rare in S. England and S.AV. Scotland.—B. M. ; Appuldurcombe, Isle of
AA’ir iit; St. Leonai'd's Forest, Sussex; Ilsliam Valley, Torquay, and
AVembury, S. Devon. Near Creetown, Kirkcudbrightsbire.
A’ar. S. su b p ap illo sa Cromb. Journ. Bot. 1882, p. 273.—Thallus
greyisl'i-white, pruiiioso, almost entirely subgrariulato-unequal or
subpapillato-graiiulate. Apotheoia nearly moderate, pruinose, with
tu rgid margin.
A very singular and, if constant, well-marked variety, wliich is so abnormal
th a t at first sight it would scarcely be referred to this species.
I ll the single specimen seen the thallus lias only one or two short laoiuiæ
here and there visible at the extreme circumference. There are but two
apothecia present, iu which the margin is also slightly subpapillate.
Ilab. Cu the trunk of an old tree in a lowland tract—Dísír. Seen
only from E. England.—B. M. ; Bury St. Edmunds, Suftblk.
Subsp. 1. P . v e n u s ta Nyl. e.v Lamy, Bull. Soc. Bot. t. xxv, (1878)
p. 383.—Thallus cervine or oerviiie-grcyish, epruiiioso, somewhat
narrowly incised. Apotheoia moderate, tho margin crowned with
horizontal thalline lacinioli.— Cromb. Grevillea, xv. p. 78.— Physcia
jnilverulenta var. venusta Cromb. Lioh. Brit. p. 39 ; Loight. Lich.
Fl. p. 147 pro p a rte , ed. 3, p. 136 pro parte. Parmelia venusta
Acb. Meth. (1803) p. 211, t. 8. f. 5.
Diflers in the colour of the naked thallus, the narrower lacimæ, and the
coronate margins of the apothecia, which entitle it to rank as a subspecies.
I t is to be noted, however, that states occasionally occur evidently
belonging to this subspecies in which the receptacular margin is nearly or
almost denudate (form ecoronata Cromb.). The apothecia in the British
specimens are not numerous, though somewhat crowded.
Hab. Cn trunks of old trees in wooded upland situations.—Histr. Local
and scarce in S.AV. England, S.AV. Scotlaud, the S. and AV. Highlands,
and in S.AV. Ireland.—B. M. : llsham, Torquay, S. Devon. New Galloway,
Kirkcudbrightshire; by Loch Tay, Kenmore, Perthshire ; S. of Fort
AA’illiain, Inverness-shire. Carrigaloe, co. Cork; Ballynegarde, co.
Limerick.
Subsp. 2. P. p ity r e a Nyl. ex Lamy, Bull. Soc. Bot. t. xxv. (1878)
p. 383.—Thallus subeffuse, th inner, appressed and adnate, greyish-
whito or suboervine ; laoiniæ somewhat short, sorediate a t th e m a rgins
( K / , C aC l/) . Apotheoia small, pruinose, th e m argin crenulate
or sorediato-lacerate ; spores 0 ,0 2 4 -2 8 mm. long, 0 '0 1 5 - I8 mm.
thick.— Cromb. Grevillea, xv. p- 78 .— Physcia pulverulenta var.
p ity r e a Cromb. Lioh. Brit. p. 38 ; Leight. Lich. Fl. p. 146, ed. 3,
p. 135. Parmelia p ity rea Sm. Eng. Fl. v. p. 201. Lichen p ity reus
Ach. Brodr. (1798) p. 124 ; Eug. I3ot. t. 2064. Borrera p u lve ru lenta
y . grisea (Lam.) Mudd, Man. p. 111. Lichenoides glaucum
orhiculiire, segmentis latiuseulis, scutellis nigris Dill. Muse. 177, t. 23.
f. 71 0.—B rit. E.VS. : Aludd, n. 83 ; Leight. n. 370 ; Cromb. n. 51 ;
Larb. Lioh. Hb. n. 48.
AVell characterized by the thinner, more adnate thallus, the shorter and
marginally sorediate laciniæ, and the smaller apothecia with their usually
sorediate thalline margin. These characters, more especially the soredia,
which are sometimes very abundant and obliterate the lacimæ in the
centre of the thallus, make it a distinct subspecies. In our specimens
the apothecia, which are central, are not often present ; and the spermogones,
which are similar to those of the type, are also but rarely seen.
Hab Cn the trunks of trees, rarely on old walls, in maritime, lowland,
and upland cultivated tracts.—Di'sir. General and common in most parts
of Euo-land ; apparently rare in Scotlaud and the Chaunel Islands ; not
yet yTitli certainty gathered in Irelaud.—B. M. : Island of Guernsey.
Sahani Wood, Norfolk; near Bury, Suffolk; High Beech, Epping
Forest, Essex ; Basingstoke, Kent ; Glynde, Sussex ; Lymington, Hants ;
Hyde and Appuldurcombe, Isle of Wight ; near Cheltenham and Cirencester,
Gloucestershire; Edgeware, Aliddlesex; near Elstree, Herts ;
Pampisford, Canihridgeshire; near Adderbury, Cxfordshire ; Malvern
- and near Kempsey, Worcestershire; Harboro’ AJagna, Warwickshire;
Ludlow Park, Shropshire; Aberdovey, N. Wales; Carlton, Clevelaiid,
Yorkshire; Windermere, Westmoreland. Appm, Argyleshire; Blair-
driimmond, near Stirling ; Glen Ample, Perthshire ; Drum, near Aberdeen.
Subsp. 3. P. m u sc ig en a Nyl. Syn. i. (1860) p. 418.—Thallus depressed
a t tbe oiroumferenoe, more or less ascending in the centre,
livid-chestnut or oervine-browii, usually oæsio-pruinose; laoiniæ
somewhat short, dilated and discrete ( K / , C aC l/). Apotheoia with
th e th allin e margin crenate ; spores 0 ,0 2 4 -3 0 mm. long, 0 ,0 1 1 -1 5
mm thiok —Cromb. Grovillea, xv. p. 78.— Physcia pulverulenta var.
muscigena Leight. Lioh. F l. Suppl. p. 479, ed. 3, p. 136. Parmelia
muscigena Aoh. Lioh. Univ. (1810) p. 472.
Distino-uished by the laciniæ, the crenate margin of the apothecia, the
smaller spores, and the nature of the habitat. These differences, however
are scarcely sufficient to warrant our regarding it, with some older and
more recent authors, as a distinct species, hut only as a well-marked subspecies
of tbis very variable plant. In the only Britisli specimen gathered
the apothecia, which are elsewhere very rare, are not present, nor are the
spermogones visible.
Hah. Du decayed mosses on the ground in a subalpine region.--Disfr.
Found only on the summit of oue of the Central Grampians, Scotland,—
B. AI. ; Craig Tulloch, Blair Athole, Perthshire.
11. P. su h d e te rs a Nyl. Flora, 1878, p. 344.—Thallus orbicular,
moderate, pale-cervine, subnaked or here and th ere yellowish-sorc-
d ia te ; laoiuiæ somewhat short (K —) ; medulla yellow (K-j-deeper
yellow). Apotheoia unknown.
AVell distinguished from P. pulverulenta var. detersa Nyl. (which has
not occurred with us) hv the colour of the medulla. I t approaches
P. enteroxantlia Nyl., a IÑreiiean plant, hut differs m uot being wliite-
pruinose and in the medullary reaction. I t is never seen fertile.
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