Question

Written description of the plant family vitaceae. Please include overall morphological description with synapomorphies highlighted and floral morphology.

Answer 1

Vitaceae comprise a family of dicotyledonous flowering plants. This family is represented by 14 genera and 910 species. It is distributed in damp tropical countries. Xerophytic forms are found in Africa and south America.

Identifying characters:

• Plants are generally climbing shrubs, tendrils or small trees.
• Root is branched.
• Stem is weak, borne at the nodes which lie opposite to the leaves. Stem is a sympodium. Often stem can be erect, nodes swollen, tendrils develop adhesive discs.
• Leaves compound or simple; alternate or opposite, rarely deeply lobed, the margins of the leaf are expanded into membranous stipules.
• Inflorescence is spike, racemes, panickles.
• Flower- small, actinomorphic, regular, hermaphrodite, usually monoeciuos; often dioecious in some species, hypogynous/ perigynous.
• Calyx- Sepals 4-5, connate/ cupshaped, shortly toothed.
• Corolla- Petals 4-5 caducous, connate at apex, valvate
• Androecium- Stamens are 4 to 5 in number, inserted in a direction opposite to that of petals, annulus expanded/ glandular.
• Gynoecium- Carpels many, 2 to 8 in number, syncarpous, ovary superior in nature. Ovary 2-6 celled, each locule with anatropous ovule, style simple, stigma capitate or discoid.
• Fruit is a berry; juicy in nature, succulent.
• Seed- hard testa, embryo smallin nature. Endosperm is ruminant.

The family is closely related with Rhamnaceae. The similarities shared includes the number of petals in the flower structure. Also, the anthers being antipetalous, pistil bicarpellary. It shows differences in climbing habit with Rhamnaceae. The climbing habit is rare. Moreover, the flowers are never epigynous in case of vitaceae.

Studies show that vitaceae is also an ancestor of Rutaceae.It can be attributed to the fact that the antispalous whorl of stamens remains suppressed; the presence of peduncle dots in leaves also contributes to this.

Synapomorphy:

Putative synapomorphies of Vitaceae include raphide sacs, glandular hairs,valvate corolla, specialized stalks, stamens opposite to petals, berries with seeds. The seeds have a cordlike raphe on their adaxial surface,extending from the hilum to the seed apex.