Last week, we covered shunran (spring orchid). Shunran and keiran are very similar to each other, and in paintings, they are virtually indistinguishable except that shunran have only one blossom per stalk while keiran have several. I found it difficult to find pictures by historical Japanese artists on the web that feature orchids as the main subject until I came upon Nakayabashi Chikutō (1776-1853) (real name Narimasa). Chikutō favored the nanga (southern school) style and studied with Uragami Shunkin (1779-1846) with whom he published an illustrated book titled Gado kongosho (roughly: Heavenly Art of Painting). He wrote other art books on his own in addition to works of Confucian-based political philosophy and on Japanese classical literature.  There were groups of artists in Japan generally referred to as literati painters. I'm not sure, but I think that both Chikutō and Shunkin could be classified among them.

Here is one of Chikutō's keiran paintings.

The following keiran paintings came from a book by Chikutō devoted to the shikunshi subjects.

Shunran and keiran are orchids that culture Japanese identifies with. Yōran is a term that generally refers to other types of orchids, those mostly from other countries. There are a great variety of orchids around the world. 

Here are pictures just a few different species of orchids: