4 MOEPilOLOGY.
them (P. WalUchii). And in the species with thickened underground rhizomes that emit
flagella which give out fibrous rootlets and are prolonged upwards into apparently
annual stems {P. ti-ichoglossa, Chrliei, Prainiana) the radical loaves are evanescent. The
eauline leaves may b© few ia number, and then may resemble the radical leaves
(P. WalUchii], or be markedly unlike them {P. lachnoglossa). But usually the eauline
leaves are somewhat numerous, difieriug from the radical leaves mainly in being more
shortly petioled or altogether sessile and in having smaller laminaj. The transition as u
general rule is gradual where the species has alternate leaves, more abrupt if the leaves
be verticillate. But the transition may be abrupt where the leaves are alternate (P. lachnoglossa),
or gradual where they are whorled (P. rex). The length of the petiole is very
variable, sometimes it is slightly winged (P. alaschanica), very rarely much expanded so
that adjacent petioles become connate iu a memljranous ochreate sheath (P. rex). Very
often all the eauline leaves are sessile; the radical leaves may also be sessile (P. Clarlcei),
but this is extremely rare. In alternate-leaved species the lamina is usually lanceolate,
less often ovate (P. Collettii), while in species with opposite or whorled leaves the lamina
is of toner ovate than lanceolate (P. Eeydei). Though the margin is sometimes no more
than crenate (P. hella, carnosa), it is never in Indian species quite entire:^ more generally
the lamina is pinnatifid to partite; often it is twice pinnate, sometimes even thi-ice divided
(P. excelsa, Kingii). The extent of division diminishes as the lamina itself decreases in
size towards the apex of the stem.
The floral leaves may be only distinguishable, if distinguishable at all, from the'
eauline in size, in which case the flowers are merely axillary (P. fragilis, flezuosa, gibhera).
This is most usual in species with verticillate leaves. These floral leaves are then
generally smaller than the eauline; sometimes, however (P. flexuosa), they are of the
same size, rarely (P. denudata) the lower floral leaves are distinctly larger. But at times
in verticillate-leaved species, and usually in those with alternate leaves, the floral leaves
are modified into distinct bracts. In a few cases the transition to the bract region is
sudden (P. excelsa)-, as a rule it is gradual, and the lowest flowers occur in the axils of
what are only smaller eauline loaves. Bracts vary from ovate to lanceolate, with
margins serrate throughout (P. lachnoglossa), serrate only at the apex (P. trichoglossa),
or entii-e (P. tenuirostris) •, are usually sessile and represent only a modified lamina,
but are sometimes distinctly petioled (P. excelsa), and occasionally represent mainly a
modified petiole with only the rudiment of a lamina left at the tip (P. Oederi\
The flowers may be sessile or sub-sessile and the inflorescence sub-capitate or subspicate,
or distinctly pedicelled and the inflorescence racemose. When this is accompanied
by a loosely branching stem (P. gracilis, Kingii) the inflorescence becomes paniculate.
When pedicels are present the flowers are usually erect; sometimes (P. curvipes, resiipinaiu)
they are deflexed.
The flowers as a rule open centripefaliy, but it is by no moans unusual for those in
the lower axils to open later than the rest, as exceptions (P. dolichorrhiza, villosa), or as
a rule (SIPHONANTU^ generally). In the former case it is clearly not an instance of
centrifugal opening; in the latter it is by no means certain. The condition is constant
among the SIPHONANTHJE, and the evidence from herbarium material will be examined in
connection with the subject of sestivation, but careful field observation is necessary in
order to clear up the point. There are, however, frequent examples in high Alpine
' Tlie leaves ia two species—both American (P. anrjuitifvlia, 2ivKe!lii)—!iTe unduidcU.
sistence. As
/ith narrow-based
INPLOEESCENCE-COROLLA.
specimens of an exceptional, but yet distinct, centrifugal opening (P. cheilanthi/oUa) and
a centrifugal inflorescence is constantly present in, and is highly charactenstic of, the
Arctic group Ilirsutoe. i * /D
The calyx oomists of » tube which nmy be ovate (P. Elw,m), can,paBulate (P.
„mma) oylindiio (P. FcrotUtii), or subbflated (P. Wattichii), and of teeth which may be
iiuute IP «mrtmioefMa), but arc generally distinct, and then are either oblong or
triangular with a broad base, or ovate with a narrow base. The tube var.es in consistence
from thinly membranous (P. rex), or membranous (P. fraijilv,), to herbaceous
iP gmnrn, or thickly herbaceous (P. irfi«), and may sometimes even be sub-coriaceous
(P mUgrifolid). In a few cases tube and teeth are of the same
rale in calyces with wido-based teeth the margin, and m those
teeth the whole toolh, is of firmer consistence than the tube. ^
The tube is always longitudinally nerved; five strong mam nerves pass upwards into
the calyx teeth with usually five slender intermediate nerves that fork near the linibus
into marginal nervules for two adjacent teeth. As a rare occurrence the,se secondary
nerves may all be absent, but as a rule where the upper tooth is weak the upper mam
nerve is of the same thickness as the adjacent secondary nerves, while when the upper
tooth altogether disappears and the calyx is 2-dmtate, these adjacent secondary nerves
are not traceable, and the posterior nerve may either pass entirely mto one lateral tooth
( P rex), or more usually may fork into the two lateral teeth (P. moss) . The longitudinal
nerves may be unbranclied (P. rex), but usually those that pass directly into the teeth
give oft lateral nervules that may be confined to the teeth only (P. va-tkOkiia), or
extend throughout the upper third or half of the tube (the most nsual condition), sometimes
even to the base of the tube (P. MkUrrhha). The normal number of teeth is
five, but the upper tooth, except in a small number of species with triangular teeth, is
distinctly smaller and less incised than the other four. Of the remainder the two nearer
the upper tooth are almost always distinctly larger than the anterior pair. But often
there are only three teeth (P. sifhonanilm, lomjifior"), m which case the two lateral pairs
are confluent, and sometimes only two (P. carmsa, ColUttii, eurvipes) from the further
abortion of the naturally weaker upper tooth, or very rarely (as in the already quoted
case of P. rex) from the absorption of the upper tooth in one or other of the lateral
ones. The lateral nervules of triangular or oblong teeth anastomose with the marginal
branches derived from the forking secondary nerves ; the lateral nervules of narrow-based
ovate teeth are disposed like the nerves of a small leaf or bract. The length of the
teeth relatively to the calyx tube may vary considerably in the same species {P. Jmornuta),
but the proportions of the teeth to each other remain very constant. But it has to be
noted that in normally 5-toothed species the lateral pairs of teeth on one side or on
both may be conjoined (P. Elwesii, megalantha), while similarly the lateral teeth of
normally 3-or 2-toothed species (P. carmsa, Imgifiora) may on one side or on both be
divided. Besides being toothed, the liinbus is usually cleft in front, occasionally to the
base { P . rex), sometimes | to | of its depth (P. Elmiii, furfuracea), but usually only from
^ to I, and occasionally the limbus is not perceptibly cleft (P. gracilis, gruina). In
2-dentate species it is cleft also, though less extensively, behind. The margins of lanceolate
or oblong teeth moy be enthe, or serrate at the apex only (P. Oedtri), or throughout
(P. Chrkei)-, those of ovate teeth are always dentate or incised, the segments not
infrequently being mucronate. These dentations may be erect, or deilexcd at the
tip only, or altogether, and sometimes the whole tooth is deflexed. These conditions give
L: