Desmanthus bicornutus

Desmanthus bicornutus is a species of flowering plant in the legume family native to northern and central Mexico and the southwestern United States.[2][3][4] It is an "abundant roadside weed across its native range."[5] It is known by the common names ruby bundleflower,[2] two-horn bundleflower,[3] and in Mexican Spanish malvilla de laguna.[5]

Desmanthus bicornutus
Conservation status
Apparently Secure  (NatureServe)
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Fabales
Family:	Fabaceae
Subfamily:	Caesalpinioideae[1]
(unranked):	Mimosoid clade[1]
Genus:	Desmanthus
Species:	D. bicornutus
Binomial name
Desmanthus bicornutus S.Watson

In Queensland

Description

A small, upright-standing shrub that grows to about 3 meters in height, Desmanthus bicornutus has a woody base. Young stems are often a deep red color; older stems are shiny red or brown. The compound bipinnate leaves are between 9 cm and 18 cm long.

Desmanthus bicornutus blooms in condensed spikes of 25-60 flowers. These flowers may be perfect (occurring apically), functionally male (occurring towards the base of the flower head above the sterile flowers but below the perfect flowers), or sterile. It bears up to a dozen edible linear pods on fruiting stalks up to 5 cm long. Pods are up to 10 cm long and 5.5 mm wide. Immature pods are red but these turn to a dark brown as they mature.[5]

Distribution

Desmanthus bicornutus grows in the states of Baja California Sur, Chihuahua, Sinaloa, and Sonora in Northern Mexico as well as the central states of Colima, Guerrero, Jalisco, Michoacán, Nayarit, and Veracruz.[5] In the United States, D. bicornutus grows naturally only in the state of Arizona.[2]

Ecology

This plant favors clay, rocky, or sandy soils in its native range. At higher elevations, D. bicornutus can be found amid oak forest and in grasslands. At lower elevations, this plant is found near canyons, roads, and waterways.[5]

Though occurring over an area with a wide annual rainfall range (from 300 mm in Arizona to up to 2,000 mm in coastal, southeast Mexico), D. bicornutus is found in areas with intense dry seasons of up to ten months duration.[5] This species typically dies back to its base during winter or dry season and refoliates when conditions become favorable again.[6] It will also regrow in environments ravaged by wildfire.[5]

Use

In Guerrero, Mexico, D. bicornutus beans are used in the making of salsa.[5]

As a component of grasslands in northern Mexico and southern Arizona, D. bicornutus benefits the grazing of livestock and is tolerant of defoliation caused by heavy grazing.[5]

D. bicornutus has been grown experimentally in Australia. Although it grows abundantly as a weed in its native area and may be a potential invasive species, 14-year-old experimental plots of D. bicornutus in western Queensland have not overgrown their boundaries.[5] A few cultivars of D. bicornutus have been developed by Texas A&M University.[6][7]

References

1. The Legume Phylogeny Working Group (LPWG). (2017). "A new subfamily classification of the Leguminosae based on a taxonomically comprehensive phylogeny". Taxon. 66 (1): 44–77. doi:10.12705/661.3.
2. Archived 2007-12-13 at the Wayback Machine Arizona Game and Fish Department. 1991. Desmanthus bicornutus. Unpublished abstract compiled and edited by the Heritage Data Management System, Arizona Game and Fish Department, Phoenix, AZ. 3 pp.
3. USDA natural Resources Conservation Service
4. Texas A&M University Department of Biology Herbarium
5. Tropical Forages
6. Published in Crop Sci. 44:1859–1860 (2004).
7. Archived 2010-06-12 at the Wayback Machine "New Forage Varieties for the Southeast" (Proc. 58th Southern Pasture and Forage Crop Improvement Conference, Roanoke, VA June 13, 2004)

Further reading

• Gardiner C.P. and Burt R.L. (1995). Performance characteristics of Desmanthus virgatus in two contrasting tropical environments. Tropical Grasslands, 29, 183-187.
• Hopkinson, J.M. and English, B.H. (2004). Germination and hardseededness in Desmanthus. Tropical Grasslands, 38, 1-16.
• Luckow, M. (1993). Monograph of Desmanthus (Leguminosae-Mimosoideae). Systematic Botany Monographs. Vol. 38. The American Society of Plant Taxonomists.
• Ocumpaugh, W.R., et al. (2004). Registration of "BeeTam 06". Crop Science, 44.
• Pengelly, B.C. and Liu, C.J. (2001) Genetic relationships and variation in the tropical mimosoid legume Desmanthus assessed by random amplified polymorphic DNA. Genetic Resources and Crop Evolution, 48, 91-99.