Ferocactus chrysacanthus aka Golden Spined Barrel Cactus

Ferocactus chrysacanthus is a barrel cactus from northwestern Mexico. It belongs to the cactus family, Cactaceae. Its common names include golden-spined and yellow-spined barrel cactus. Kew lists its range as Cedros and West San Benito islands. These islands lie off the coast of Baja California. LLIFLE treats the West San Benito record as less certain. It also notes reports from the nearby mainland. Its habitat includes desert and dry shrubland.

The plant grows slowly and most often forms one stem. Rare clumps can have as many as six heads. The dull, grey-green stem starts round and becomes more upright. LLIFLE gives a usual upper height of 3 feet [0.9 metres]. Stem width reaches about 1 foot [0.3 metres]. Larger examples reach 3.3 feet [1 metre] tall. These can span 1.3 feet [0.4 metres] across. Between 13 and 22 ribs run along the stem. Raised bumps mark these ribs beneath the dense spines.

Each spine group has four to ten thick central spines. These twist and curve into hooks of varying strength. They reach about 0.34 feet [0.105 metres] in length. Most are golden yellow, though the species can have red spines. Four to twelve or more slender white spines surround them. These outer, radial spines reach 0.16 feet [0.05 metres] long. The thick spine cover lets the plant tolerate full sun. Its small size and golden spines give it value in cactus collections.

Flowers open in summer near the stem's centre. They can be yellow, brownish yellow, or orange. Open blooms span about 0.15–0.16 feet [0.045–0.05 metres]. Each flower measures about 0.08 feet [0.025 metres] long. Inner petals can show red stripes along their centres. Their edges may also have small teeth. Outer flower segments tend towards brown or pinkish brown. Yellow fruits reach about 0.1 feet [0.03 metres] long. They contain black seeds with a net-like surface pattern.

Its native climate combines warmth, scant rain, and fairly humid air. LLIFLE also links its habitat to a specific soil makeup. These conditions can be hard to match in cultivation. The species can therefore prove difficult to grow. Slow growth means even an older plant may stay small. LLIFLE illustrates an eighteen-year-old plant only 0.72 feet [0.22 metres] wide. That plant had already flowered for several years.