36 ENGLISH 
816 polymorphic — of more than one form, variable [f767, g777, s897]. 
817 polyoicous — see heteroicous [f768, g778, s898]. 
818 polyploid — with the chromosome number n, greater than 2x but an exact multiple of x; 
e.g,, a plant, tissue or cell with more than 2 complete sets of chromosomes [f769, g779, 
]. 
819 polysety — more than one sporophyte produced from a single gametoecium, each from a 
separate archegonium and thus each with its own calyptra (cf. polyembryony) [f770, g780, 3 
$900 | 
]. 
820 polytrichoid — having the habit or characters of Polytrichum (see: -oid); e.g., with large 
rigid leaves or a somewhat bristly or hairy calyptra [f771, g781, s901]. 
822 pore — a small aperture, the opening in the wall of some cells; e.g., in leaf hyalocysts and 
hyalodermis of Sphagnum. Also typical of hyalocysts in the lamina of the Leucobryaceae, 
Leucophanaceae and Theriotia, and the cancellinae of Encalyptaceae, Leucophanaceae 
and Calymy (see pseudopores, air pores, pit) [f775, g782, s903]. 
823 porose — having pores [f781, g783, s909]. 
824 posterior — in transversely inserted leaves, the side or surface oriented toward the axis; 
ventral or adaxial (opposed to anterior) [f546, g470, s911]. 
825 postical — the ventral surface of a stem; that leaf margin oriented towards the base of a 
longitudinal or obliquely inserted leaf (see proximal; opposed to antical) [f782, g469, 
s912]. 
Q^, 1 T . 
I t y — see int lary branching [(544, g-apx, s670]. 
827 potamocolous — growing in rivers [f1100, g784, s914]. 
828 pottioid — having lingulate leaves with a strong costa, isodiametric papillose cells above, 
and typically a sheathing base with cancellinae; as in Tortula, Encalypta and 
Calymperaceae; (see: -oid) [£783, g785, s915]. 
829 precocious — developing early; e.g., spores with intracapsular germination; (cf. 
endosporic) [f785, g1081, s916]. 
830 preperistome — see prostome [f786, g786, 1079, s917]. 
831 primary leaf — the initial leaf (underleaf) on a juvenile plant; generally differs 
morphologically from the later produced leaves (underleaves) [f408, g787, s630]. 
832 primary peristomial layer —- the middle layer of the peristomial cylinder that contributes 
in the formation of arthrodontous peristomes (see inner and outer peristomial layers 
[f243, g788, s169]. 
primary stem — main stem; in some mosses a long creeping, rhizome-like stem with 
leaves and rhizoids from which secondary stems arise; e.g., Pterobryaceae 
cnrnaott 
... (see frondose) (8992, g789, 1076]. 
gus stes dia) beginning; an organ in its earliest stage of 
2x erentiation; e.g., leaf primordium [f787, g790, s918]. 
proboscis "ud e: proboscises) — specialized leaf or leaf extension consisting 
ge ir may bear gemmae; in Calymperaceae and Streptopogon [f789, gn 
1 di il ; 
process e» "e ovid. of the diplolepidous endostome (also called segments), 
Es , i 1 outer peristome teeth [f573, g343, s920]. 
a si eres prostrate [f790, g704, s921]. 
prolate — longer than wide (opposed to oblate) [f1101, g-apx, s922]. 
