
784 The American Naturalist. [September 
HEMLOCK AND PARSLEY. 
BY W. W. BAILEY. 
TE study of the order Umbelliferæ presents peculiar diffi- 
~ culties to the beginner, for the flowers are uniformly small, 
and strikingly similar throughout the large and very natural 
group. The family distinctions or features are quite pronounced 
and unmistakable, and it is the determination of the genera which 
presents obstacles, — serious, indeed, but not insurmountable. 
“ By their fruits shall ye know them.” 
The Umbelliferæ, as we see them here, are herbaceous, with- 
hollow, often striated stems, usually more or less divided leaves, 
and no stipules. Occasionally we meet a genus, like Eryngium 
or Hydrocotyle, with leaves merely toothed or lobed. The 
petioles are expanded into sheaths; hence the leaves wither on 
the stem. The flowers are usually arranged in simple or com- 
pound umbels, and the main and subordinate clusters may or may 
not be provided with involucres and involucels. To this mode of 
arrangement there are exceptions. In marsh-penny-wort (Hydro- 
cotyle) the umbels are in the axils of the leaves, and scarcely 
noticeable; in Eryngium and Sanicula they are in heads. 
The calyx is coherent with the two-celled ovary, and the border 
is either obsolete or much reduced. There are five petals inserted 
on the ovary, and external to a fleshy disk. Each petal has its 
tip inflexed, giving it an obcordate appearance. The common 
colors of the corolla are white, yellow, or some shade of blue. 
Alternating with the petals, and inserted with them, are the five 
stamens, 
The fruit, upon which so much stress is laid in the study. of 
the family, is compound, of two similar parts or carpels, each of 
which contains a seed. In ripening, the parts separate, and hang 
divergent from a hair-like prolongation of the receptacle known 
as the gynophore. Each half fruit (mericarp) is tipped by a 
persistent style, and marked by vertical ribs, between or under which 
_lie, in many genera, the oil-tubes or vittæ. These are -channels 

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