The genus Agave is treated here in a wide sense to include taxa previously treated as belonging to the genera Manfreda, Prochnyanthes, Polianthes and Pseudobravoa. Not all botanists are happy with this treatment, with some feeling that these genera should remain distinct, at least until further studies have been carried out. In addition, given the high species diversity found in Agave, some feel that an alternative approach could be the recognition of several smaller genera within the current circumscription of Agave[
Agave dentiens Trel.
Agave nelsonii Trel.
Agave cerulata is an evergreen, stemless, succulent plant forming a rosette of leaves that can be 25 - 50cm tall and 40 - 75cm in diameter. The leaves on mature plants can each be 25 - 50cm long and 4 - 7cm wide near the base. After several years of growth, a flowering stem that can be around 2 - 3.5 metres tall is produced, after which the rosette will die. However, the plant usually suckers freely and the young rosettes will develop as new plants[
The plant is harvested from the wild for local use as a food and a drink.
Although some of the subpopulations of Agave cerulata have considerable mining threats, the population as a whole is stable and the extent of occurrence of this species is wide It is relatively abundant and occurs in several protected areas. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2019)[
Many Agave species have strong, sharp spines on the leaves and leaf tips.
In theory at least, the flowers, nectar, immature flowering stem and the centre of the rosette of all Agave species is edible and, with proper preparation, can provide a sweet, tasty foodstuff. Some species, however, contain relatively high levels of saponins (which makes them taste bitter) and some other compounds which can cause bellyache, and so these would only be eaten in times of desperation. In addition, many people may find these foods to be strongly laxative the first few times they eat them[
Southwest N. America - northwest Mexico (Baja California)
Sarcocaulescent scrub and xerophyllous scrub on volcanic soils.; at elevations from sea level to 1,500 metres[
Agave cerulata is native to a very arid region of southwest N. America, where the mean annual rainfall can be just 90 - 250mm. However, it is generally found in an upland maritime environment where frequent fogs and ocean breezes temper the desert climate[
Agave species generally require a sunny position, succeeding in most soils of medium-fertility so long as they are very well-drained. Most species are undemanding as to the soil pH, though those found in the wild on limestone soils will grow better in neutral to alkaline conditions. An extremely drought-tolerant species, it can survive several years with little or no rainfall[
Most Agave species are monocarpic, individual rosettes living for a number of years without flowering before sending up an often very large flowering stem and then dying after flowering and setting seed. This species, however, usually suckers freely to produce many new rosettes during its lifespan and these new plants will continue to grow after the death of the parent plant[
]. Over time, some species can form extensive clonal colonies by this means.
Individual plants take about 7 - 15 years in their native habitat, considerably longer in colder climates, before flowering[
Members of this genus are rarely if ever troubled by browsing deer[
The plant is used for food[
There is a relatively high content of sapogenins in the plant (averaging more than 0.9% over the year) which would make the hearts of the plant, leaves etc somewhat bitter. Nevertheless, the plant was often used for food by the native peoples[
]. The subspecies dentiens seems to have been especially favoured[
The juice of cooked then macerated leaves was drunk to relieve thirst[1845.. The juice was also allowed to ferment in warm water for several days to make a mildly alcoholic beverage[
The plant is used to make 'mezcal'[
]. (refers to subspecies dentiens) Mezcal is a distilled alcoholic beverage that potentially can be made from almost any species of Agave, though only around fifty are used regularly and seven species are especially favoured. Mature plants are harvested from the wild, their leaves and roots are removed and the remaining 'hearts' are baked (often in an earth oven), then mashed and the resulting liquid allowed to ferment for a few days before being distilled to produce mezcal.
The plant contains relatively high amounts of sapogenins (an average of almost 1% in the leaves, but rising to 1.5% in December)[
]. Various sapogenins are of value to the pharmaceutical indistry as the precursors of various hormones, cortisone etc[
Seed - surface sow in a light position, mid spring in a warm greenhouse. The seed usually germinates in 1 - 3 months at 15 - 20°c[
]. Prick out the seedlings into individual pots of well-drained soil when they are large enough to handle and grow them on in a sunny position in the greenhouse until they are at least 15cm tall. Plant out at the beginning of the growing season, and give some protection from the cold for at least their first few winters[
Offsets and suckers can be potted up at any time they are available. Keep in a warm greenhouse until they are well established[
Bulbils, where produced, are an easy method of propagation. Simply pot them up and plant out at the beginning of a growing season when they are 10cm or more tall.