You can find lots of good photos by Douglas Justice in his April 2021 in the Garden - UBC Botanical Garden blog. I posted the first ones he mentioned, Rhododendron praevernum and R. barbatum, last month at Mid-March, 2021 | UBC Botanical Garden Forums, so I got to do ones that were new to me today. I think this is R. pachytrichum, next to a very tall R. barbatum. This is not supposed to be new to me, but I have not learned the name at all yet. R. lutescens at Kingdon Ward Way (this isn't new to me - I recognized one all by myself in Stanley Park, having learned it here). This group is on Staunton north of Upper Asian Way. I think the mauvy-coloured flowers are the same species. Rhododendron principis must have the softest abaxial (leaf underside) surface of any plant. It didn't seem to rub off, so I wondered if that was indumentum, but it seems to be, according to Rhododendron principis - Trees and Shrubs Online, which says "lower surface covered with a white to fawn two-layered indumentum, the upper layer spongy, lanate-tomentose, composed of ramiform hairs, the lower compacted". I probably am not successful here in showing you how wonderful this feels. The flowers are a little past their prime, but that was irrelevant.