BOTANICAL TERMS, 
205 
the petiole on each side. There are many 
kinds of pinnated leaves ; thus there is equally- 
pinnate (jmri-pinnatus), when the petiole is 
terminated abruptly, that is, without an odd 
leaflet; pinnate with an odd one (impari- 
pinnatus), when an odd leaflet or tendril ter- 
minates the petiole ; alternately pinnate (al~ 
ternatum-pinnatus), when the leaflets alter- 
nate; interruptedly pinnate (interrupt e-pin- 
natus), when the leaflets are alternately large 
and small ; decreasingly pinnate (decrescente- 
pinnatus), when the leaflets become smaller 
towards the apex ; decursively pinnate (de- 
cur sive-pinnatus), when the petiole is winged 
by the base of the leaflets, &c. 
JPinnatifid (pinnatifidus); a divided feather- 
veined leaf, in which the lateral segments are 
divided almost down to the axis (in pinnate 
leaves each division forms a separate piece). 
There are several varieties of this form. 
Pitcher ; a curious modification of the pe- 
tiole of some plants, capable of holding water, 
as in nepenthes and sarracenia. 
Pseudo-eostatum; falsely-ribbed, when the 
veins of the leaf become confluent in a line 
with the margin, as in myrtaceous plants. 
Pulvinus ; a swelling or protuberance at 
the base of the petiole on its lower surface, 
where it joins the stem. 
Radical; applied to leaves when they spring 
direct from the root. 
Radiating ; applied to the ribs when several 
radiate from the base of a netted leaf to its 
circumference, as in most of the lobed leaves. 
Ramastra ; same as stalklets or petiohdes. 
Rectinervium ; same as rectivenimn. 
Rectiveniutn ; straight-veined, when the 
veins proceed from near the base of the mid- 
rib, and lie nearly parallel with it. The leaves 
of glasses, orchideous plants, palms, &c, are 
of this nature. 
Refiexed ; applied when the veins of the 
leaf spread at an angle beyond 120 degrees. 
Reliquce; the withered remains of inarticu- 
lated leaves, which decay on the stem. 
Reniform (reniformis) ; kidney-shaped, that 
is, crescent-shaped, with the ends rounded, as 
in Asarum europmim, and various other plants. 
Retrqflexa ; reflexed, bent backward. 
Reticulated (reticidatus) ; netted-veined, 
that is, when the veins of the leaf cross in va- 
rious directions, forming meshes like network. 
Reticulum ; the fibrous sheath at the base 
of the leaves of palms. 
Rhomboid (rhomboideus) ; oval, a little an- 
gular in the middle, approaching to diamond- 
shaped, as in the leaves of Cltenop odium olidum. 
Rhombeus ; a rhomboid, applied to the out- 
line of leaves. 
Ribbed (costatum) ; where three or more 
prominent ribs proceed from the base to the 
apex of the leaf, as in the plaintain. 
Right-angled; applied whentheveins spread 
at an angle between 80 and 90 degrees. 
Rotund (rotundus) ; roundish, orbicular, a 
little inclined to oblong, as in Lysimachia num- 
mular ia. 
Rotu?idate(rotundatus, subrotundus) ; round- 
ish, same as rotund. 
Roundish (rotundus) ; orbicular, inclined to 
oblong. 
Runcinate (runcinatus) ; hooked back; 
curved in a direction from the apex towards 
the base, as seen in the leaf of the dandelion. 
Sagittate (sagittatus) ; shaped like the head 
of an arrow, that is, gradually enlarged at the 
base, into two acute straight lobes, as in the 
leaf of Rumex acetosella. 
Scabrities ; a peculiar warty kind of rough- 
ness on the surface of the leaf. 
Segments; the lobes of a leaf when divided 
to the midrib. 
Sessile (sessilus) ; where a leaf is attached 
to the stem without a petiole or stalk, stalk- 
less, as in Zygophyllum sessilifolium. 
Sheathing (vaginalis) ; when the petiole 
embraces the branch ; this chiefly occurs in 
grasses. 
Simple; when the blade of a leaf is not 
articulated or jointed with the petiole, but 
forms with it a continuous body. The term 
does not apply to the manner in which a leaf is 
cut or divided. 
Spatidate (spatidatus) ; oblong, with the 
lower end much attenuated, as in the leaf of 
the common daisy. 
Spreading ; applied to the veins of the leaf 
when they spread at an angle of between 40 
and 50 degrees. 
Stipes ; the petiole, or stalk of a frond. 
Stipels ; stipules situated at the base of the 
leaflets of some pinnated leaves. 
Stipules; membranous, leathery, or spiny 
appendages of the stem, situated at the base of 
the petioles in many plants ; they may be seen 
in the young shoots of willow trees. 
Straight-veined (rectivenium) ; when the 
veins of the leaf are parallel, and arise from 
near the base of the midrib, as in grasses. 
Struma; a swelling or protuberance, oc- 
curring in some leaves where the petiole and 
blade unite. 
Subidate (subulatus) ; awl-shaped, linear, 
narrow, tapering to a very fine point from 
a broadish base, as seen in the common 
furze. 
Tendril; a peculiar elongation of the 
petiole, enabling plants to lay hold of and 
support themselves upon objects which sur- 
round them. 
Tergeminate (tergeminatus) ; a form of 
leaf, where each of two secondary petioles 
bears a pair of leaflets, and the common petiole 
bears a third pair of leaflets. 
