498 PERENIDEBOLES 



Perenideboles Goyena. Acanthaceae (iv. B). i Nicaragua. 



Perennial, living for more than two years. 



Pereskia Plum, ex L. Cactaceae (i). 18 trop. Am., W.I. Leafy 

 plants (see fam.). Some, e.g. P. aculeata Mill. , climb like Rubus with 

 recurved thorns. 



Pereskiopsis Britton et Rose (Opnntia et Pereskia p.p.). Cactaceae (i). 

 12 trop. Am. 



Perezia Lag. Compositae (12). 75 Texas to Patagonia. 



Pereziopsis Coulter. Compositae (12). i Guatemala. 



Perfoliate (1.), united round the stem, Baptisia, Buplairum. 



Perforate, pierced through, or with translucent dots. 



Perfumes, Acacia, Acorns, Atidropogon, Citrus, Curcuma, Dipleryx, 

 Iris, Mesita, Michelia, Osmanthus, Pandanus, Phtmieria, Pogostemon, 

 Polyanthes, Rosa, Thymus, &c., &c. 



Pergamena Finet. Orchidaceae (II. 4). i Japan. 



Pergularia L. Asclepiadaceae (n. 3). 15 Afr. and trop. As. 



Peri- (Gr. pref.), around; -anth, see below; -carp, the fruit wall; 

 -chylous, with aqueous tissue round the green tissue; -derm, bark; 

 -gone, perianth; -gyny, cf. Ovary; -sperm, nutrient tissue round the 

 embryo, derived from the \-\\\c&\\\\<->,Aizoaceae, Canna, Caryophyllaceae, 

 Nymphaeaceae, Phytolaccaceae, Piperaceae. 



Periandra Mart, ex Benth. Leguminosae (in. 10). 6 Brazil. 



Perianth, the outer covering of the fl., composed of non-reproductive 1., 

 usu. divided into an outer greenish whorl, the K, and an inner, 

 coloured, the C. Concrescence is frequent, and the petals may be 

 aborted (only recognisable for certain when many closely related forms 

 possess them), thus giving an apctalous fl. Fl. with perianth, chlamy- 

 deous, without, naked or achlamydcous; with one whorl, haplo- or 

 mono-chlamydeous or ' incomplete' 1 (apetaloiis if the phenomenon is clue 

 to suppression of C), with two whorls, di- or diplo-chlamydeous or 

 'complete? P with 1. of one kind only (tepals] homo-chlamydeotis, of two 

 kinds (sepals forming a calyx, and petals a corolla), heterochlamydeous. 

 The P (K, C) may be hypo-, peri-, or epi-gynoits; of free organs 

 {poly-phyllous, -sepalons, -petalous) or concrescent (gamo-phylloits, 

 -sepalous, gamo- or sym-petalous] ; in the latter case the concrescent 

 part or tithe bears the free lobes, teeth, or segments together forming the 

 limb. It may also be regular (actinomorphic) or irregular (zygo- 

 morphic, or asymmetrical}. If it fall as the bud opens, it is caducous, 

 just after fert, deciduous; if it remain unwithered round the fr., per- 

 sistent; withered, marcescent; enlarged, as in Physalis, accrescent. 



A homochlam. P may be sepaloid (looking like a K in colour and 

 texture) or petaloid (like a C). The aestivation is described in the 

 terms given under Aestivation. 



The sepals are commonly leafy and green, but sometimes woody 

 (some Myrtaceae, &c.), or brightly coloured (Clerodendron, some 

 Ranunculaceae, &c.). In many epig. fls. they are much reduced, e.g. in 

 Umbelliferae and Rubiaceae. In Compositae they are frequently 

 repres. by a pappus of hair or bristles. If concrescent, the K is de- 

 scribed by the terms given for the C. In Malvaceae, some Rosaceae 

 (e.g. Potentilla) and Lythraceae there is an epicalyx of apparent stipular 

 nature (see also Dipsaceae). 



