Agave horrida

Agave horrida is a spectacular species due to the geometric regularity of its large rosette. Its leaves are densely imbricated, forming a ball as wide as it is tall, rarely exceeding 1m (3ft) in adulthood. The dark green leaves are armed with light grey spines along their edges, giving the plant a somewhat fierce appearance, which is highly appreciated by enthusiasts of the genus. Being a lover of sun and heat, this species will grow in warm climates. However, it is quite hardy so it can also grow in colder regions. It will thrive in most poor and well-drained soils and can potentially be grown in large containers to be brought indoors during winter in excessively cold climates. 

Agaves belong to the Asparagaceae family (formerly Agavaceae), which comprises over 600 species and about 20 genera, many of which are ornamental (Yucca, Cordyline, Sansevieria, Nolin). Native to Mexico, Agave horrida grows naturally in two specific regions: the state of Morelos in the country's centre, and the coastal state of Veracruz to the east. Two very similar forms are distinguished: Agave horrida horrida (Morelos) and Agave horrida perotensis (Veracruz), with slightly narrower leaves and a more open habit due to the peripheral leaves descending towards the ground and spreading out.

Agave horrida is characterised by its very dense rosette, which has a perfect geometric shape. Its elongated leaves, lanceolate and pointed at their tips, slightly widen in the middle. Concave in section, they stand upright towards the sky and gradually lean outward as new leaves appear, eventually forming a perfect ball as wide as it is tall. It grows relatively fast compared to other species, and over time, it forms specimens of 80cm (32in) to 1m (3ft) in diameter, rarely more. When young, the leaves are a slightly glossy medium green, but they turn into a darker, more matte green as they age. Sometimes, a slightly lighter longitudinal band can be observed along the leaves.

Spines adorn the entire perimeter of the leaf, reminiscent of shark teeth. They start off brown-red or occasionally black, and as they age, they turn light grey, almost white. These spines can be straight, curved, or even undulate, but always in the same plane as the leaf. While they can be formidable for hands, they greatly contribute to the plant's aesthetic appeal.

Unlike other species in the genus, this agave generally does not produce offsets at the base. This makes it easier to grow in containers in regions with cold winters (though attention should be paid to the weight of the plant, as it can become heavy over time). Grown in well-drained conditions, Agave horrida can withstand temperatures down to -10 to -12°C (14 to 10.4°F), which allows it to acclimatise beyond the Mediterranean region. It accepts any well-drained soil, from acidic to calcareous, including sandy and poor soils. 

This perfectly patterned Agave horrida will create a dry garden with an exotic look. A south-facing slope, with soil enriched with sand and gravel to improve drainage, will aid its cultivation. Indeed, it is more often humidity and stagnant water that prove fatal to this type of plant. Choose complementary plants to create a stunning scene: Opuntia engelmannii, with its large pads, is one of those hardy cacti that quickly create a unique ambiance, with each new pad producing new shoots every year. The ephemeral yellow flowers are magnificent and subsequently give way to highly decorative red fruits. Yucca rostrata, with its perfect shape and long, tapered leaves of varying shades of blue, is also well-suited for this type of setting.

Agave is also an edible plant, from which the alcoholic beverage mescal is made in Mexico through the fermentation of its sugar-rich juice. It is also used in traditional medicine in Mexico, Brazil, and India, as it has proven antifungal properties.