14 JIOliPHOLOGY; DIAGNOSIS.
the testa is vei-y lax. In colour the testa T»rie> from black (J. /urftracn) slate .^rev
( J . yiifem), dark brown (P. rUnmtlmd^), or rusly brown ( J . dphomutlu,), to pale tawny
(F. me,ah,tlu), or pale straw colonr (P. Odcri). But colour is not, and will probably
neyer become, a character of great practical ™lne in distinguishing ,ha seeds of diflerent
species of P e d i M , because the differences are so often mere variations of shade not
equally appreciated by all observers; because these shades appear to become li^lrter as
the seeds ripen; and finally, because there is no guarantee thai the seeds are not
sometimes at least, altered in colonr while the specimens arc being dried. The most
useful characters afforded by the seeds are those derived from the nature and the
markings of the testa. Sometimes tl,is is thin and closely adpressed to the albumen
a . Imaiflom), and then the surface is only marked by slight longitudinal striai: at other
times It IS much more erfensive, tlie albumen not nearly filling it, and is then la.t
and deeply pitted. All possible intermediate conditions occnr, and these are best
expressed in terms of the pitting which results, and which is the most prominent
feature of the seed.' There is in most cases a distinct appearance of longitudinal
ridging that runs meridionally from apex to base. The ridges are only an acce°ntuation
of the condition producing the striation that exists when the testa is closely adpressed
•to the albumen, but m addition to this the furrows between are crossed by transverse
iidglcts that complete the periphery of the characteristic pits. Where these transverse
ndglets ara^ narrower and less in relief than the meridional ridges-and this is the
n.sual condition- a pitted and furroived appearance go together. But where the trans
verse ridges equal the meridional ones in width and height, a net-like appearance is
imparted to the testa, and this becomes more and more apparent when the testa is
obviously more extensive in relation to the albumeii {P. hrnvifoUa, ienudata), while not
infreque..tly whore the testa is very extensive indeed {P. trulmghna. Oiarbi) the peri
phcry of the pits becomes irregularly hexagonal and the surface assumes a honeycombed
appearance. As a rule, the matldngs are uniform throughout the testa, but sometimes
(P- peaiinala, complonicefolia, dolickorrhiza^ the funicular aspect of the seed is thus
irregularly (and generally very irregularly) honeycombed, while the remainder of the
surface is ridged and pitted in a regular manner. And sometimes where the testa is
very loose, the ridged arrangement still persists {P. aloichani^a) and produces a oiHed
appearance; the meridional gill-like ridges have transverse pit-forming ridglets on both ides
The albumen is firm, and the embryo, which is straight, occupies a mesial cavity in
the upper portion of its mass. Usually the embryo is from one-fonrth to „ne-third the
length of the albumen, rarely (P. „cna^tk.) exceeding one-half. The radicle points
Upwards; the semi-cylindric cotyledons in the opposite direction.
CHAPTER III.—DIAG-NOSIS AND CLASSIFICATION OP SPECIES.
IK diagnosing the species of Pedicularis, characters afforded by habit are of compara.
lively small value. This is partly because habit varies greatly within the limits of
individual species, partly because quite distinct species very frequently display remarkable
identity of habit. This identity is not, however, necessarily confincd to vegetative
organs alone, as is the case with P. lachmghsm and P. Parriji; P. m,jUi and P. verti.
eillata; P. msgakntlm and P. chiacmis, but may extend to floral characters and this to
' Cf. plate 36 and plate 37 for csamplea of tlio conilitiona deUilcd io tlie
VALUE OF DIAGNOSTIC CHARACTERS. 1.5
such an extent that at length only a single character may be left whereby a diagnosis
between two, sometimes even more than two, species can be effected. Only a few of
the many examples of this need be mentioned:-J. Oedtri can only be diagnosed from
P Jlommaa (unless seeds be available} by the hairs on its anterior filaments; P. Clarhei
from P. Pmmiiina (unless the colour of the flower bo noted) by the presence of a beak
to the corolla; P. corymhosn from P . crtmla on the one hand by the absence of a beak,
and from P. zetjUnim on the other by the much longer hood; P. rhmanthoid.es from
P . tiphonantlm by its calyx being 5- not 3-tootlied and by the apex of the beak of its corolla
being entire; while P. ¡iplmiatha itself is only with certainty separable from P . lon¡,IJlom
(if the colour of the corolla is not noted) by the absence of hairs from its posterior
filaments and the presence of a distinct tooth on the margin of the hood. Careful
analysis of the floral structure in every gathering is therefore absolutely essential for
accurate diagnosis.
The opposite condition, with considerable difference of habit and great similarity of
floral structure, is rare in this genus. Still instances do occur, and those of P. jigcnanllm
a n d P . Oederi, P. shiifrct and P. amt, P. Oimmimna and P. Umria., P. Odlettii anil
P . seijlmica, may be mentioned. The calyx affords less useful characters than the corolla
or the stamens, partly for the reason given above, partly because it is somewhat more
variable within specific limits. There do, however, occur instances where calycine
characters are of high value. One of these, pointed out by Sir J, D. Hooker, is the
case of P . BiwesiU Another excellent example is furnished by P. Pantlingii, which is at
once distinguished from the otherwise very similar P. furfuraaea by its uncleft calyx. A
parallel instance among European species is the case of P. foliasa and P. sumam.
The same thing is true of the gynascium, less, however, because of the constancy of
its characters than because its modifications are usually accompanied by greater differences
in the other parts of the flower. This remains largely true of the fruit. There are
indeed some instances where the capsule or the seeds afford excellent diagnostic
characters:—the seeds of P. fiammea, as Dr. Lange has pointed out, are as distinguishable
from those of P. Oederi as are the stamens; the characters of the seeds of P. Roijlei make
it impossible to merge that plant in P. verticillata as Mr. Bentham proposes, whatever
elasticity be given to the limits of the Linnean species; and P. Wallickii differs even
more markedly from P. asplenifolia, to which Mr. Benlham has referred it, by its
capsule and its seeds than by its habit and its flowers. Another case -where the evidence
from the fruit is unmistakeable is P. Ion//(flora, -which cannot be confounded -with P.
siplionantha at the same stage oven if the habit, leaves, localit)-, date of collection, and
collector be identical, o-wing to a double curvature of the lower edge of its capsule -which
the capsule of P. sipkonantha wants, and to the absence of that pitting of the testa -which
the seeds of P. siphonantka exhibit. But the general rule is the reverse of this; where
there is identity of habit between two or more species accompanied by a greater or less
repetition of floral characters, the condition is even more marked in the capsule and the
B^eds than in the calyx. Among the must striking examples of this are P. carnosa,
P. corymhosa, ami P. zeylnnica, the cipsulcs and seeds of which are practically indistinguishable
; P. pcctlnata, P. pyraniidata, and P. teiiuirostris afford an equally instructive
instance.
It is then sufficiently clear chat in this genus only floral cliaracters can be relied on
in diagnosing nearly allied forms, and repeated and careful analysis of the flower in large
suites of Specimens is necessary for a just appreciation of the limits of species even if