Lionheart (Acer palmatum 'Lion Heart' )

Lionheart is supposed to be the red leafed equivalent to Seiryu, the green upright dissectum, but I have not seen that; although it certainly has a red dissected leaf, it hasn’t nearly the vigor of Seiryu and altho it is not actually pendulous, it is more spreading than upright. But look at this photo taken today 11/30/11. really nice late color

Lima Gold (Acer palmatum 'Lima Gold' )

Lima Gold is a dwarf similar in form to Mikawa yatsubusa. The spring gold surrounded by the red seed starts is stunning.

Kurui jishi (Acer palmatum 'Kurui jishi' )

This cultivar has strongly incurved leaves and supposedly a vase shaped habit; but mine have a sort of drooping wide shape. The leaves are darker green than Okushimo which has a similar leaf form. zone 5.

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