Till yesterday I thought I could tell an umbel from a corymb, but Douglas fixed that! Usually, it's easy to see - umbels look like parsley flowers, with all the stems radiating from a single point; corymb stems head out from the peduncle one by one. But it seems in early season flowers, the peduncle can be mere millimeters long and hidden from view, so that corymbs look to us like umbels. I was wondering if the bracts around the stem indicate anything. On corymbs, is each pedicel surrounded by bracts (is that the right word)? Here's a Rancho umbel. The second photo is from some upright white tree from the UBC Farm. I'd have guessed Sargentii, but does this arrangement indicate a corymb (and while we're at it, therefore not Sargentii - third photo is the set of trees; fourth is the original photo of the blossom example)?