Taxonomy of Vascular Plants Practical (18.2.2011)

Zingiberales order is what I learn on  that day. During the practical session, we had to distinguish the inflorescence of each family  by drawing and labeling the specimen and also determine the floral formula. 

The Zingiberales order is made up of 8 families, mostly tropical plants that are commonly grown as ornamental. They also have culinary and medicinal uses. Specific characteristics which distinguish the Zingiberales from the other plants include;

• Rhizomatous herb

• Young leaf roll and present or midrib

• Present of ligule

• Involucral bract

• Stamen and filament formed staminoid structure

• Zigomorphic flower

Out of 8, we only given 3 species of different family; Cannaceae, Heliconiaceae and Musaceae. 

Cannaceae (Canna indica)

Cannas are distinguished by the presence of mucilage cells and a petal like style fused to a single fertile stamen.  The flower is a bisexual which mean male and female part are in the same flower, often lasting only a day. Have 3 distinct, imbricate sepals and 3 connate, imbricate petals. Have 1 functional stamen. The filament connate with staminodes; adnate to corolla while the anther is unilocular. 3 or 4 petaloid staminodes; 1 larger than the others and recurved, all basally connate and adnate to corolla. 3 carpel are connate and the ovary is inferior with axile placentation. Ovules numerous in each locule. There are nectaries in septa of ovary. The fruit is warty capsule and usually splitting irregularly by disintegration of the fruit wall.

Heliconiaceae (Heliconia psittacorum)

 

Heliconias are attractive tropical plants with banana-like leaves and beautiful. Long lasting inflorescences composed of showy bracts which contain the true flowers. It may be distinguished from other members of the Zingiberales by their inverted flowers, a sterile staminode and fruits which are drupes. The flowers are bisexual. Its inflorescence do have branch, persistent, colored bracts in the axils of which are fascicles of flowers with petaloid tepals and large herbs with 2-ranked leaves. The fruit has a single hard seed per locule.

Musaceae (Musa acuminata)

Musaceae is a family of banana.  The flowers are zygomorphic and functionally uni sexual or bisexual, the proximal ones being female and the distal ones male. There are 2 tepals; compound tepal and 1 free tepal. The androecium usually consists of 5 fertile stamens and a staminode that is opposite the free tepal. The gynoecium consists of a single compound pistil of 3 carpels, a single style and an inferior ovary with 3 locules, each containing numerous axile ovules. 

Can you see the differences between the male and female?? I didn't zoom in my lens for female. Equally in the same length when I take a photo of them. Female part especially the ovary is bigger than the male. This is because this part eventually become a banana fruit. Here is a picture of female ovary that have been cut it into 2;

My report: