Geranium

Geranium aristatum £4
A subtly beautiful Balkan relative of G. phaeum, with the same back-swept petals, but this time in pale lilac heavily marked much darker. Greyish foliage, dying away in winter. 60cm.
Geranium 'Blue Cloud' £4.50
Blue geraniums are too many and too similar. This is quite distinctive with pale blue flowers, veined crimson over a long season; height 50cm.
Geranium 'Blue Sunrise' £4
Young leaves in spring are bright yellow, and continue yellow tinged into early summer. Mid-size blue flowers.
Geranium 'Buckland Beauty' £4
Low growing, but not small, with bronzed leaves and aggressive deep magenta flowers of endressii type. It is a beauty, not another of those mingy, murky-leaved things.
Geranium x cantabrigiense 'Berggarten' £4
Unusually in this ground covering hybrid, the flowers are a solid pink, not a pale or veiny colour.
Geranium 'Coombland White' £4
Compact mound of grey foliage, with white, upward facing flowers in summer. lambertii x traversii, I believe: a white counterpart to 'Joy'.
Geranium 'Dusky Crûg' £4
Has more go to it than the usual brown leaved ones, having oxonianum as a parent. Low, with good sized soft pink flowers. Sun, drainage.
Geranium 'Elworthy Eyecatcher' £5
Good sized shiny light magenta flowers over a very long season. 60cm ish. A good plant, still uncommon. Thanks to Jenny and Mike 'Elworthy Cottage' Spiller.
Geranium himalayense 'Derrick Cook' £4.50
A very good form of this low clumper. Large flowers are ice blue, white from any distance.
Geranium 'Kanahitobanawa' £4
Presumably G. x oxonianum 'Thurstonianum' x G. psilostemon. It has large, vivid magenta-purple flowers over a very long season (it's sterile) with narrow petals giving a starry effect and clearly showing the green sepals between them. The petals are dark veined with slightly toothed ends (less extremely so than in 'Thurstonianum') and the anthers are sometimes a little petaloid. In habit it's a big dome former for the border, intermediate between the parents, neither sprawly as  oxonianum, nor stiff and gaunt as psilostemon. Our plant, our daft name. We're allowed to say that. You just have to try to pronounce it.
Geranium koraiense £4
Low growing and pink.
Geranium libani x ibericum £4
In effect, an ibericum with dark, inky violet flowers. Leaves often age red.
Geranium 'Solitaire' £4
Like its parents, a summer dormant plant with attractive leaves low to the ground in winter, and large clear blue flowers on 40cm stems in spring, but more vigorous and quicker growing than either. Goes on flowering for longer, too. Previously (and correctly) listed as libani x peloponnesiacum, but Alan Bremner who raised it has now named it. Why 'Solitaire'? 'First thing that came into my head' he claims.
Geranium macrorrhizum 'Lohfelden' £4
Pink on white striped petals in this form of the classic aromatic perennial for drier shade.
Geranium maculatum 'Elizabeth Ann' £4
Brown tinted foliage and pale pink flowers in spring. Height 30cm or so.
Geranium maculatum 'Silver Buttons' £4.50
Essentially a white maculatum with fringed petals. Rare, and we can't trace its origin. Thanks to John Newbold.
Geranium nodosum 'Julie's Velvet' £4
A great species, quickly forming low (to 30cm) clumps with rather shiny green leaves and nice purple flowers in summer, tolerating rather dry shade. If you don't grow 'Whiteleaf', 'Svelte Lilac' or 'Swish Purple', this is probably the cultivar you want, richer in colour than any of those, but still with a paler margin to the petal. If you do, well, it's not that different...
Geranium 'Orion' AGM £4
Grown on the recommendation of the Wynn-Joneses of Crûg Farm, this is now our favourite of the many blue pratense-type plants. Big flowers of a clear deepish blue. 50cm or so.
Geranium phaeum 'Blue Shadow' £4.50
About as blue as phaeum gets.
Geranium phaeum 'Margaret Wilson' £4.50
Very distinctive fine, creamy white net-variegation across the leaf surface, violet flowers. It's the leaves you want, so cut the flower stems back right after flowering, or even before. Rumour had it that the variegation comes through in seedlings, but missed out the word 'sometimes'.
Geranium phaeum 'Our Pat' AGM £4.50
This large flowered, 60cm tall clone of the classic purple-black flowered geranium, selected by Robin Moss, has that indefineable something which makes a good plant superb. I hear rumours that the RHS committee judging the trials voted unanimously for the AGM.
Geranium phaeum 'Séricourt' £4.50
A French variety with leaves clear yellow in spring. The flowers are red-brown.
Geranium pratense 'Plenum Album' £4.50
The third, and by far the rarest, of the double forms of pratense, with many, new 10p sized double white flowers. More picky than the other forms of this species, thriving in a moist and fertile but well-drained soil, in sun or partial shade. Very, very slow to propagate, so seldom offered by nurseries. Just a few divisions again.
Geranium pratense 'Purple Heron' £3.50
Dark, dark purple foliage; deep violet flowers in summer on a compact plant to 45cm. A clone of the highly prized 'Midnight Reiter' which is variable from seed and painfully slow to propagate by division - but we divide it anyway. Small, and slow growing.
Geranium 'Prelude' £4
It looks like a short sylvaticum with unusually small but plentiful lilac flowers. Different.
Geranium pyrenaicum 'Bill Wallis' £3.50
Loveable self seeding sprawly job which drapes itself pleasantly through other vegetation. The deeper purply blue form  with red stems.
Geranium x riversleanum 'Jean Armour' £4
You might not want to replace dear old 'Mavis Simpson', but if you don't have Mavis, I'd go for Jean instead.
Geranium 'Stephanie' £4
A recent hybrid, pelopponesiacum x renardii. Summer dormant-ish, with flowers like the former parent and leaves midway between the two. Very floriferous and desirable.
Geranium soboliferum Cally strain £4
Flowers a solid, rich pink from later in summer than most, through to September. 30cm tall with narrowly lobed leaves. From Michael 'Cally' Wickenden's Russian collection.
Geranium sylvaticum 'Amy Doncaster' £4
Every gardener of taste eventually discovers and comes to love it - the best sylvaticum of all, and one of the finest of all geraniums (three extravagant claims in one sentence, but sincerely made). True blue, white-eyed flowers.
Geranium 'Tiny Monster' £4
Hot hybrid, with large rich red-purple flowers and the dark green leaves of G. sanguineum on a plant which, while almost mat forming in its first year or two, rears its fearsome head once a solid clump has built up. Long flowering season. There's not much tiny about it...