22 CHARACTERS OF BRITISH PLANTS. 
base of the stem as represented in English Botany, 348. 
The “ root of slénder elongate-clavate tapering fleshy 
tubercles" (Manual) probably refers to a middle period 
of development, .before the tubercles are fully formed ; 
while the words * root of elliptical-oblong" tubercles would 
apply to a more advanced stage. There is, however, a de- 
cided difference in the fruit of these plants; it being almost 
eylindrical in some specimens, and obovate or turbinate in 
others: though this distinction seems quite unconnected 
with the presence or absence of an involucrum. Nor, so 
far as my specimens go, am I able to connect it with any 
constant form of root or of root-leaves. 
Helosciadium nodiflorum (Koch) and H. repens (Koch).— 
It is so easy to find intermediate specimens, in which the 
characters assigned to these alleged species are variously 
crossed and combined, that there appears no good reason for 
keeping them distinct. In H. nodiflorum the umbel is rarely 
or never quite sessile, often on a peduncle of an inch long. 
The obtusely and subsequently serrate leaves occur both on 
the procumbent and on the creeping stems. 
Eryngium campestre (Linn.)—As there appears some dan- 
ger of this plant being “ split” into two book species, founded 
on slight differences in its radical and involucral leaves, it 
may be well to record the fact, that in my Devon specimen, 
equally as in a specimen from Jarrow, there are both sim- 
ple and spinous involucral leaves on the same plant. I have 
the radical leaves only from Jarrow: they are rather bipin- 
natifid than three-lobed, though something of an inter- 
mediate character. 
Tragopogon pratensis (Linn.) and T. minor (Fries. )—Their 
relative length of florets and involucrum is variable ; and since 
there appears to be no other clear distinction boten these 
plants, it is difficult to understand why they should be de- 
scribed as two species. To be consistent, they should rather 
be made into three than two species, according as the invo- 
lucrum is longer, shorter, or equal to the florets. 
Thrincia hirta (DC.)—The variety “dubia” is said to be 
