The magnolia seem to favour certain pockets among the forested ridges as do their cousins, the michaelia with their large creamy yellow flowers.
Lower down the mountains there is daphne growing under the taller trees. The Bhutanese make handmade paper with its bark - studding the paper with flowers and leaves; sometimes even with decorative arrangements of marijuana leaves, which grow wild here.
Soon there will be no yaks under the rhododendrons because as the weather continues to warm up the yak herders will take their animals high into the summer pastures.
But for now, they browse happily among the spring flowers or stand belly-deep in the dwarf bamboo, a favourite yak food.
At this time of year even the coniferous forests on Bhutan's mountains look fresh, rejuvenated - in moist gullies blue pine and spruce are festooned with lichens that waft gently in the winds.
Where the forest has been cleared (and in Bhutan more than 70 per cent of land is forested - and this figure will neve be allowed to drop below 60 per cent) Bhutanese farmers are preparing for the spring growing season. Potatoes are being planted, animal manure is being spread on terraced rice padi fields and grains are being sown.
Already the first of the new season's "crops" are for sale.
Ladies are sitting beside the road with woven baskets full of newly unfurled fern tips. When cooked they have a delicate flavour, their deep green spirals contrasting well with another local speciality - whole green chillies cooked in cheese sauce.
Eating the latter is a sure way of transporting one's taste buds from spring to fiery summer.