GLOSSARY 211 
Pinnate. A compound leaf with 
the leaflets attached along 
the sides of a central axis. 
Pinnatifid. Pinnately cleft at 
least half way to the midrib. 
Pistil. The floral organ in which 
the ovules are found (7). 
Pistillate. With pistils and with- 
out stamens (11). 
Placenta. Part of the ovary to 
os the ovules are attached 
(7). 
Pollen. Microspores of a seed 
plant. 
Polygamous. With perfect and 
staminate flowers. When the 
staminate are on the same 
plant as the perfect it is poly- 
gamo-monecious and if on 
separate plants it is poly- 
gamo-diccious (12). 
Polypetalous. Petals separate 
or if partly united separate 
at the base. 
Puberulent. Covered with mi- 
nute hairs. 
Pubescent. Hairy with short, 
soft, downy hairs. 
Pome. Fruit with several pa- 
pery or bony carpels_ sur- 
rounded by a fleshy hypan- 
thium as an apple or haw. 
Pyxis. Capsule in which the 
upper portion falls off as a 
lid or cap. 
Raceme. A flower cluster with 
a simple axis bearing stalked 
flowers. 
“a The axis of a spike- 
et. 
Ray. Marginal floret in com- 
posites with a strap shaped 
corolla. 
Receptacle. Surface to which 
the floral organs are attached 
or to which the florets are 
attached in a head of flowers. 
Regular. All organs in each 
whorl are about equal in size 
and form (17). 
Retrorse. Bent backwards or 
downwards. 
Rhizome. An underground stem. 
Rootstock (rootstalk). A rhi- 
zome. 
Rostellum. <A beak-like appen- 
dage on the stigma of the 
orchids. 
Sagittate. Shaped like an ar- 
row-head. 
Samara. A winged fruit as of 
the ash or elm; a key fruit. 
Scabrous. With a rough sur- 
face. 
Scape. A leafless peduncle aris- 
ing from an _ underground 
stem (27). 
Searious. Thin, dry, membran- 
ous and not green. 
Secund. Bearing flowers only 
on one side of an axis. 
Sepal. A member of the outer 
whorl of the perianth (9). 
Septicidal. Dehiscent along the 
dividing walls between the 
cells of a capsule (20). 
Serrate. With teeth like saw- 
teeth along the edge. 
Serrulate. Serrate with very 
small teeth. 
Sessile. Without a stalk. 
Setose. Bristly. 
Sheath. The basal part of the 
leaf which surrounds. the 
stem, in some monocotyledons, 
as the grasses. 
Silicle. A short silique. 
Silique. The narrow, two-valved 
capsule of the mustards. 
Sinus. The space between the 
basal lobes of a leaf. 
Spadix. A spike with a fleshy 
axis. 
Spathe. A large bract enclos- 
ing a flower-cluster. 
Spatulate. Narrow at the base 
with a broader rounded apex, 
spoon-shaped. 
Spicate. Borne in spikes. 
