These 3 all grow in fairly close proximity at Camley Street Natural Park, as well as appearing in the same section in Rose (The Wild Flower Key), so this week my botany buddy, Sylvia, and I had a go at using them to learn some differentiating features of the Rosaceae and revise the names of some structures.
I'm pretty confused by the Rosaceae! There seem to be many exceptions when trying to pinpoint differentiating features: they mostly have 5 petals (some have 4!), they often have lobed or divided leaves (but not always!), carpels are usually numerous (but some only have one!)...
What I have figured out, though, is that they all have:
I'm pretty confused by the Rosaceae! There seem to be many exceptions when trying to pinpoint differentiating features: they mostly have 5 petals (some have 4!), they often have lobed or divided leaves (but not always!), carpels are usually numerous (but some only have one!)...
What I have figured out, though, is that they all have:
- stipules
- alternate leaves
- separate petals
- an enlarged, cup-shaped receptacle (Hypanthium) which surrounds the ovary
- numerous stamens
Agrimony, Agrimonia eupatoria
Wood avens, Geum urbanum
I had always thought of this as a scrappy little plant - a weed on my allotment and not very attractive. But get in there with a hand lens and this is what you'll see:
The fruiting head of wood avens is pretty spectacular with long red zig-zagging styles, which when dry, form hooked spines. Each ovary becomes an achene (nutlet) with a single seed inside.