Kurabu yama (Acer palmatum 'Kurabu yama' )

Kurabu yama is one of the lesser known palmatums; it is definitely a tree to maybe 15′; the leaves are deeply divided and come out a strange auburn color in spring changing to green and finally in fall to a wonderful show of orange, gold and scarlet.

Krazy Krinkle (Acer palmatum 'Krazy Krinkle' )

Krazy Krinkle is an apt if undignified name for this maple. The leaves are bright green and ruffled much like Shishigashira, only larger; the tree is vigorous and upright. Zone 6. This photo from Michael Healy doesn’t quite get enough of the skrunchiness of the leaves, in my opinion.

Koto no ito (Acer palmatum 'Koto no ito' )

One of the smallest and most threadleaf of the threadleaves. Summer color is light green; fall color is orange. zone 6

Koshibori nishiki (Acer palmatum 'Koshibori nishiki' )

This is considered a variegated maple but sometimes it is really hard to see as it is more a dusting of white or yellow. It will get maybe 6′ in ten years.

Kinran (Acer palmatum 'Kinran' )

Kinran is a short wide tree (8′ in ten years) well suited for pot culture as it takes well to shaping. The leaves are bronzy in spirng with prominent veining, deeply divided and lacy looking. The veining persists throughout the color changes of summer and fall culminating in striking gold on red.

Ki hachijo (Acer palmatum 'Ki hachijo' )

This is my favorite green Japanese maple because the leaves are a bright light green all summer, and the serrations on the leaves give the tree, which grows easily and stoutly to about 20′, a lacy look. The fall color is many-hued and always excellent. zone 6

Katsura (Acer palmatum 'Katsura' )

The distinctive color of this tree all summer long makes it desirable for any garden. Supposedly it can get 30′, but my reasonably mature specimen is 15′. It is densely branched with thin twigs. Fall color is orange yellow. My tree seems to always have a halo; I think it is my favorite. zone 6

Kashima (Acer palmatum 'Kashima' )

Kashima is a green dwarf often used for bonsai; if unfertilized the leaves are tiny, but with plenty of water and fertilizer, this can be a strong growing shrub. Fall photo from Winch.

Kasagiyama (Acer palmatum 'Kasagiyama' )

The color on this cultivar is very ususual as there is a sort of brick-like mottling as the leaves age. The tree stays short, no more than about 12 feet, but it can be almost that wide. zone6