Eve sent me this picture of her lovely bromeliad flower. Actually, it’s not a flower; it’s a whole group of flowers. The pink, slightly spiky structures are bracts, and the actual flower buds are the dainty lilac tipped items peeking out from amongst the bracts. The flower head persists for months as the individual flowers develop from the base to the tip.

It got me thinking about the bromeliad family (Bromeliaceae) and the way that we usually just lump them together. “It’s a bromeliad,” we say, without ever seeking further identification. But the bromeliads are a huge family (about 3600 species) and range from types that thrive in the hot wet Amazon jungle, such as many Vriesia species, through to extremely drought adapted dessert species such as Puya berteroniana.

Most of the forms that are useful in our gardens are those that have a mechanism for coping with periods of dryness, as in our summers. Some have developed trichomes  fine, dense hairs or scales covering the leaves. These are used by cloud forest bromeliads to collect water from humid air, and in desert species the silvery colour of the trichomes reflects sunlight. Other species, often referred to as ‘tank’ bromeliads, have a tightly encircling rosette of leaves holding a central tank or reservoir of water. Bromeliads also use crassulacean acid metabolism (CAM) to cope with hot dry conditions. This is a metabolic pathway that enables them to use stored carbon dioxide for photosynthesis, instead of having to open their stomata (leaf pores) to take in CO₂ from the atmosphere and so also loose water through these pores.

Some Bromeliads that do well in dry shade include the genera:

Aechmea

Eve’s lovely bromeliad is an urn plant (Aechmia faciata). Aechmeas are tank plants. The flower head is produced in spring or autumn and persists for many months, but after flowering, the plant dies. It leaves pups (suckers) that grow into the next generation of plants. Another popular species is matchstick plant (A. gamosepala). This plant has a rosette of strappy green leaves, and produces flower heads that look like columns of rather surreal pink and blue matches.

Ananas

Edible pinapple (A. comosus) belongs to this genus, and red pineapple (A. bracteatus) has a rosette of toothed leaves (often variegated) that bear a red inflorescence that gives rise to a small red pineapple- shaped fruit. The plant can be grown from full sun to full shade, but must have very good drainage, or will suffer from root rot. It prefers acid soils so is best grown in pots in Strandveld.

Billbergia

Billbergias are tank plants with a rosette of (usually) narrow strappy leaves that are often brightly coloured. Their flowers are often produced on long arching or drooping stems. One of the most popular garden species is B. nutans (Queen’s Tears). The plant is an epiphyte in the wild, but can grow in the ground provided the site is free-draining. It has somewhat grass-like silvery-green leaves, and dainty flowers produced on drooping stems, in spring. It grows best in partial shade. Another popular species is B. pyramidalis, with a flower head that is shaped more like an Aechmea.

Neoregelia

Neoregelias are also tank plants. They often have broadly strappy brightly coloured leaf rosettes, The central leaves are frequently pink, purple or red. The flowers are produced in a flower head that just peeps out of the central reservoir or tank. The flowers are often violet. Neoregelia ‘Scarlet Charlotte’.is a popular hybrid, that grows in dry shade on well-drained soil.

Tillandsia

Tillandsias are mostly air plants that hang in trees, collecting all the moisture and nutrients they need from the air. To help in this, they have silvery-grey leaves covered in trichomes. Their flowers are usually pink and blue or red. Two of the commonest species in gardens are T. aeranthos and T. bergeri. Although they collect moisture and food from the air, they can benefit from occasional soaking in a bucket of water with a little dilute plant food in it. Mist spraying in dry weather also keeps them healthy. They prefer semi-shade, but can grow in full sun, especially if they are misted more frequently. Another popular species is Spanish moss (T. usenoides). This has very fine silvery foliage that hangs down from branches, looking more like some sort of lichen than like moss. The tiny green flowers are inconspicuous, but have a pleasant smell.