Author: Linnaeus
Morphological description
Trees or large shrubs .
Leaves spirally arranged, often distichous, paripinnate; extrafloral nectaries not present.
Inflorescence racemose (Cassia javanica ov 428822 ), terminal on main shoots or on short side shoots; pedicels with 2 bracteoles at or shortly above the base.
Flower . Hypanthium variable. Calyx 5-merous, sepals reflexed at anthesis. Corolla zygomorphic, 5-merous. Androecium zygomorphic, 10-merous, filaments of 3 abaxial, antesepalous, stamens sigmoidally curved (Cassia fistula fl 255219 ), usually longer than their anthers, dehiscent by slits; the remaining 7 filaments straight and short with anthers mostly dehiscing by basal pores.
Pods elongate, cylindric or compressed, indehiscent.
Seeds many, 1- or 2-seriate; funicle filiform.
Distribution
About 30 species, in tropical America, Africa, Asia, Malesia and Australia. In Malesia there are three introduced species and only one indigenous.
Habitat
In forests at low altitudes.
Notes
1. In the present treatment Larsen & Hou (1996: 556) have followed the generic concept of Irwin & Barneby (1981: 97--106), who through three decades have studied the Tribe Cassieae of the New World and proposed a reorganisation of the tribe. This has now been generally accepted even if it breaks with the most common arrangements in floras and herbaria. In the `neighbouring' floras, i.e. Flora of Thailand and Flore du Cambodge, du Laos et du Viêt-Nam, the genus Cassia has been treated in its wider sense. Larsen & Hou (1996) have, inconveniently, decided to follow the newer system, partly because it is widely accepted, e. g. by the ILDIS-database, partly because Irwin and Barneby have reevaluated and typified a number of widespread taxa in our region, and finally because the great majority of the species occurring in the Malesian region are introduced, cultivated or, in several cases, naturalized. In the genus Cassia only one species is indigenous, in Genus Senna probably only 3 out of 17 treated here, and in Genus Chamaecrista one or two only.
2. The Genus Cassia differs from the Genus Senna in having bracteoles, whereas they are absent in the Genus Cassia, and in having 3 fertile stamens with sigmoid curved filaments (Cassia fistula fl 255219 ), in stead of straight ones.
EXCLUDED SPECIES
A number of species of Cassia and of the Genus Senna (see there) were occasionally recorded as in cultivation in Malesia . They have not been included in the present treatment.
Cassia roxburghii DeCandolle (syn. C. marginata Roxb.) is native to S India and Sri Lanka. It has been introduced to W Malaysia as an ornamental (`red Cassia ') but is not found naturalized or escaped. It is related to Cassia javanica , but has smaller leaves, glabrous anthers, the style dilated and abruptly hooked at apex, and the stigma retrorse (roxburghii Cassia fl 256057 ).