Module 2 - Extra-floral nectaries

[Mellifera Crofter]

I feel confused between laurels and cherries and plums, and the position of their extra-floral nectaries.

Point 2.23 of the guidance notes requires us to be able to describe the extra-floral nectaries of cherry laurel, cherry and plum - all three are Prunus species. Celia Davis says that in some cherries (Prunus spp) the extra-floral nectaries are on the petioles, but it seems that the extra-floral nectaries of Cherry laurel (also a Prunus - Prunus laurocerasus) are on the underside of the leaf (http://www.bee-craft.com/extra-floral-nectaries/) as in the case of Laurel (Laurus nobilis).

So, do some Prunus species have extra-floral nectaries on petioles and others have them on leaves? And what about plums then? I can't find any information about their extra-floral nectaries.

Kitta

[masterbk]

Before the plum and cherry trees lose their leaves (only a few weeks to go) suggest you go and have a look at their leaves. Both Plum and cherry have obvious extrafloral nectaries on the upper surface of the petiole and very close to the base of the leaf. Laurel do have them on the underside of the leaf near the base of the leaf on either side of the midrib. Bracken also has nectaries which indicates that nectaries predate flowers (probably to attract ants).

[Mellifera Crofter]

Thank you, Masterbk. I think my mistake was to have misunderstood Celia Davis. She said 'species of cherry (prunus spp)' have extrafloral nectaries on the petioles - so, not all prunus species as I've interpreted it. Cherry laurel (Prunus laurocerasus) and laurel (Laurus nobilis) have them on their leaves. I've just discovered that Stinkwood is also a prunus specie (Prunus africana), and their extrafloral nectaries are on the edges of the leaves, and I've planted some Myrobalan plums (or cherry plums - Prunus cerastifera) early this year, and I can't see that they have any extrafloral nectaries - so there seems to be a huge variety of positions of extrafloral nectaries on prunus species.

I'll try and find plum and cherry trees before the leaves fall.

Interesting point you mentioned about the bracken.
Kitta