Espostoopsis dybowskii aka Cabega

Espostoopsis dybowskii, also called Cabega, is a cactus from Bahia, Brazil. It is the sole species in its genus. Its range includes the Rio de Contas valley and northern Bahia. It grows in caatinga, a region with a seasonal dry spell. Plants live on granite, gneiss, and quartzite rock outcrops. They can form dense stands that are hard to cross. Farming, cattle ranching, mining, fires, and urban growth threaten wild plants.

This shrubby cactus branches near the base into several upright stems. It reaches about 6.6–13.1 feet [2–4 metres] tall. Each stem forms a round column with 20–28 low ribs. Thick white hairs hide much of the stem surface. The areoles bear yellowish wool as well as white hairs. Each has two or three sharp central spines. These spines range from yellow to brown. Many fine radial spines lie hidden among the hairs.

Flowers open at night from a woolly zone called a cephalium. This zone runs along one side of the stem. It can reach about 2 feet [0.6 metres] long. The white blooms have short tubes that widen into bells. Tiny scales mark their otherwise bare flower tubes. The pale pink fruit has a broad, egg-like shape. It holds white pulp inside a thick outer wall. The fruit stays closed rather than splitting when ripe. Old flower parts remain attached and turn black. The black seeds have rough surfaces and oval or pear-like shapes.

This tropical cactus needs care and is not a beginner's plant. It can grow fast when conditions suit it. Give it very bright light and a porous cactus mix. Strong light can cause bronzing and promote blooms and spines. Its weak roots need a pot that drains well. Repotting can set it back, with a long recovery. During growth, let the mix dry well between waterings. Yet do not leave it dry for long periods. Too much water can cause rot.

Warmth throughout the year helps this cold-sensitive species survive. Keep temperatures above 8–12°C rather than testing its brief cold tolerance. It rests from October to April but still needs some water. The source suggests watering about once a month during rest. Do not feed it in winter. Raise new plants from seed in a light, sandy mix. Keep germinating seeds from drying out, at 18–22°C.