mature seeds or fruits remain on the plant. This reduction of“shattering”(natural
shedding of seeds at maturity) is the most important way that humans have
domesticated the majority of seed crops (Harlan 1995 ; Fuller and Allaby 2009 ). In
cereals, a“domesticated syndrome”of characteristics is recognizable whereby the
“grains”(fruits technically termed caryopses in the grass family) have lost the
features in their wild ancestors that cause them to detach and scatter away (see, for
example, Sakuma et al. 2011 ). A parallel syndrome of characteristics promotes seed
retention in domesticated C. sativa. The fruits of wild plants possess a
well-developed abscission zone and a basal“neck”(attenuated area), both facili-
tating disarticulation as soon as the fruits are ripe, and this is essential given the
considerable predation by birds on seeds that remain attached to the plant.
A camouflagic mottled layer covers the achenes of wildC. sativa, providing
some protection for the fallen seeds against mammalian, insect and avian
Fig. 1.3 Achenes (“seeds”)ofCannabis sativa(areas of attachment to the plant are indicated by
arrows).Left columnshows achenes of domesticated plants,right columnshows achenes of
ruderal plants.Top row(a,b) shows light photomicrographs,bottom row(c,d) shows scanning
electron photomicrographs. The domesticated fruits are larger, lack a camouflagic persistent
covering layer derived from the perianth, and lack an elongated attachment base that facilitates
disarticulation in the wild form
10 E. Small