THE PERIANTH 
77 
( zygom orphic , or asymmetrical ). If it fall as the bud opens, it is 
caducous, just after fertilisation, deciduous , if it remain unwithered 
round the fruit, persistent , withered, marcescent , enlarged, as in 
Physalis, accrescent. 
A homochlamydeous perianth may be sepaloid (looking like a calyx 
in colour and texture) or petaloid (like a corolla). 
The aestivation is described in the terms given above. 
The sepals are commonly leafy and green, but sometimes more or 
less woody (some Myrtaceae, &c.), or brightly coloured (Clerodendron, 
some Ranunculaceae, &c.). In many epigynous flowers they are much 
reduced, e.g. in Umbelliferae and Rubiaceae. In Compositae they are 
frequently represented by a pappus of hairs or bristles. If concrescent, 
the calyx is described by the terms given for the corolla, below. In 
Malvaceae, some Rosaceae {e.g. Potentilla) and Lythraceae there is an 
epicalyx of apparent stipular nature (see also Dipsaceae). 
The petals are usually of some other colour than green, and of 
delicate texture. They may be narrowed at the base, as in wallflower, 
into a claw (; unguiculate ), fringed with hair- like teeth, as in pinks 
( fimbriate ), bifid, tri-fid , &c. (cf. leaves) or divided into several long 
segments (laciniate) ; they may be spurred (with long hollow projection, 
as in Viola), saccate or gibbous (with projecting broad pouch), scaphoid 
(boat-shaped, as in Loasa), &c. The general form of the sympetalous 
corolla may be tubular , funnel-shaped ', urceolate (urn-shaped), ca?n- 
panulate (bell-shaped as in Canterbury bells), rotate (wheel-shaped 
with little or no tube, as in Veronica), salver-shaped (ditto, but with 
long tubular portion, as in primrose), spurred , saccate , gibbous , ventricose 
(swollen out all round in the basal part) ; if irregular, it may be labiate 
or bilabiate (with two projecting lips, as in Labiatae), personate (labiate, 
mouth closed by projecting lobe, as in Antirrhinum, &c.), helmet- shaped, 
ligulate (strap-shaped, as in dandelion, &c.), &c. 
The shape, texture, &c. of the individual sepals, petals, calyx-lobes, 
corolla- lobes, is described as if they were leaves. 
The Stamens or microsporophylls of a flower, taken 
together, are termed the androeceum. In flowering plants 
the microspores and microsporangi are termed pollen-grains 
and pollen-sacs , but otherwise differ little in essentials from 
those of Pteridophyta. 
The stamen (Fig. 6) is usually a stalked organ composed 
of a filament bearing an anther , the latter usually of two 
chief lobes or thecae united by a prolongation of the filament 
( connective ). Each lobe usually contains two pollen-sacs, 
which split along definite lines of dehiscence to allow the 
pollen to escape. 
Descriptive Terms. The androeceum or stamens may be hypo-, 
peri-, or epi-gynous ; epi-phyllous , -peialous, or -sepa 'lous (concrescent 
with perianth, corolla, or calyx) ; diplostemonous (in two whorls, the 
outer alternating with the corolla, and equally numerous with it), 
