102 
PA RIE TARIA 
Genus i. Parietaria 
Parietaria [Tournefort Inst. 509, t. 289 (1719)] L. Sp. PI. 1052 (1753) et Gen. PI. ed. 5, 471 (1754); 
Engler in Engler und Prantl Pflanzenfam. iii, pt. i, 115 (1894). 
Undershrubs or herbs. Leaves alternate, petiolate, simple, exstipulate. Inflorescences consisting 
of dense axillary cymes. Flowers wind-pollinated, polygamous, the terminal one pistillate and 
the lowest ones staminate, and the intermediate ones (the great majority) monoclinous. Perianths 
mostly tubular, with 3 — 5, usually 4, segments. Stamens 3 — 5, usually 4. Stigmas falling before 
the anthers of the same flower have dehisced. Endosperm sparse or copious. Cotyledons ovate. 
About 10 species ; temperate and tropical zones. Only British species : — P. officinalis (see below). 
I. PARIETARIA OFFICINALIS. Pellitory of the Wall. Plate no 
Parietaria Gerard Herb. 261 (1597); Ray Syn. ed. 3, 158 (1724); P. vulgaris Parkinson Theatr. Bot. 436 
(1640) including P. minor , p. 437. 
Parietaria officinalis L. Sp. PI. 1052 (1753)!; Hudson FI. Angl. 376 (1762); P.judaica Miller Gard. 
Diet. ed. 8, no. 2 (1768) non L. ; P. ramiflora Moench Meth. PI. 327 (1794); Rouy FI. France xii, 276 (1910); 
P. diffusa Mertens und Koch Deutschl. FI. i, 827 (1823); Syme Eng. Bot. viii, 126 (1868); P. officinalis var. diffusa 
Weddel in Arch. Mus. Hist. Nat. Paris ix, 507 (1857); P. officinalis race ramiflora Ascherson und Graebner 
Syn. iv, 623 (1911). 
leones : — Curtis FI. Bond, iv, t. 63 ; Smith Eng. Bot. t. 879; FI. Dan. t. 521 ; Reichenbach Icon, xii, t. 651, 
fig. 1318, as P. diffusa. 
Camb. Brit. FI. ii. Plate no. (a) Flowering shoot of P. officinalis var. ramosa. (b) Pistillate flower 
(enlarged), (c) Ripening ovary, with perianth partly dissected (enlarged), (d) Persistent perianths enclosing 
ripening ovaries, (e) Flowering shoot of P. officinalis var. simplex, (a — d) from Somerset (E. W. H.). (e) from 
Huntingdonshire (E. W. H.). 
Exsiccata : — Billot, 644. 
Perennial. Stem erect, ascending, or decumbent, more or less branched. Petioles short. Laminae 
oval or elliptical, cuneate at the base, subentire or entire, acute to subacute. Bracts with 2 chief 
divisions each of which is segmented, green with translucent glandular hairs. Flowers polygamous. 
Perianth purplish, glandular-hairy ; of the central monoclinous flowers with the tube as long as or 
longer than the segments ; of the lateral imperfect flowers with the segments longer than the tube. 
Stamens very sensitive. 
(a) P. officinalis var. genuina Syme Eng. Bot. viii, 126 (1868). 
Stems ascending or decumbent, with longer branches than in var. simplex. Laminae broader 
and shorter, more rugose especially when young. 
This is the common form of the species in England. 
(b) P. officinalis var. simplex comb. nov. ; P. diffusa var. simplex Bach in Flora xxiv, 735 (1841); P. 
diffusa var. fallax Grenier et Godron FI. France iii, no (1855); P. ramiflora var. fallax Giirke Plant. Eur. ii, 
80 (1897); Rouy FI. France xii, 276 (1910). 
Stems erect, much less branched. Laminae narrower, longer, and less rugose than in var. genuina. 
Local ; Somerset, Suffolk, Huntingdonshire, and doubtless elsewhere. 
France, Germany, Spain. 
The allied species P. erecta (Mertens und Koch Deutschl. FI. i, 825 (1823)) is a larger plant, erect, with larger 
and broader leaves, and with a shorter tube to the monoclinous flowers : it is not known as a British plant. 
Old walls, rocks, and hedge banks, preferring calcareous soil. Recorded for every county in 
England and Wales ; but rare in non-calcareous districts where it occurs rooted in the mortar 
of old walls : rare also in eastern England where the rainfall and atmospheric humidity are low. 
Local and rather rare in southern Scotland: not indigenous in the Highlands of Scotland. In 
Ireland, absent from or rare in many of the central and drier counties, rare in the west, frequent 
in the south, east, and north. 
France, Iberian peninsula, Italy (up to 1000 m.), Balkan peninsula, southern Russia; Asia Minor 
(up to 2000m.) to Turkestan; northern Africa; Madeira; Canary Isles. 
