Saturday 7 February 2015

Family Agavaceae

Agavaceae Dumort. description.

General/Distribution
 A tropical and subtropical family with 20 genera and c. 670 species mostly in the New World. Agave species are cultivated for their fibres, used in making ropes, mats etc. Some other species are cultivated for ornamental purposes. Represented in Pakistan by 6 naturalized or cultivated genera, 4 of which Cordyline, Furcraea, Polianthes and Sansevieria are grown as garden or potted plants.
DescriptionPlants perennial, polygamous or dioecious, rhizomatous often arborescent. Stem short. Leaves usually crowded at the base of the stem, often succulent, entire, or with a prickly or toothed margin. Flowers bisexual or unisexual. Inflorescence racemose or paniculate, often on a thick scape. Perianth segments 6, free or united. Stamens 6, free, ± adnate to the perianth lobes. Anthers 2-locular, dorsifixed. Ovary superior or inferior, 3-locular. Placentation axile. Ovules 1-many in each loculus, sytperposed. Fruit a loculicidal capsule or berry. Seeds compressed.
Included in the Amaryllidaceae by some authors and Liliaceae by others, but best recognised as a separate family based mainly on the arborescent habit, absence of bulbous parts and a large paniculate or racemose inflorescence.

Key For Identification
1. Ovary superior
2. Perianth segments free

2. Perianth segments united at the base
3. Ovules numerous

3. Ovules solitary

1. Ovary inferior
4. Flowers zygomorphic; inflorescence spicate or racemose

4. Flowers actinomorphic; inflorescence usually 
5. Stamens larger than the perianth, filaments thread-like

5. Stamens shorter than the perianth, filaments thickened in the lower part

Floral Formula of Agavacea


Agavaceae Floral Formula


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