A survey of some cucurbitaceae species in Kenya with an analysis of cucurbitacin content, and an identification guide to poisonous and safe species
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Date
1992
Authors
Njoroge, Grace Njeri
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
The Cucurbitaceae is a family of dicotyledonous plants.
For a long time the plants in this family have been
cultivated as sources of vegetables and fruits. Many of
the wild species are reported to be used locally as
sources of vegetables. While others are given to
domestic animals as fodder. Some of the wild species
however. have been reported to poison people as well as
domestic animals that may feed on them. Cases of
poisoning could be as a result of misidentification of
these species .
For investigation into this problem a total of 23
cucurbitaceous species were collected from Nairobi area
as well as from the surrounding areas. These plants were
identified and voucher specimens deposited at EA.
Cases of poisoning in cucurbitaceous species
have been attributed to the occurrence of a group of
triterpenoid compounds called cucurbitacins. The
presence or absence of these compounds in the various
organs of these cucurbitaceous species is determined
firstly by
test and
triphenyltetrazolium chloride
secondly by the infrared
precipitate
absorption
spectrophotometer. Individual cucurbitacins were
provisionally identified by thin-layer chromatography
with authentic samples. Presence or absence of the
toxic cucurbitacina was assessed in the various organs
which are used locally as sources of vegetables or
herbal medicines. It is possible from this work to
distinguish the plant parts with toxic cucurbitacina and
identify the plants in the field using the key
presented.
To make the results of this study available to the
local people who use them an identification key was
constructed . This key avoided technical botanical terms
.
which implies that it can be used by people without
botanical training to identify the plants in the field.
Simple illustrations are included in the key to aid
identification.
In addition, the local uses, distribution and flowering
times of these species were investigated. It is hoped
that the results of this work will reduce incidence of
poisoning
Description
Thesis submitted in partial fulfillment for the degree of Master of Science (Botany Department) in Kenyatta University, March 1992, QK 495.C96 N53