What's in Bloom

Queen's tears (Billbergia nutans) is one of the easier of the epiphytic bromeliads for homeowners to grow and flower. The pink and violet-blue flowers are surrounded by rose-pink bracts on long arching racemes. Like other bromeliads, the leaves form a watertight rosette that allows the species to survive periodic droughts. This species produces copious quantities of buds at the base of the cup that grow to about 18 inches in length, and then produce another cup. Billbergia nutans is native to a wide swath of South America, from southern Brazil to northern Argentina.

In the home landscape, provide as much light as possible and add water to the cup once a week. For best results, use rainwater to avoid the leaf scorch associated with fluorinated and/or chlorinated water. In the wild the cups host a biological microcosm of single-celled organisms, algae, and small amphibians. If mosquitos or fungus gnats take up residence, treat with Bacillus thuringiensis var. israelensis — a bacterial disease of mosquito larvae, fungus gnat, and blackfly larvae that is available in most nurseries or garden departments.

Queen's tears (Billbergia nutans) is in the Tropical Greenhouse.

The red spike ice plant (Cephalophyllum alstonii) produces vibrant red flowers held just above the thick, fleshy, triangular leaves. A native of the Ceres Karoo in South Africa, this plant does not tolerate frost or excessive moisture. The seeds (nutlets) are held in the fruiting capsule until the next rainfall event, during which they are forcibly ejected.

Red spike ice plant (Cephalophyllum alstonii) is in the Arid Greenhouse.

Pachypodium of Madagascar (Pachypodium decaryi) is currently covered with 4-inch, heavily textured white flowers held in clusters at the ends of long, fleshy stems. Not particularly fragrant, the color suggests a moth or bat may be the pollinator. Unlike other pachypodiums, the stems of Pachypodium decaryi are not armed with spines. It is among the rarest of its species, due to difficulties with propagation.

"Pachypodium" translates into "elephant foot," in reference to the thickened lower trunks used to store up water for the prolonged droughts of its homeland. It is native to the island of Madagascar — one of the world's most threatened biological hotspots, due to conversion of the natural ecosystems into agricultural land to support a growing population.

Pachypodium of Madagascar (Pachypodium decaryi) is in the Arid Greenhouse.

The dwarf pomegranate (Punica granatum 'Nana') produces masses of bright orange flowers on a glossy-leaved deciduous shrub that rarely exceeds 2.5 feet in height. Best grown in full sun with moderate fertilization, this dwarf cultivar is grown almost exclusively as a landscape plant, and can produce an attractive fall color. Fruit is rarely produced, and never matches the flavor of the larger cultivars.

Pliny was well acquainted with this plant; pomegranates are native to an area stretching from the eastern Mediterranean to the Himalayan Mountains. Many cultivars have been selected for their fruit characteristics, and these are reproduced through vegetative propagation, because the cultivars do not come true from seed. Pomegranates prefer moist, well-drained soils in regions featuring long, hot, dry summers. The area around Kandahar, Afghanistan, is famous for its groves of pomegranates.

Dwarf pomegranate (Punica granatum 'Nana') is in the Subtropical Greenhouse.