Longest legume inflorescence in Sri Lanka

The recent record of an unusually long inflorescence of Cassia fistula (‘Ehela’) from Sri Lanka, reaching up to 238 cm can be considered as the longest recorded legume inflorescence. In the world of legumes, records surpassing such lengths are very rare and are not well authenticated. Therefore, the present record can be considered as a strong contender for the longest inflorescence in the legume family.


INTRODUCTION
The legume family (Leguminosae or Fabaceae), commonly known as Pea or Bean family is the third largest flowering plant family in the world with over 17,000 species in about 730 genera (Heywood, 1993) However, in Sri Lanka, it is the largest family with 402 species (Rudd, 1980;1991a;1991b;Kostermans, 1980;Maxwell, 1991;Pedley and Rudd, 1996).Cassia is a well known genus in the tropics and consists of over 500 species.In Sri Lanka, the genus is represented by 30 species and is the second largest legume genus, next to Crotalaria (32 species).

Cassia fistula ('Ehela')
Cassia fistula, known as 'Ehela' in Sri Lanka is native to South and Southeast Asia.It is widely grown as an ornamental tree in many tropical countries of the world due to its profuse blooms, often with the tree crowns covered with flowers, at times when almost no leaves are borne by the crown.The tree grows naturally in dry climates, but it can be easily cultivated in the Wet zone.It grows best in full sun, on well-drained soils and is relatively drought-tolerant and slightly salttolerant.
The popularity and cultural importance of C. fistula is evident by its adoption as the national tree and the national flower of Thailand, the state tree and the state flower of Kerala State in India and the provincial flower of the North Central Province in Sri Lanka.It is known as the Golden Shower tree, Shower of Gold or Pudding Pipe tree in English, 'Konrai' in Tamil and 'Bendra lathi' in Hindi.
Cassia fistula is a relatively fast-growing, medium-sized tree, reaching up to 10 m and even up to about 20 m under optimal soil and moisture conditions.The leaves are deciduous, 15-60 cm long, pinnately compound with 3-8 pairs of leaflets, each leaflet 7-21 cm long and 4-9 cm broad.The flowers are produced on pendulous racemes 20-45 cm long (Perry, 1992;Rudd, 1991a; Fig. 1A).Each flower is 4-7 cm in diameter and with five yellow petals of equal size and shape (Fig. 1B).The fruit (pod) is cylindrical, 30-60 cm long and 1.5-2.5 cm in diameter, with a pungent odour and containing a series of disc-shaped seeds that are poisonous.The tree has strong and durable wood that has been used to construct the famous 'Ehela kanuwa (pole)', on the climb to Adam's Peak.In Ayurvedic medicine, it is known as 'Aragvadha', meaning 'disease killer'.Its roots are considered a very strong purgative, however, self-medication without medical supervision is strongly advised against in Ayurvedic texts.

Length of inflorescence in legumes
The long inflorescence in legume species are invariably racemose.
In racemes the inflorescence axis (peduncle) grows indefinitely producing a series of flowers from its base up to the apex (centripetal development).The basal flowers mature first and either fall or develop pods, while flower buds towards the apex continue to open in sequence.Racemes, due to their long and slender nature, are invariably pendant.The lengths of the inflorescence in legume species, both native and exotic, occurring in Sri Lanka, as recorded in the literature, are shown in Table 1.__________________________________________ Author's email: magdonj@emlconsultants.com