what is considered bulbous

Aqua Flora aquaflorasa@telkomsa.net
Sat, 26 May 2007 10:25:06 PDT

David Ehrlich wrote: Defining a geophyte is much more difficult. At best we can offer a fuzzy definition: The plant must be a perennial with a dormant period during which most if not all its living substance is kept in an underground storage organ.

A few definitions from the Oxford Dictionary of Plant Sciences:

Rhizome: A horizontally creeping underground stem which bears roots and leaves and usually persists from season to season.

Tuber: A swollen stem or root that functions as an underground storage organ.

Bulb: An underground storage organ, comprising a short, flattened stem with roots on its lower surface, and above it fleshy leaves or leaf bases, surrounded by protective scale leaves. It may provide the means for vegetative reproduction, or for the survival of the plant from one season to the next.

Geophyte: A land plant that survives an unfavourable period by means of underground food-storage organs (e.g. rhizomes, tubers and bulbs). Buds arise from these to produce new aerial shoots when favourable growth conditions return.

What about evergreen bulbs such as Crinum asiaticum which does not undergo a dormant period, can they be considered geophytes? What about Aloe modesta which has a swollen underground "bulb" comprising of leaf bases? Is this a succulent geophyte???

The Oxford definition of bulbous is: round or bulbous in shape. Perhaps we should content ourselves with accepting that if it looks bulbous it is bulbous.


South Africa

More information about the pbs mailing list