Is the pictured seedling a Sycamore or field maple?

Question

I recently dug up a 3 year old self seeded specimen from my garden that I intend to bonsai after I move house. I originally thought it was a field maple (Acer campestre) but am starting to suspect it may in fact be a sycamore (Acer pseudoplatanus).

Any help / confirmation of the species / variety would be very much appreciated, as I know sycamore can be harder to achieve leaf reduction.

Answer 1

The leaf margins are serrated, which makes it a Sycamore. From the Wikipedia article for Acer pseudoplatanus:

The leaves are opposite, large, 10 to 25 cm (4 to 10 in) long and broad, palmately 5-lobed, with pointed, coarsely serrated lobes.

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And for A. campestre:

The leaves are in opposite pairs, 5–16 centimetres (2.0–6.3 in) long (including the 3–9 centimetres (1.2–3.5 in) petiole) and 5–10 centimetres (2.0–3.9 in) broad, with five blunt, rounded lobes with a smooth margin.

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