Senna occidentalis

Senna occidentalis

The Coffeeweed (Senna occidentalis L. Link, 1829) is a shrub species belonging to the Fabaceae family.

Systematics –
From the systematic point of view it belongs to the Eukaryota Domain, Kingdom Plantae, Magnoliophyta Division, Magnoliopsida Class, Fabales Order, Fabaceae Family, Caesalpinioideae Subfamily and therefore to the Genus Senna and to the S. occidentalis Species.
The terms are synonymous:
– Cassia caroliniana Walter;
– Cassia ciliata Raf .;
– Cassia falcata L .;
– Cassia foetida Pers .;
– Cassia laevigata sensu auct .;
– Cassia macradenia Collad .;
– Cassia obliquifolia Schrank;
– Cassia occidentalis L .;
– Cassia occidentalis (L.) Rose;
– Senna occidentalis (L.) Roxb .;
– Cassia planisiliqua L .;
– Cassia planisiliqua Burm. f .;
– Cassia plumieri DC .;
– Ditramexa occidentalis Britton & Rose;
– Ditremexa occidentalis (L.) Britton & Wilson;

Etymology –
The word Senna comes from the Arabic word sanà, a vernacular name given to Senna spectabilis.
The specific western occidentalis epithet refers to the distribution area.

Geographic Distribution and Habitat –
Senna occidentalis is a pantropical plant species and therefore grows in all tropical regions.

Description –
Coffeeweed is an annual, sub-glabrous, fetid shrub, a few feet tall.
The leaves are alternate, compound, paripinnate.
The rachis is canalized, with the presence of a gland at the base of the rachis; stipules obliquely cordate, sharp; the leaflets are 4-5 pairs with dimensions of 3.7 cm X 2 cm and 7 cm X 3.5 cm), with obate to oblong-lanceolate conformation; acuminate, with ciliated, glabrous or pubescent margin.
The inflorescence is an axillary corymb with terminal panicle.
The flowers are complete, bisexual, slightly irregular, zygomorphic, pentamer, hypogenous, pedunculated; bracts white with pinkish hues, thin, ovate-sharp, deciduous, yellow in color. The calyx has 5 sepals, gamosepals, with short tube, 5 lobed, obtuse, glabrous, imbricate, the odd sepal is anterior. The corolla has 5 petals, polypetal, alternisepal, subequal, with distinct claws, conspicuously veined, ascending imbricate, with the posterior petal being the innermost.
The androecium has 10 stamens, free, of unequal size, 7 perfect and 3 reduced to staminodes, unequal filaments, anther ditica, basifissa, introrse and dehiscent due to terminal pores.
The gynoecium is monocarpellar with superior ovary, unilocular, many ovules, marginal placentations; simple stylus; the stigma ends up happening.
The fruit is a pod, dehiscent, woody, 12.5 cm X 0.7 cm, hairless, curved, sub-compressed, distinctly torulous, with the presence of 23-30 seeds inside.

Cultivation –
Senna occidentalis is a plant that grows spontaneously but can be grown in sunny areas sheltered from the winds. It also bears temperatures a few degrees below zero.
It prefers loose soils, mixed with peat and sand, rich in organic matter and well drained.
The specimens raised in the ground are generally satisfied with rain water and should be watered only during periods of prolonged drought; those grown in pots require abundant water supplies especially during the vegetative period and in summer.

Customs and Traditions –
The Senna occidentalis is called by the vernacular names: ‘au’auko’i in Hawaii, septicweed, Senna coffee, coffeeweed, Mogdad coffee, negro-coffee, Stephanie coffee, stinkingweed. The plant is also locally called Bana Chakunda in Odisha, India.
The plant is said to be poisonous to livestock. The plant contains anthraquinones. The roots contain emodin and the seeds contain chrysarobin (1,8-dihydroxy-3-methyl-9-anthron) and N-methylmorpholine.
In Jamaica, the seeds are roasted, prepared and served as a tea to treat hemorrhoids, gout, rheumatism and diabetes.
This plant is used in India mainly for the treatment of bone fractures and bone dislocation as a herbal treatment.
Furthermore, also in India, almost all parts (leaf, root, seeds) of the plant are used as food and medicine by the tribal populations. However, consumption of Bana Chakunda seeds has been identified as a possible cause of death of tribal children due, as a cause, to acute encephalopathy (see Acute HME Syndrome). In fact, when the plant was identified as the cause, the number of deaths decreased rapidly.
The same thing occurred in Rio Grande do Sul, Brazil, where 16 outbreaks were recorded. This was a record compared to the 1979 clinical study, in which eight calves died after contracting dyspnoea, neutrophilia and tachycardia from eating the plant.

Preparation Method –
Despite claims of their poisonousness, the leaves of this plant, Dhiguthiyara in the Maldivian language, have been used in the Maldivian diet for centuries in dishes such as mas huni and also as a medicinal plant.
Mogdad coffee seeds can be roasted and used as a coffee substitute. They have also been used as an adulterant for coffee.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Conti F., Abbate G., Alessandrini A., Blasi C. (edited by), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.

Warning: Pharmaceutical applications and alimurgic uses are indicated for informational purposes only, they do not represent in any way a medical prescription; therefore no responsibility is taken for their use for curative, aesthetic or food purposes.