''Isoglossa woodii'', commonly known as buckweed, is a

monocarpic Monocarpic plants are those that flower and set seeds only once, and then die. The term is derived from Greek (''mono'', "single" + ''karpos'', "fruit" or "grain"), and was first used by Alphonse de Candolle. Other terms with the same meaning are ...

shrub of the family

Acanthaceae Acanthaceae is a family (the acanthus family) of dicotyledonous flowering plants containing almost 250 genera and about 2500 species. Most are tropical herbs, shrubs, or twining vines; some are epiphytes. Only a few species are distributed in te ...

, growing up to 4 m tall. It grows in colonies in coastal forest areas of

KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN and known as "the garden province") is a province of South Africa that was created in 1994 when the Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu) and Natal Province were merged. It is locate ...

and marginally into

Eastern Cape The Eastern Cape is one of the provinces of South Africa. Its capital is Bhisho, but its two largest cities are East London and Gqeberha. The second largest province in the country (at 168,966 km2) after Northern Cape, it was formed in ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

Description

The stem is often multi branched and sparsely hairy, with lower stems becoming woody. The leaves are between 75 mm and 120 mm long, and are soft and often droop during dry conditions. The leaves have a velvety texture due to fine, dense hairs on the surface. These plants have a life cycle of about 7 to 10 years, after which they flower ''en masse'' and then die off. The flowers are produced in inflorescences and individual flowers are whitish in colour and about 8 mm in length.

Ecological significance

These plants form dense colonies in the understorey of forests where they provide food and shelter to many animals.

Blue duiker The blue duiker (''Philantomba monticola'') is a small antelope found in central, southern and eastern Africa. It is the smallest duiker. The species was first described by Swedish naturalist Carl Peter Thunberg in 1789. 12 subspecies are ident ...

and

bushbuck The Cape bushbuck (''Tragelaphus sylvaticus'') is a common and a widespread species of antelope in sub-Saharan Africa.Wronski T, Moodley Y. (2009)Bushbuck, harnessed antelope or both? ''Gnusletter'', 28(1):18-19. Bushbuck are found in a wide ra ...

feed on the leaves and shoots. The flowers attract many species of insects, and honey is said to be plentiful in years when these plants flower. Buckweed is excluded from areas of forest with dense tree cover and in turn plays a role in limiting forest regeneration as the tree seedling community beneath ''Isoglossa woodii'' shows reduced density and species richness from areas where ''I. woodii'' is absent. Butterfly larvae of ''

Protogoniomorpha parhassus ''Protogoniomorpha parhassus'', the forest mother-of-pearl or common mother-of-pearl,Williams, M. (1994). ''Butterflies of Southern Africa; A Field Guide''. . is a species of Nymphalidae butterfly found in forested areas of Africa. Subspecies *' ...

'' and ''

Celaenorrhinus mokeezi ''Celaenorrhinus'' is a genus of skipper butterflies which are commonly termed sprites. An alternate name is flats, for their habit of holding their wings flat when resting, but this is also used for related genera. They belong to the spread-win ...

'' are known to feed on the leaves of ''Isoglossa''.

Etymology

This plant was named after

John Medley Wood John Medley Wood (1 December 1827 Mansfield, Nottinghamshire, England – 26 August 1915 Durban) was a South African botanist who contributed greatly to the knowledge of Natal ferns, is generally credited with the establishment of sugarcane mosa ...

(hence ''woodii''). The common name of buckweed is a reference to these plants being abundant and being browsed by forest antelopes.

Historical note

John Medley Wood noted that "This plant does not flower every year; it is commonly believed to flower once in seven years only; this year, 1888, it has produced flowers in great abundance".

Gallery

Image:Isoglossa_woodii_flowers.JPG, Image:Isoglossa_woodii_flowers_close.JPG, Image:Isoglossa_woodii_seedlings.JPG, Image:Isoglossa_woodii_close_Pigeon_Valley_09_05_2010.JPG,

References

Bibliography

* Pooley, E. (1998). ''A Field Guide to Wild Flowers; KwaZulu-Natal and the Eastern Region''. .

External links

* {{Taxonbar, from=Q6085722 Flora of South Africa woodii