Some foggy days in London Town this week made me think back on the Frisco fogs I have known over the years. The traditional English pea-souper is a different beast to the California variety. The fogs of Blighty are the cold damp fogs of a cold climate whereas the fogs of the Bay Area drift in from the Pacific at the height of summer when the landscape is parched and arid. They are indeed chilly and moist but they burn off during the course of the day.
 When I was in SF over the summer I did a day hike with a couple of pals along some of the trails on the heights and slopes of the magisterial Mount Tamalpais which looms over the Bay. As the first photograph shows fog banks rolled over the yellowed grasses as we made our way. The ground was dry, too dry by now to sustain much in the way of wildflowers (of which there are many in spring). But a few persist.
 We came upon a stand of the pink flowered Tiburon Buckwheat (Erigonium luteolum var. caninum), endemic to this part of California but rare. Touching one of the flowers it was sopping wet like a sponge. I imagine it survives the months of drought by literally sucking moisture out of the air.    

 Rich yellows, deep browns and russet reds provide a spectacular finale to autumn then give way to the sombre tones of winter. None the less plenty of greenery remains to lighten the gloom.
 Case in point is Arum italicum marmoratum which puts out glossy arrow shaped leaves with marbled white veins and thrives in shady leaf litter. Actually I'm generally not fond of plants with variegated leaves. Plant breeders all too often utilise this trait with garish results but some species have a natural tendency to variegation altogether more pleasing on the eye.  
 It seems obscure whether marmoratum is a cultivated variety or a subspecies of A. italicum or perhaps it's both of these- a freely occurring hybrid that readily cross breeds with itself. Certainly the veining varies from pronounced to feint.
 It's reckoned to have been introduced to the UK from the continental Europe centuries ago. Our native Arum maculatum is widespread in similarly shady woods and hedgerows but has plain green leaves, sometimes with dark blotches but no marbling. 

 The back garden is full of leaves. That's good- damp and decaying leaves are one of the sensory delights of autumn.
 When I worked in the gardening trade I would spend much of November raking up fallen leaves to cart off the premises in plastic bags. In spring I would purchase plastic bags containing soil improver and haul them onto the premises. It's a living and well-tended gardens are charming in a way.
 Unfortunately a lot of gardening is based on the premise that nature is untidy, chaotic even. In fact nature is order on a colossal scale. The leaves fall, the soil improves!

 California dreaming on such a winter's day. On a particularly cold, wet, grey and dismal London day my thoughts drifted to memories of my hike through the Castle Crags Wilderness in July of this year, also hiking round Crater Lake in Oregon in July 2017 and Mount Shasta in June 2016, another NorCaL landmark. Temperatures in the high 30s, blue sky and bleaching sunlight seem like a dream compared to old London town.
 Then again news of the wildfires still raging across California gives me pause for thought. The haze in the first photo is not mist or some artistic filter; that day the air was pungent with smoke blowing downwind from a major wildfire burning 40 or 50 miles to the North. I'll write an entry on this subject in the near future because the volatility of these monumental landscapes is fundamental to appreciating them. 

 Walking through Greenwich Park on Sunday afternoon many of the trees were already bare but those still holding onto some of their leaves glowed with an intense luminosity as the sun began to wane. 

The last leaves of autumn are falling and a wintry chill is in the air...

 Roots and shoots. I wrote a couple of entries about seeds recently. The last one (30th. October) looked at the life cycle of a seed up to the point of germination. One of my flatmates is growing this avocado plant in the kitchen and it provides a good illustration of what comes next.
 What we can't see here is the first growth that takes place which is the emergence of the radicle (the embryonic root covered in fine root hairs to absorb water and minerals). The radicle is positively geotrophic i.e. it grows down. This is the consequence of cell division of the epicotyl which is at the base of the radicle and has the effect of anchoring the plant.
 Then comes the plumule (the embrionic shoot). It's negatively geotrophic; in other words it grows up! This results from the enlargement of the hypocotyl close to the base of the plumule.
  Thus the seed becomes a seedling and eventually a mature plant.