opens small, pale flowers, white to pink, through the cooler months, sometimes followed by little berries. It is forgiving, soft and quick to root. It needs filtered light, an open mix and a cool, drier rest in winter to flower.

Appearance and character

The stems are long and slender, jointed and angular, three or four-sided to almost flat, their margins gently notched, and they shift from fresh green to a purple or bronze cast where the light is strong.

They branch and trail freely over the pot’s edge to a metre or more, and they are soft and unarmed, so the plant is easy to handle and place, unlike the spiny rat’s tail.

Fresh segments push from the notches and stem tips, so the plant fills out as well as lengthening, eventually making a dense trail of fine stems.

Its flowers are small and pale, white to pink, set along the scalloped edges of the stems in the cooler months, and sometimes followed by small berries.

Where it is from

Lepismium warmingianum lives in the humid forests of south-east Brazil and adjoining parts of South America, perched as an epiphyte on tree limbs and shaded, mossy rock in broken, filtered light, its roots in leaf litter. It belongs to the forest canopy instead of the ground.

That forest habitat explains its care. Filtered light, an open and airy root run, and steady, modest moisture suit it, with a cooler, drier winter to bring on its flowers. A cold, wet pot rots it, and direct midday sun burns its soft stems.

How it grows

It grows through spring and summer, branching and lengthening its trailing stems, then settles into a cooler, drier winter rest, which helps set buds. Warmth, filtered light and steady watering keep it growing.

Pot it in a loose, quick-draining epiphytic mix in a hanging or raised pot where the stems can fall, and water once the surface has dried, keeping it evenly but modestly moist while it grows. It should drain freely each time.

Keep it in humid air and in bright, filtered light, warm through the growing months and cooler and drier for its winter rest, never below about 7 deg C. Shield it from the direct midday sun that scorches the stems, and from chilling draughts.

To make more, take a length of stem as a cutting, leave the cut end to dry for a day, and set it into a gritty, open mix. It roots quickly.

Through the seasons

Spring starts strong growth. Increase watering and feeding as the stems lengthen.

Summer carries the main growth. Keep it in bright, filtered light, evenly but modestly moist, and feed each month, shading it from direct sun.

Autumn slows it as the light drops. Taper the feeding and watering, and begin the cooler, drier rest.

Winter is a cool, drier rest above about 7 deg C, when the small flowers may show. Water it sparingly, and keep it cool instead of warm.

Care difficulty

Easy, and among the most forgiving trailing jungle cacti. It grows readily, roots from stem cuttings, and only needs filtered light, a loose mix and steady, modest watering. It suffers in a cold, wet pot, which rots it, and in direct sun, which scorches it. Its soft, spineless stems make it a good hanging plant for a beginner.

Watering

Water once the top of the open mix has dried, keeping the plant evenly but modestly moist through spring and summer. Being a forest cactus it likes steadier moisture than a desert one, though the mix must clear freely and never stay waterlogged.

Through the cool winter rest, water only lightly, which suits the dormancy and helps the buds set. Tip out any water that collects under a hanging pot, since stems left cold and wet will rot.

Warning signs, diseases and pests

A cold, wet pot rots the stems and roots, showing as soft, sallow or blackened stems over a mushy base. Move it to an airier mix, water it less, warm it up, and root sound stems if the base has gone.

Direct summer sun scorches the soft stems, leaving pale patches. Shift it into bright but filtered light, and the new growth should be healthy.

Mealybugs lodge along the stems and in the notches as white fluff. Wipe them off with dilute alcohol, and check often, since the trailing stems give them cover.

Growing environment

Bright, filtered light suits it, matching the broken light of its forest home. Direct midday sun burns the stems, and deep shade thins the growth and stops it flowering, so aim for brightness without glare.

It likes warmth in the growing months and a cooler, drier winter rest, staying above about 7 deg C, in air on the humid side. Cold draughts and the parching heat of a nearby radiator both do it harm.

Plant it in a loose, sharply draining epiphytic mix in a hanging or raised pot that lets the stems trail, and site it somewhere bright, out of direct glare, and humid.

Feeding

Over spring and summer, a weak balanced or high-potassium feed once a month keeps the stems growing and the flowers coming. Taper it off through autumn, and give none while the plant rests in winter.

Every so often, pour plain water through the pot to wash out any fertiliser salts. There is no need to feed a recently repotted plant for its first several weeks.

Troubleshooting

The stems have pale, bleached patches. Scorch from direct summer sun. Move it into bright but filtered light, and the new growth should be healthy.

The stems have gone soft and yellow. Rot from a cold, wet pot. Move it to an airier mix, water less, warm it up, and root healthy stems if the base has failed.

It hardly flowers. Usually a winter too warm or too dark. Give it a cooler, drier winter in bright filtered light and a high-potassium feed.

How is it different from the rat’s tail cactus? Its stems are thin, angular, notched and spineless with small pale flowers, where the rat’s tail cactus has round, bristly stems and vivid pink flowers. Both are trailing jungle cacti grown the same way.

Is it safe around pets? Yes. Lepismium carries no listed toxin, and its stems are soft and spineless, so it is safe with cats and dogs.