If I was writing about an apple tree, I wouldn't write Apple tree, likewise with fir trees. If I'm writing about laburnum or acacia trees are they also not capitalised - also generic? I think they're not, but am having doubts and it's proving impossible to find the answer by researching. Anybody sure of the answer?
Also 'of course, my darling.'- should this be my Darling with a capital D?
Becca.

laburnum or acacia

Strictly speaking there are genus names and so should start with a capital letter. If it is a non-fiction piece they should also be in italics.
However, when suffixed with 'tree' they are conferred comnon name status and can be placed in lower case.

- Naomi

<Added>

Doh! they not there

There was recently a thread on this:

http://www.writewords.org.uk/forum/65_143045.asp

Hope it helps

Casey

Hi Naomi,
Thanks, yes, that feels right.
Casey, thanks for directing me to the other thread. I did write something there re Darling standing in for someone's name. I'll use that system anyway for now. These things are annoying aren't they? I've just got things straight with possessive apostrophes in people's names, and that makes me feel better!
Becca.