many other ancient important crops are also thought to lack living relatives from
which they originateddirectly(which is not to say that they lack living relatives).
Examples of familiar crops for which direct living ancestors are believed (some-
times debatably) to be extinct include avocado (Persea americana), cassava
(Manihot esculenta), corn (maize; Zea mays), eggplant (Solanum melongena),
European plum (Prunus domestica), lemongrass (Cymbopogon citratus), onion
(Allium cepa), peanut (Arachis hypogaea), rice (Oryza sativa,O. glaberrima) and
safflower (Carthamus tinctorius).
1.11 Alternative Classification Systems forCannabis
1.11.1 Classification of Cannabis Assemblages
as Conventional Taxa
Beginning with a code governing botanical nomenclature prepared in 1867,
improved internationally accepted versions have been published periodically. The
latest isThe International Code of Nomenclature for Algae, Fungi, and Plants
(ICNAFP; McNeill et al. 2012 ). This is the most respected and universally applied
way of determining plant names. The code specifies the conventions that must be
followed for naming taxonomic groups, but different taxonomists can disagree
about which individuals fall within given groups (i.e. the circumscription of groups)
and about the hierarchical organization (i.e. ranks assigned to groups). When a
name has been used in different senses so extensively that it is a source of con-
fusion, Article 57 of the ICNAFP provides for stabilizing usage of, or simply
abandoning that name. Certainly there has been extensive confusion over how to
use some of the species names associated withCannabis, but no one has yet
suggested that Article 57 be applied.
There is no impediment to treating groups that are completely or partly
domesticated, such asCannabis, under this code. Nevertheless, many plant tax-
onomists have been troubled by the appropriateness of conventional categories of
the code (species, subspecies, variety) for groups in which there are both wild and
domesticated kinds. There have been many proposals. For example, Harlan and de
wet ( 1971 ) suggested that where both ruderal and domesticated races exist within
one species, all of the ruderal races should be recognized as a collective subspecies,
and in parallel all of the domesticated forms should be placed in a collective
cultivated subspecies. Similarly Nesom ( 2011 ) treated apparent wild progenitors
and their domesticated derivatives in the family Cucurbitaceae as separate sub-
species of a given species. However, there is no agreed way of taxonomically
separating domesticated plants and their close wild relatives, and indeed very
limited prospects for the adoption of a universal solution to this issue.
46 E. Small