Harlan and de Wet 
genetically classified sorghum into primary gene pool, secondary gene
pool, and tertiary gene pool; this was also partly encountered in folk
taxonomy. For instance, some farmers are trying to classify pearl
millet into sorghum, which is a secondary gene pool for sorghum.
Farmers classified sorghum into cultivated and wild species
(spontaneous races); this is compatible with primary gene pool of
sorghum . Genetically, edible sorghum and non-edible ones belong to the same biological species.
The classification of wild and cultivated sorghum has been
accommodated by dynamic property, non-exclusive and flexibility in
classification of folk taxonomy. As pointed out by Berlin et al., ,
these are common characteristics of folk biology. In the course of
classification and naming, the following scenarios particular to folk
taxonomy have been encountered which implied for the use of integrated
the same name can refer to different varieties. Afukanni and Kuffa Kassa in
the intermediate and lowland areas refer to different varieties, though
the different varieties have the same name. For example, Afukanni refers to an early maturing variety i.e. varieties with other different characteristics but which matures early is called Afukanni.
It is more of a general name referring to early maturing varieties.
Polysemics was also encountered in improved varieties. A drought
resistant variety either improved or farmers can be named as Kuffakassa because of drought resistance per se. This is a lumped name. However, improved variety T76 #23 is called Afukanni in Babile and in Dire Dawa, indicating the consistency in polysemics in different localities.
Shefere, Jefere, Chefere; She', Je' and Che' are the semantics used in different localities, they might represent the same folk species. Fechee and Fechatee might refer to the same folk species but the way it is called varied in the different locality.
Multiple names for one folk species/variety
One variety can have more than one name: Zengada (by Amhara farmers), Fitibile and Chiquere (by Oromo farmers); Arebe (coming from Arab countries), Yemeni (possible origin of the variety might be from Yemen) and Umrahjeria refer to the same variety but named after its whitish rocky seed colour.
New names are given to some varieties within one folk species
For instance, one of the varieties of Muyra folk species is named as Hamdye, as it is an earlier maturing and drought resistant type. Keyla is one type of Fendisha folk variety that has light red seed colour and insipid stalk types.
Naming of Improved Varieties
Few varieties which are adopted by the farmers in the lowland areas
are given various names depending on the conditions. For example, an
improved variety-Gambella 1107, in Dire Dawa, is named as Kuffa Kassa (because of its drought resistance), Afukanni (because of its early maturity), Manahile (introduced by farmer Manahile), Esapako (its time of introduction coincides with Socialist Party System). Afukanni is given to Gambella 1107, T76#23 and IS 9302 because all of them do mature earlier than farmers varieties.
The folk names are sometimes limited by the relative importance of folk species and varieties to particular village (ganda), farming community, ethnic groups or weredas. As indicated in Table 9,
the importance of folk species varied and most of them have increased
local importance with the exception to some folk species that were
widely and popularly known across the region.
The meaning of the names of some of identified folk species is not
known. It is difficult to know unless the people who named it or the
place of origin is traced back. The original name is adopted and
maintained with variety in the course of farmer-to-farmer
dissemination. A similar pattern was observed in rice .
Folk taxonomic nomenclature is an integral part of the variety management in many farming systems [21-23].
In view of this, the multitude of names at various folk taxonomic
levels indicated the prevalence of on farm genetic diversity at
infra-specific level. This is also in agreement where folk taxonomy is
used to highlight the amount of genetic diversity [24,25]. In this study, over 78 folk species (Table 9)
have been identified which indicated the level of on farm genetic
diversity. The variation among naming connotes geographical, genetical
and ecological diversity. Diversity is reflected in the multiplicity of
names farmers have been using for different folk species. This is also
in agreement with ethno-biologists [26-29] who pointed out that rich folk knowledge is one of the factors accounting for maize diversity in Mexico.
It has been repeatedly shown that inter-specific folk taxonomy are accurate [26,30]
but a doubt shadows over accuracy of intra-specific level. Formal
taxonomy has failed most conspicuously at the intra-specific level in
cultivated plants .
This has to be evident in that the formal taxonomy is using strict
taxonomical parameters while the folk taxonomy, in addition, has
functional, adaptive and use related parameters, which might result
either in splitting or lumping of the class of formal taxonomy. This
partly disagreed with the findings of Teshome et al.  in which there was full consistency.
Inconsistencies are not only within folk taxonomy but also in formal taxonomy .
Confusion in folk taxonomy extends over the generic, specific and
infra-specific level. For instance in formal taxonomy of sorghum,
Snowden  used 31 species of cultivated groups; Jackushevsky  reduced these to nine and de Wet and Huckabay  to one. The similarities in the folk species lead to confusion among the farmers and this was also encountered by Boster  which finally resulted in 'splitters' and 'lumpers' (Figure 5, Table 10). Similarly, Harlan 
indicated that conventional formal taxonomy tends to over classify and
provide too many categories. Hence, an informal system based on gene
pools, races and sub-races is proposed.
Most of the folk taxonomy descriptors are in agreement with formal taxonomy ones developed by IBPGR/ICRISAT .
In addition new folk taxonomy descriptors related with glumes, panicles
and nodal tillers have been identified to be used in the formal
The outer glume colours of sorghum as per ICRISAT/IBPGR descriptors
are scored as a single colour. However, it was found that in the study
area most of the glume colours compose more than one colour. Hence, the
formal glume colour descriptors have to add categories of multi-colored
glumes, e.g., Jeldi is partly straw-red glume coloured.
Though theoretically there is one glume colour per head, the number of
folk species with more than one colour per panicle was not few in this
study. It can be uni-or multi-colored, e.g., Fechatee-straw
and black coloured glumes per panicle. In the ICRISAT/IBPGR
descriptors, it has never taken into account the inside glume colour.
However, farmers clearly showed that varieties with similar outer glume
colour but different inside glume colour, e.g, Arebe folk species.
ICRISAT/IBPGR descriptor for panicle types provide 12 type of
panicles, which was comparable to the folk panicle descriptors.
However, if we take the compact panicle type: it has only two versions,
elliptic and oval in the formal one. On the contrary, farmers indicated
at least four types of tips that are stable inherited by folk species
and used as one of the distinct character for classifications. As
indicated in Table 2,
tip of the panicle can be flat, with tits, pointed or pigmouthed type.
Hence, more categories of panicle types have to be included. Besides,
the less accommodating formal descriptor categories for panicle types
have been felt in the morphological characterisation of folk species
such as Muyra, Wegere, and Fendisha.
In the ICRISAT/IBPGR descriptor, the normal evaluation of nodal
tillers is for either absence or presence. Flowering synchrony is
evaluated for basal tillers only. However, farmers indicated that
flowering synchrony of nodal tillers is one criterion for folk
taxonomy. Some of the folk species, for example Bedukanni folk species, have nodal tillers that synchronise in both flowering and maturity with the main tiller.
One of the salient importance's of folk taxonomy is that it makes
genetic resources collection and conservation simple, practical and
very objective. Actually, before any genetic collection, conservation,
characterisation and evaluation, prior information and study on folk
taxonomy is indispensable for systematic comprehensive germplasm
collection. A lot of sorghum germplasm, closer to 8000, have been
collected from Ethiopia . This collection was made without having apriori information
on folk taxonomy, which has resulted in the incomplete coverage of the
collection by folk species. One of the reasons for the duplication or
lack of exhaustive ex situ collection was due to lack of information on folk taxonomy in the course of collection and characterisation . This completely agrees with the idea of Boster 
that folk taxonomy of great intra-specific variability can be
understood as a means to maintain diversity and that diversity is
sought for its own sake and not for specific reason. These types of
appropriate folk taxonomic studies have to be made in the centre of
diversity and origin for enhancing genetic resources before the folk
taxonomic knowledge is eroded.
Folk taxonomy can help in identifying relative value of folk species/varieties (Table 7 and 8)
for proper characterisation and pre-breeding activities. A similar
study on rice in Nepal has shown that name of the varieties indirectly
related showed the functional value of the variety .
One of the major problems in breeding crops in centre of origin and
diversity is the problem of improved varieties to perform better than
farmer varieties mixture grown, as the farmers have many varieties in
their hands [14-17].
Hence, for cultivars development in these areas, folk taxonomic
classifications identify the important traits and varieties enhancement
program, crossing and evaluation. Besides, complementary varietal
components for varietal mixture can be bred.
Knowing folk taxonomy helps to identify the importance and distribution of the folk species and hence helps to develop an in situ conservation scheme for farmers' varieties. As indicated in Table 9, the relative importance of folk species varied hence it can help to assess and prioritise folk species and varieties for in situ and ex situ conservation .
Sorghum was commonly exchanged and distributed according to the folk names [16,17].
Exchange of sorghum between families was commonly referred to in terms
of specifically locally named varieties. Farmers in one village
generally know which households certainly have named varieties and
their particular agronomic and use value-related characteristics. When
asked about a particular variety, farmers often reported that they did
not have it but that it could be found in a particular household and
where it was cultivated. Knowing folk taxonomy also helps in developing
seed distribution, flow networks and regional varietal map.