42 
no involucre, and involucels of few short subulate bractlets; rays 1 
to 3 inches long; pedicels 5 to 8 lines long: fruit oblong, glabrous, 
3 lines long; dorsal and intermediate ribs very prominent, lateral 
wings thin, about half as broad as body: oil-tubes 25 to 30 and 
continuous, 8 to 10 of them on the commissural side: seed-face 
plane. (Fig. 18 .) — Archangelica atropurpurea Hoffm. Um- 
bel. 161. 
Low river banks, from Labrador to Delaware, and westward to Illinois 
and Minnesota. Fi. June. ^ 
A. LUCiDA L. is referred to Canada by Cornuti, upon whose 
authority alone it stands as a North American species. It has long 
been cultivated in Europe, but its existence as a member of our 
flora is so very improbable that we do not include it. See Ton*. 
& Grav, El. i. 621. 
f 
A. VERTiciLLATA Hook. is a very uncertain species, and 
judging from the description given (which is the only information 
accessible) Mr. Watson thinks it probably belongs to some other 
genus. See Watson Proc. Am. Acad. xvii. 374. 
8. SELINUM Linn. Gen. n. 337. — Tall stout branching per- 
ennials, with pinnately decompound leaves, few-leaved involucre, 
involucels of numerous narrow or broad bractlets, and white 
flowers. 
This genus is considered hard to distinguish from Ligusticum, hut 
with our own species there is no such trouble . Ligusticum is character- 
ized by its fruit having equal ribs, numerous small oil-tubes, and prominent 
conical stylopodium, as Avell as by its leaves being always ternate in their 
primary divisions. Selinum, on the other hand, has fruit more winged, the 
lateral wings being the broadest, prominent solitary oil-tubes, usually de- 
pressed stylopodium, and mostly pinnately compound leaves. The genus 
seems more nearly allied to Angelica, through'lsuch a species as Selinum 
Hookeri. The important distinctions are that the dorsal and lateral 
ribs of Selinum are decidedly and equally winged, sometimes nearly as 
much so as the laterals; while the dorsal ribs of Angelica are not at ali 
Avinged, except such irregular winging as occurs in A. Curtisii- The 
leaves of Selinum are, as a rule, pinnate; while those of Angelica (with the 
single exception of A> pinnata, which can hardly be considered a typical 
Angelica) are ternate, at least in their primary divisions. In Angelica the 
bractlets, if any, are small and very narrow; Avhile in Selinum they are 
frequently prominent and sometimes broad. Selinum usually has, also, a 
less flattened carpel, and always strictly solitary oil-tubes. 
