Fronds eight to eighteen inches long, lanceolate-oblong, tripinnate.    From Wordnik.com.  [The Fern Lover's Companion A Guide for the Northeastern States and Canada] Reference

A tripinnate form of this variety discovered at Concord, Mass., by Henry.    From Wordnik.com.  [The Fern Lover's Companion A Guide for the Northeastern States and Canada] Reference

Fronds two to six inches long, triangular-ovate, acute, broadest at the base, tripinnate.    From Wordnik.com.  [The Fern Lover's Companion A Guide for the Northeastern States and Canada] Reference

Stipes three to nine inches tall, blades one to three inches, triangular-ovate, pinnate at the summit, and tripinnate below.    From Wordnik.com.  [The Fern Lover's Companion A Guide for the Northeastern States and Canada] Reference

From a systematic point of view these leaves indicate the origin of the water-parsnips from ordinary umbellifers, which generally have bi - and tripinnate leaves.    From Wordnik.com.  [Species and Varieties, Their Origin by Mutation] Reference

3 to 6 feet high, round, smooth, and marked with brownish purple spots; lower leaves tripinnate; upper, bipinnate.    From Wordnik.com.  [General directions for collecting and drying medicinal substances of the vegetable kingdom : list and description of indigenous plants, etc., their medicinal properties, forms of administration, and doses,] Reference

Fronds ovate-oblong, often tripinnate.    From Wordnik.com.  [The Fern Lover's Companion A Guide for the Northeastern States and Canada] Reference