Yunnan, kingdom of flowers ruled by oaks

Last month I was in northern Yunnan - around Lijiang and Shangri-la (Zhongdian) - with a group of 20 (mostly) plant enthusiasts, climbing (well, by bus and relatively gentle walking) to over 3600 metres above sea level in search of plants well known from our gardens in Australia as well as many I'd never seen before.

I've posted these already on Instagram but I wanted to provide a little more background to some. 

Let's start with oaks, a family favourite over recent years (Three Worlds Oak is due out in the UK on 1 September and should be in Australia by December...) and given this is the Northern Hemisphere there is almost always one growing in a nearby forest. (Also firs, spruces and other conifers but I could only see oaks...)

In this case, the oaks are mostly tall forest trees once classified in a separate genus called Cyclobalanopsis and commonly called ring-cupped oaks, or stunted shrubs (rarely small trees) related to the holly/holm oaks of the Mediterranean. Oh, and a few 'white oaks' such as this corky-barked one, which closely resembles Mongolian oak, Quercus mongolica, a species not reported from Yunnan (so probably another species in the same group, or planted...).

Quercus mongolica

But I was besotted by the holly/holm oak relatives. These get to the highest altitudes of any oaks in the world, and like their cousins in the dehesa of Spain (and montado of Portugal) they are well adapted to extreme climates.

This next one was often a small shrub, kept low by grazing or weather, but sometimes managed to reach a few metres high. The new Shangri-la Alpine Botanical Garden was calling this species Quercus monimotricha, although I thought a similar looking plant in the foothills of Jade Dragon Mountain near Lijiang was more likely Quercus spinosa. I gather they are rather similar.

Quercus monimotricha

Another of the holm/holly oak group was more often a small tree, leaves spiny edged when young but entire in older specimens. A population near the field station of Lijiang Alpine Botanical Garden was being called Quercus semecarpifolia, although it might also be Quercus senescens. This identification was based on a brief exchange in Mandarin via my phone translater. 

Quercus semecarpifolia

They may have been other species masquerading as these two, depending on the habitat and altitude, but I'm not up for a full interrogation of their taxonomy based on my passing acquaintance over a few days. No matter what their names, they were impressive oaks. Not tall and grand in stature, but rugged and nuggety. Their persistent leaves were tough (sclerophyllous) and at least when young, with sharply spiny margins. Plus, they had lovely tassles of male flowers, something I had read (and written) about, as well as red-toned new growth. Plenty to enjoy.

Alongside the immensely attractive oaks were plants with more voluminous flowers, evolved to attract insect pollinators rather than to have the pollen shaken out of them by wind. Here are a few of the more distinctive ones.

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These purple and yellow flowered species of Roscoea, in the ginger family (Zingiberaceae), look initially very like an orchid or an iris - you can see both similarities in the following pictures. The genus includes 22 species, with eight found only in China and all of them at high altitudes around the Himalaya region. 

The flowers have a deep 'floral tube' behind that front, lip-like 'petal' (actually a sterile, petal-like stamen I gather), shown in some species to be an adaptation for pollinating insects with a long proboscis (tongue) such as moths. Other Roscoea species, however, may be pollinated by beetles.

This next one is a legume, with chocolaty-purple pea flowers, called Thermopsis barbata. The genus of 30 or so species extends through to North America, where it typically has yellow flowers and is sometimes called false lupin.

This striking plant, called black pea in western horticulture, popped up here and there in a cleared roadside paddock above 3000 metres. A perennial with a woody root and short stem, it too is found only around the Himalaya, from India to China. It is also one of very few flowers that can be described as 'black', or almost so.

Nearby, a couple of yellow-flowered euphorbia species (one included here) and a yellow-flowered pimelea relative (possibly Stellera chamaejasme, with its species name meaning 'ground jasmine'). Both at least seasonally toxic to stock.

Those little blue dots in the background of the alleged stellera are, as the next picture shows, pretty blue gentians.

Euphorbia

Stellera, perhaps

Gentiana

Finally, a sweet little pea, Tibetia himalaica I think. A name that says it all but let me add that is uncommon across its range from India to China, above 3300 metres.

There were plenty more plants in flower of course. Not so many rhododendrons, and no camellias (wrong time of year), but then we all know what they look like. Still, in case you've forgotten, here is a 'rhododendron' and an 'azalea' from the mountains near Shangri-la.

Note: the picture of Quercus semecarpifolia with catkins of male flowers was kindly provide by Rowena Slater, and I was leading a Jon Baines Tour, 'Botanical Histories in the Kingdom of Flowers - Yunnan, southwest China'.