Evolution of Seed Habit Part 8

Evolution of Seed Habit Part 8

Caesalpinia Ceae: Cassia Family

This family includes about 152 genera and about 2300 species. In Pakistan the family is represented by 16 genera and about 60 species.

Familiar plants: Tamarindus India; cassia fistula. Bauhina veriegata.

Fig. 9.28 Caesalpiniaceae: Cassia senna; A twig, B-flower; C-fruit

Vegetative Characters Habit: mostly trees or shrubs, some are woody climbers; rarely herbs. Stem: Erect, woody herbaceous, or climbing. Leaves: compound, pinnate, very rarely simple, stipulate.

Floral characters: Inflorescence: Axillary or terminal raceme or panicle or spikes, rarely cymose; showy. Flowers: bisexual, zygomorphic, rarely actinomorphic, perigynous. Calyx: sepals 5, free or connate at base, often colored. Corolla: mostly 5 petals, free. Androecium: stamens 10 or fewer, rarely numerous, free or variously united. Gynoecium: a simple pistil 1-carpel; ovary superior, unilocular; placentation marginal; stigma simple. Fruit: legume.

Economic importance: the family is of great importance. Some plants are ornamental, some have medicinal importance, a few have food and other values.

The leaves of Cassia alata are used to cure ring worm and skin diseases. Cassia senna and C. obovata are cultivated for the leaves which yield the drug Senna, which is the base for a laxative. Oil extracted from the seeds of Cynometera cauliflora is applied externally for skin diseases.

Common ornamental plants are bauhinia variegate (kachnar),cassia fistula (amaltas), parkinsonia, etc.

The leaves and flower’s bud of bauhinia variegate are used as vegetable. The acidic fruit of tamarindus indica are edible and are rich in tartric acid. The bark of Bauhinia and Tamarindus Indica is used in tanning. The heartwood of Haematoxylon (longwood) yield the dye haematoxylin.

Mimosaceae: Mimosa or Acacia Family:

A family of about 56 genera and about 2800 species. In Pakistan it is represented by 11 genera and 49 species, of these only 4 genera and 18 species are native and rest are introduced.

Familiar plants: acacia nilotica, albizzia lebbek, mimosa pudica Touch me not,prosopis glandulosa, P.cineraria.

Vegetative characters: habit: mostly trees or shrubs, rarely climbers or herbs. Most of themare xerophytes. Stem: mostly woody. Leaves: pinnate by compound, alternate, stipulate, stipules modified into thorns.

Floral characters: Inflorescence: spike like or head or umbel, rarely racemose or globose umbels. Flowers: Bisexual, actinomorphic, hypogynous to slightly perigynous, bracteates. Calyx: usually sepals 5, generally fused, toothed or lobed. Corolla: petals 5, free or fused; corolla lobed. Androecium: stamens 5 to numerous, free, or adnate to the base of corolla. Gynoecium: a simple pistil of 1 carper, ovary unilocular, superior; ovules many, placentation marginal. Fruit: a legume dehiscent or indehiscent.

Economic importance: many trees of this family including species of Acacia, Albizzia and Xylia provide commercially important wood, which is used for construction purpose or for furniture or as a fuel. The wood of Albizzia lebbek is used in cabinet work, and railway carriages.

Arabic gum is obtained from Acacia nilotica and A. Senegal. Katha a dye is obtained from Acacia catechu. The tender leaves of Accacia nilotica are used as blood purifier.

Some common garden plants grwn for their beautiful flowers are mimosa pudica and Acacia melanoxylon. A few species of prosopis are planted in the arid zones for breaking the wind pressure.

Fig 9.29 Mimosaceae: Prosopsis cineraria; A-twig, B-infloresence; C-flower; -D-fruits.