Discussion Whole Plant

Section A: Morphological Characters



In the present part, the different macromorphological characters of the studied caesalpinioid taxa are presented in cumulative tables in order to facilitate deducing the most important diagnostic characters.



1. Whole Plant (Table 19)



i. Habit: The taxa under investigation may be tree in 16 taxa or shrubs the remainder studied nine taxa. In this respect Rendle (1925) stated that Caesalpinioideae are trees or shrubs, more rarely herbs.

ii. Length: The studied taxa varied between tall plants in 11 taxa, medium in nine taxa or small five taxa.

iii. Texture: Rough (Tamarindus indica), prickly (Haematoxylum campecianum), spiny (Gleditsia caspica & Parkinsonia aculeata), Pubescent (16 taxa) or glabrous (Caesalpinia ferrea, C. gilliesii, Saraca indica & Senna alata).



2. Leaf (Table 19)



i. Composition: Simple in Bauhinia alba, B. hookeri, B. variegata & Cercis chinensis, Bipinnate (paripinnate) in Caesalpinia ferrea, C. gilliesii, Delonix regia, Parkinsonia aculeata & Peltophorum africanum, oncepinnate (paripinnate) in 14 taxa or oncepinnate & bipinnate (paripinnate) in Gleditsia caspica & Haematoxylum campecianum.

The variations in leaf composition among the studied taxa are in accordance with the current taxonomic systems of classification, to cite but a few one can refer to Bentham & Hooker (1862), Post (1932), Emberger (1960), Engler (1964), Willis (1966), Brenan (1967), Hutchinson (1967), Pettigrew & Watson (1977), Smith (1977), Polhill & Raven (1983), Watson & Dalwitz (1983) and Lewis et al. (2005). Where Bauhinia and Cercis (simple leaf) separated in tribe Bauhinieae or Cercideae. Pettigrew & Watson (1977) segregated Haematoxylum away from the rest of related taxa viz. Ceasalpinia, Delonix, Parkinsonia and Peltophorum. The data in the present study support the segregation of Haematoxylum and Gleditsia (oncepinnate & bipinnate; paripinnate) away from the related taxa. Hutchinson (1973) pointed out that the variations in leaf composition of Caesalpiniaceae may indicate the general trend of evolution within the family vs simple-pinnate (imparipinnate)-compound.

ii. Shape of Blade: Suborbicular in Bauhinia alba, B. hookeri, B. variegata, elliptic-oblong Caesalpinia ferrea, oblong in six taxa, oblong-elliptic in Cassia grandis, C. javanica & Senna alata, ovate-lanceolate in Cassia fistula, Gleditsia caspica, Senna sophera, ovate-elliptic in Cassia nodosa & Senna surattensis, oblong-ovate in Senna didymobotrya, obovate in Brownea grandiceps, Ceratonia siliqua & Haematoxylum campecianum, cordate in Cercis chinensis, oblanceolate in Parkinsonia aculeata or oblong-lanceolate in Saraca indica. In the current study the shape of the blade distinguishes the Bauhinia sp. Under investigation away from Cercis chinencis. In the former the blade is suborbicular and cordate in the latter. This conclusion is comaparable with the work of Wunderlin et al. (1981, 1987) "tribe Cercideae or Bauhinieae is divided into two subtribes viz. Cercidinae (Cercis) and Bauhiniinae (Bauhinia)".

iii. Apex of Blade: Emarginated in Bauhinia alba, B. hookeri, B. variegata; caudate in Brownea grandis; acute in Caesalpinia ferrea, Cassia fistula, Senna sophera; obtuse in six taxa, cleft in Cassia grandis & C. javanica; mucronate in Cassia nodosa, Peltophorum africanum, Saraca indica; acute-mucronate in Gleditsia caspica; retuse in five taxa or acuminate in Cercis chinensis. The variations in blade apex support the segregation of the studied Bauhinia sp. away from Cercis chinensis. This is in accordance with the work of Wunderlin et al. (1981, 1987).

iv. Base of Blade: Cordate in Bauhinia alba, B. hookeri, B. variegata & Cercis chinensis; cuneate in. Caesalpinia ferrea, Gleditsia caspica, Haematoxylum campechianum, Parkinsonia aculeata & Saraca indica or obtuse in the remaining studied taxa (16 taxa).

The data extracted here are in accordance with some of the current taxonomic systems of classification viz. to cite but a few one can refer to Bentham & Hooker (1862), Post (1932), Emberger (1960), Engler (1964), Willis (1966), Brenan (1967), Hutchinson (1967), Pettigrew & Watson (1977), Smith (1977), Polhill & Raven (1983), Watson & Dalwitz (1983) and Lewis et al. (2005) where the studied Bauhinia sp. and Cercis chinensis are grouped under Bauhinieae or Cercidieae.







v. Margin of Blade: Serrate in Gleditsia caspica or entire in the remainder studied taxa.

vi. Stipules: Exstipulate in Cassia fistula, C. grandis & C. marginata; cresentiform in Cassia javanica, auricle in Cassia nodosa, cordate in Senna didymobotrya, spiniform in Haematoxylum campechianum & Parkinsonia aculeata; ovate in seven taxa, lanceolate in five taxa or linear in five taxa.



3. Inflorescence (Table 19)

i. Number of Flowers / Inflorescence: Few in five taxa viz. Bauhinia alba, B. hookeri, B. variegata, Cercis chinensis & Senna sophera and many in the rest of the studied taxa.

i. Length: Short in 11 taxa and long in the remaining taxa studied.

ii. Position: Leaf opposed in Bauhinia hookeri; axillary & terminal in Bauhinia alba, B. variegata & Cercis chinensis; axillary in 14 taxa or terminal in the remaining studied seven taxa.

iii. Type: Spike-like in Gleditsia caspica; corymbose in Saraca indica or raceme in the remaining studied taxa.



iv. Bracts: Ebracteate (Cassia fistula); deltoid (Bauhinia alba & B. variegata); suborbicular (Brownea grandiceps); subulate (Peltophorum africanum); scaly (Ceratonia siliqua, Cercis chinensis & Gleditsia caspica); ovate (ten taxa), ovate-lanceolate (Bauhinia hookeri, Cassia javanica & C. nodosa); ovate-oblong (Caesalpinia gilliesii, Schotia brachypetala & Tamarindus indica) or obovate (Senna alata).



4. Flower (Table 19)

i. Calyx Texture: Glabrous (ten taxa); tomentose (Cassia grandis & C. nodosa); velvety (Cassia javanica & C. marginata); pubescent in the remaining studied taxa.

ii. Colour: Red, pink, crimson or scarlet in ten taxa; brown in five taxa; green in eight taxa or yellow in S. alata & Tamarindus indica.

iii. Sepal Shape: Gamosepalous in Bauhinia alba, B. variegata & Cercis chinensis or polysepalous in the remaining studied taxa. The sepals may be lanceolate in Bauhinia hookeri, Delonix regia & Gleditsia caspica or ovat-lanceolate in Schotia brachypetala & Tamarindus indica; ovate in five taxa; obovate in four taxa; oblong Brownea grandiceps & Caesalpinia gilliesii; oblong-ovate in Cassia fistula; oblong-obovate in Senna alata or ovate-oblong in four taxa. The data in the oresnt study about the union of sepals support the conculsion reached before by Rendle (1925) "Bauhinieae have a gamosepalous calyx" except Bauhinia hookeri (polysepalous calyx).

iv. Number: For sepals in Brownea grandiceps, Gleditsia caspica, Saraca indica, Schotia brachypetala & Tamarindus indica or Five in the remaining taxa under investigation.

v. Corolla Texture: Apetalous in Ceratonia siliqua & Saraca indica; glabrous in 13 taxa; pubescent in the remaining taxa under investigation..

vi. Colour: Whitish green (Gleditisia caspica); white (Bauhinia alba & B. hookeri); yellow (11 taxa); red (Brownea grandiceps, Cassia marginata & Schotia brachypetala), lavender (Bauhinia variegata); pink (Cassia grandis, C. javanica & C. marginata) or scarlet (Delonix regia).

vii. Petal Shape: Obovate in nine taxa; obovate-elliptic in Cassia grandis, C. javanica; obovate-oblong in Haematoxylum campechianum, Schotia brachypetala & Tamarindus indica; ovate-elliptic in Cassia marginata & Parkinsonia aculeata; oblong in Brownea grandiceps & Gleditsia caspica; sub-orbicular in Bauhinia hookeri & Delonix regia; obconical in Bauhinia alba spathulate Caesalpinia gilliessii or ovate in Cassia nodosa.

viii. Number: In all the taxa under investigation the number of petals are five except Gleditsia caspica (four petals) and Ceratonia siliqua & Saraca indica (apetalous).

ix. Androecium Fertility: Ten fertile stamens in 12 taxa; three in Tamarindus indica, five in Ceratonia siliqua, seven in Saraca indica, eight in Gleditsia caspica, nine in Cassia marginata or 12 in Brownea grandiceps; seven fertile & three sterile stamens in Cassia fistula, C. nodosa, Senna alata & S. didymobotrya; six fertile and four sterile in S. sophera or five fertile & five sterile in Bauhinia alba & B. variegata.

x. Length: As long as petals in Haematoxylum campecianum, Schotia brachypetala, Senna sophera & Tamarindus indica; shortly exerted in Caesalpinia ferrea, Cassia fistula, C. nodosa, Ceratonia siliqua & Gleditsia caspica; longly exerted in Brownea grandiceps, Caesalpinia gilliesii, Cassia marginata & Saraca indica or included (not exerted) in all the remaining studied taxa.

xi. Filament Texture: Pubescent (Bauhinia hookeri, Haematoxylum campechianum & Tamarindus indica); hairy (Caesalpinia gilliesii, Cercis chinensis, Delonix regia, Parkinsonia aculeata, Peltophorum africanum); pilose (Gleditsia caspica); glandular (Caesalpinia ferrea) or glabrous in the rest of the studied taxa.

xii. Form: Awl-shaped in Peltophorum africanum or Filiform in the rest of the studied taxa. The latter may be sigmoid in Cassia grandis, C. javanica & C. marginata, nodulated in C. nodosa. The filament form (sigmoid & noduated) in taxa under investigation is comparable to those mentioned by Bentham (1871), Taubert (1891) and Randell (1976) who suggested that the filament form help in segregation of genus Cassia L. into three subgenera viz. Fistula, Senna and Lasiorhegma, or subgenera viz. Cassia, Senna and Absus respectively.

xiii. Anthers Size: Unequal in Cassia marginata, Senna alata & S. didymobotrya; subequal in Cassia fistula, C. grandis, C. javanica, C. nodosa, Senna sophera & S. surattensis or equal in the remaining studied taxa.

xiv. Attachement: Dorsifixed in Cassia grandis, C. javanica, C. marginata & Schotia brachypetala; basifixed in seven taxa or versatile in the rest of the studied taxa. In this respect Rendle (1925) distinguished tribe Cassieae by having more or less basifixed anthers.

xv. Ovary Texture: Glabrous in four out of the studied taxa viz. Caesalpinia ferrea, Cercis chinensis, Gleditsia caspica & Haematoxylum campechianum; the others with pilose in three taxa viz. Saraca indica, Schotia brachypetala & Tamarindus indica or pubescent in the rest (18 taxa).

xvi. Form: Flattened in nine taxa; oblong in 11 taxa or terete in the rest (five). Bentham (1871), Taubert (1891) and Randell (1976) concluded that the flattened and terete ovary enhance the separation of Cassia and Senna. This conclusion is in agreement with the data extracted in the present study particularly in that point.

xvii. Setting: Sessile in Caesalpinia gilliessii & Delonix regia; subsessile in seven taxa or stipitate in the remaining studied taxa.

xviii. Style Length: Short in eleven out of the studied taxa or long in the remainders.

xix. Form: Flattened in five out of the studied taxa viz. Bauhinia alba, B. hookeri, B. variegata, Haematoxylum campecianum & Senna surattensis; teret in ten taxa or filiform in the remainder.

xx. Curvature: Upcurved in Cercis chinensis; straight in seven taxa or incurved in the rest.

xxi. Stigma Form: Capitate (Bauhinia alba, B. hookeri, B. variegata, Brownea grandiceps); sub-capitate (Cercis chinensis & Tamarindus indica); concave (Caesalpinia ferrea & Haematoxylum campecianum); truncate (Caesalpinia gilliessii & Delonix regia); peltate (Ceratonia siliqua & Peltophrum africanum) or simple in the remainder.

xxii. Pod Texture: The pod not available in Brownea grandiceps; pubescent in Cassia grandis, Senna didymobotrya & S. surattensis and glabous in the remainder.

xxiii. Colour: Yellow in Haematoxylum campecianum or Brown in the rest.

xxiv. Form: Linear in six taxa; linear-oblong in Cercis chinensis; oblong in 12 taxa; terete in four viz. Cassia fistula, C. javanica, C. marginata & C. nodosa and elliptic in Haematoxylum campecianum.

xxv. Dehiscence: The pod dehiscent in 13 taxa or indehiscent in 11 taxa.

xxvi. Apex: Acut in Senna alata; mucronate in Haematoxylum campecianum; cuspidate in Bauhinia hookeri & Senna didymobotrya; tapering in Cercis chinencis, Parkinsonia aculeata & Peltophorum africanum or obtuse in the remaining studied taxa.

xxvii. Peak: Peakless in six out of the studied taxa; long in Bauhinia alba, Bauhinia variegata & Delonix regia or short in the remainders.

xxviii. Type: Membranous in Haematoxylum campecianum; crustaceous in Tamarindus indica; sub-woody in Caesalpinia ferrea, Gleditsia caspica & Saraca indica or woody in eight taxa or coriaceous in the remainder.

xxix. Seed Colour: Not available in case of Brownea grandiceps & Cassia nodosa; orange in Cassia fistula; black or greenish black in Cercis chinensis, Saraca indica & Senna alata; green in Senna didymobotrya and brown in the remaining taxa.

xxx. Form: Teret in Parkinsonia aculeate; sub-terete in Delonix regia, & Saraca indica; compressed in 12 taxa or flattened in the remaining taxa.

xxxi. Shape: Ovate in Caesalpinia ferrea, C. gilliesii, Cassia fistula, C. marginata & Schotia brachypetala; obovate in Ceratonia siliqua & Senna surattensis; orbicular Bauhinia alba, B. variegata, Cassia javanica & Tamarindus indica or suborbicular in Bauhinia hookeri; elliptic in Cassia grandis & Gleditsia caspica; pear–shaped in Senna alata & S. sophera or oblong in the remainder.