Food Reservoirs

Several plants gather food like starch and sugars into their fruits and seeds and also into the modified form of stems and roots. Various fruits function as food reservoirs. For example, Malus sps., Prunus sps., Mangifera indica, Cucurbita sps., and grains of Triticum aestivum and Zea mays. Seeds of Pisum sativum function as food reservoirs. Roots gather food just like that is seen in the taproot of Daucus carota, Pastinaca sativa, Beta vulgaris, tuberous roots of Ipomea batatas, and Manihot esculenta. The root tubers do not have “eyes” or “buds” and they produce adventitious stems.

Stems also store food material. The different types of stem reservoirs are stem tubers, corms, cormels, bulbs, bulbets, bulbils, rhizomes, and so on. Stem tubers grow in the underground and have buds or eyes, which gives rise to new stems like in Solanum tuberosum, Caladium X hortulanum, and so on. Corms constitute stem tissue which is in the form of a condensed state with a topmost bud that gives rise to another stem. Gladiolus sp., is an example for corm. Small corms that exist around the large corm are called cormels. Bulbs are a form of stem reservoirs that possess a growing region or flower buds that are covered by fleshy and thick scales. Bulbs like Allium cepa and Hippeastrum sps., are called tunicate bulbs as they are secured from drying and mechanical damage with the help of dry and membranous outer scales called a tunic. There are some non-tunicate bulbs like Lilium longiflorum and its outer scales are separate and succulent. Bulblets are small sized bulbs growing from the main bulb such as Hippeastrum sps. Bulbils grow in the leaf axil regions on the stem. Bulbils may be small bulbs as seen in lilies and leafy appendages as seen in Alpinia purpurata, Dietes vegeta and Hemerocallis sp. Bulbils can be used for vegetative propagation. Rhizomes are stem reservoirs of food and help in vegetative propagation through division and separate parts. Examples of rhizomes are Polypodium polypodioides, Heloconia sps., Arundinaria gigantea.