Agave obscura aka Dark Flowered Agave

Agave obscura is an evergreen succulent in the asparagus family. It comes from central and southern Mexico, from San Luis Potosí to Oaxaca. It grows on rocky slopes and old lava flows. It also lives in pine and oak woods. Wild plants occur at 3,940–8,860 feet [1,200–2,700 metres] above sea level. Useful Tropical Plants reports its conservation status as Least Concern.

The plant forms a wide rosette with no visible stem. Garden plants reach about 3.3–4.9 feet [1–1.5 metres] tall and wide. Some accounts describe smaller plants, about 1.6 feet [0.5 metres] tall. The broad leaves range from pale green to green. Small teeth line their edges, and a sharp spine tips each leaf. The teeth may look red or grey. Plants sometimes form offsets around the base. These can grow on after the parent rosette dies.

Growth is slow, and flowers take years to appear. RHS gives a maturity range of 10–20 years. The flower stalk rises well above the leaves. Sources place it at 6.6–16.4 feet [2–5 metres] tall. Flowers crowd the upper part of the stalk. They may be dark purple, red or yellow. The fruits are oblong capsules that hold dull black seeds. The flowering rosette dies after bloom, though its offsets may survive.

Give this agave soil that drains well and a sheltered site. RHS lists sun outdoors but bright, filtered light under glass. Use cactus compost for plants grown under glass. Water moderately during growth, then keep it nearly dry through winter. RHS rates it H1C and recommends summer-only outdoor use in Britain. LLIFLE suggests dry plants may withstand about 27°F [-3°C]. It still warns against hard freezes. Pots allow plants to move into shelter when cold weather comes.

The bold rosette suits patios, courtyards and beds with Mediterranean-style planting. Its evergreen leaves provide structure through the year. It needs no pruning, but scale insects may attack it. RHS reports few disease problems. Wear gloves when handling it: the leaves can irritate skin. RHS also warns that eating it can harm cats and dogs. Useful Tropical Plants records cooked flower buds as food. This does not establish that other parts are safe to eat. The leaves also yield fibre for rope and cord. Offsets provide a way to raise new plants in spring or autumn.