135 
obtuse than in the last. (Fig. 162.) — II. interrufta Ton*. Gray, 
FI. i. 599, in part. 
Texas to Arizona and California, extending also into Mexico. 
A species very closely related to the last. 
3. H. Canbyi C. & R. Bot. Gazette, xii. 108. Umbels 3 to 
9-nowered, generally proliferous; pedicels very short, but distinct: 
fruit slightly notched, a line long, and about two lines broad, much 
more flattened than in the preceding forms, dorsal and lateral ribs 
much more prominent, the former acutish. (Fig. 163.) H. 
unibellata^ var ? ambigtia Gray, Manual, 190. 
New Jersey to Maryland. 
Distributed in the older collections as a probable from of H.. vul- 
fjar i.'i L. 
The three foregoing species, with H. vulgarif^ of Europe, form a very 
natural group, closely resembling each other in the anatomical details of 
the fruit. H- violgaris is most nearly related in external appeai’ance to 
H. Canbyi, but differs in its smaller fruit more or less dotted with oil 
vesicles, its less flattened carpels, and less prominent dorsal and lateral 
ribs, thus intermediating between H. Canbyi and the first two species. 
There can be no doubt but that our three species are the Noi’th American 
representatives of H. vulgaHn. 
f t Fniit not notched ; incermediate ribs not corky {^filiform'). 
4. H. verticillata Thunberg, Diss. II. 415. t. 3. Umbels 
few-flowered, proliferous, forming an interrupted spike; pedicels 
very short or none: fruit a line long, to 2 lines broad, with 
dorsal and lateral ribs very prominent, the former acute. (Fig. 
164.) — //. interrufta Muhl. Cat. 10. 
Massachusetts to Florida and Texas; extending into Arizona {Lemmon), 
Utah {Palmer), and near San Diego, California iOrcutt); also in Mexico. 
* ^ Fruit zvith pericarp uniformly corky thickened and ribs 
all filiform: leaves not peltate: peduncles much shorter than 
petioles. 
f Fruit small ( f. ^ U lif^<^s broad), without secondary 
ribs or reticulations’, iuvolucral bracts small or zvanting. 
5. H. Americana L. Spec. 234. Stems filiform, branching 
and creeping, often bearing small fusiform tubers: leaves thin, 
round-reniform, crenate-lobed and lobes crenate, shining: few- 
flowered umbels axillary and almost sessile: fruit to line 
