Douglas Justice was too good to us this month, featuring tree-sized rhododendrons in his blog: April 2019 in the Garden | UBC Botanical Garden. Really, how hard is it to find huge trees covered with flowers? I only photographed a few of them, as I was with a very enthusiastic photographer and we didn't get all that far. I hope Michael will post some of his photos here. In the meantime, in April, you can click the link to Garden Explorer in the blog and see lots of photos. After April, you can still see lots of photos, but you will have to enter the plant names. In April, the dropdown offers you the April tour. Here is Rhododendron arboreum, one of the first rhododendrons we saw. It is so impressive, with flower colour varying from white to dark pink. Douglas included my favourite - Rhododendron barbatum. I just like it for the "beards", but the flower colour is popular. It looks kind-of Christmas tree-like when the sun is on all those flowers. I have been trying to photograph the bark for years.
The Larch ( Larix Otaninii Args.139 [edited by wcutler: name is Larix potaninii, see below] is actually outside the entrance to the Gardens. It can be found towards the car park in the NW corner. The new growth is silky soft. If you look closely at the first rhodo photo ( Rhododendron barbatum ) you'll see the barbs in the centre of new leaves. the second rhododendron photo is from the same species.
To the left of the R. barbatum in the first posting is an almost equally large Rhododendron oreodoxa. I might be too late in posting this already - the ground was covered in blossoms, yet the tree was still very pink.
Here are a few more from April 26. There are a LOT of showy rhododendrons now. You can stand anywhere and gawk. Here is Rhododendron rubiginosum 'Wakehurst'. It definitely qualifies as tree-like. Just past it is R. rigidum. There were not many flowers to photograph on this Rhododendron arboreum seedling [edited - see below, it's R. arizelum] , and they were either too far to get in focus, or past their prime. I liked the texture on the flowers, but it was the leaves that attracted me anyway.
Here's one more from the blog, seen on May 6 - Rhododendron falconeri. I have never seen it (or named a photo of it) with the "vestiture of dense brown hairs" completely covering it; once the leaves open, they no longer have the hairs on the upper surface.
Rhododendron calophytum was also mentioned - here is R. calophytum var. openshawianum, on May 6. I didn't get a habit photo - got caught up the details, like the red bracts that first attracted me to it, and the cinnamon-coloured bark.
Presumably the larch is Larix potaninii (note spelling) from W. China. The "arboreum seedling" has characters of Subsection Falconera rather than Subsection Arborea. Maybe it is actually labelled arizelum seedling, and you read misread the label or typed the name wrongly here, by mistake. It certainly looks like that species (R. arizelum).
Did I say how glad I am you're back? My photo of the label was so out of focus that I did indeed misread it.
Thanks, @Ron B. I have noted that above. I forgot that Michael included that in this rhododendron thread.