Unit 23 (023)

1. Apomixis

Crataegus or hawthorns are apomictic like raspberries (Rubus).

Apomixis is an asexual type of reproduction through seed. The plant embryos grow

from egg cells without being fertilized by pollen (the male part of the plant).

For this reason, over 1100 species of Crataegus have been described, but there

probably are only a few hundred species. Since each apomictic plant colony can be

a little different in characteristics, it makes species definition a problem.

2. Hawthorns (Crataegus)

Crataegus have winter buds that are easy to recognize; they are short, fat, and reddish

in color, with imbricate or overlapping bud scales.

Hawthorns will grow in poor sites and are drought tolerant.

They have a horizontal or layered branching pattern, and often leaf out late in the

Spring.

3. Hawthorn Leaf Blight

Hawthorn leaf blight causes angular brown spots on the leaves, and then the leaves will

turn brown and fall off early in the season.