Senegalia berlandieri Seeds | (acacia )
LATIN NAME: Senegalia berlandieri
COMMON NAME: Guajillo
Plant Profile
Guajillo is a feathery shrub of the dry brush country of southern Texas and northeastern Mexico, where it grows on limestone and caliche beside mesquite and acacia. It reaches one and a half to three metres, with many slender, arching branches, twice-divided leaves of tiny leaflets and small, creamy-white, fluffy flower heads that open in spring. The whole plant has a soft, open, fern-like look that belies its toughness: it is one of the most drought-tolerant shrubs of the region, and it stays green through months without rain. The flowers are a famous honey source, and guajillo honey, pale and delicate, is one of the most prized in North America. The plant is thornless or nearly so, unlike most of its neighbours.
Science & Biotechnology
Senegalia berlandieri was long placed in Acacia, and the split of that enormous genus in 2005 moved it, along with most New World species, into Senegalia, a change based on molecular phylogeny and on characters of the pollen and the extrafloral nectaries. The species is a tetraploid and hybridises with related Senegalia where their ranges overlap, which complicates identification in the field. Its leaves fold at night and in drought, a nyctinastic response that reduces water loss, and its roots go deep enough to reach moisture that shallow-rooted shrubs cannot use. The nectar flow is unusually concentrated: a single bush in full flower can supply a colony for days, and beekeepers in Texas move hives to follow the guajillo bloom. Seed set varies enormously between years, which is typical of desert legumes.
Uses & Benefits
The plant is primarily a honey and browse species. Its flowers give one of the finest honeys of the American Southwest, light amber with a mild, buttery flavour, and its foliage is browsed by deer, goats and cattle in a region where green feed is scarce. It is also planted in xeriscapes and wildlife gardens, where its fine texture and spring flowers work well against coarser desert shrubs. The wood is small and not commercial, and the seeds are not eaten by people. For a dry garden it is a useful mid-height shrub that needs no irrigation once established, and its flowers attract a wide range of native bees as well as honeybees. It fixes nitrogen, so it improves poor soil around it.
Growing from Seed
Scarify the seed by nicking the coat with a file or soaking in hot water for a minute, then soak overnight. Sow in a gritty mix of sand, loam and perlite, one centimetre deep, and keep at twenty-five degrees. Germination is fast, usually within two weeks. The seedling has a long taproot and should be grown in a deep tube from the start. Water sparingly after the first month, and plant out into sharp-draining, alkaline soil in full sun. It tolerates reflected heat and poor ground but not wet feet. Prune lightly after flowering to keep it dense, and do not feed, which makes it soft and short-lived. Flowers appear in the second or third spring.
Our Take
A thornless desert shrub with ferny leaves and some of the best honey in North America. Dry, alkaline and sunny.
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