THE DICTIONARY OF GARDENING, 
Pleospora—continued. 
of erect filaments, each bearing on, or near, the tip one 
or two conidia of a cylindrical or elliptical form, an 
entire or two-celled. This Fungus, known as Clado- 
sporium herbarum has long been regarded as an ill- 
developed condition of Pleospora herbarum ; but recently 
it has been denied that C. herbarum is a stage in the 
development of P. herbarum. Other forms of conidia 
also occur, intermingled with the Cladosporium, which 
are admitted to be conditions of P. herbarum. These 
FIG. 203. PLEOSPORA HERBARUM, MACROSPORE STAGE (known as 
Maerosporium sarcinula)—a, Conidium on Stalk (st); b, Coni- 
dium after falling from "Stat oa Another Form of Conidium, 
more typical of Sareinula Stage x 400, 
latter forms (see Fig. 203) resemble, in their general ap- 
pearance, the spores from the asci, e.g., in the forms 
Macrosporium sarcinula, Sporidesmium, and Alternaria 
Brassice. Of these forms of conidia, Macrosporium and 
Sporidesmium are oblong, with blunt ends, and are 
divided, as shown in Fig. 203, both lengthwise and 
crosswise, by partition walls, and each conidium is pro- 
duced on the end of a separate stalk. Alternaria has 
conidia produced on stalks, which may be sparingly 
branched; on the tip of each branch is a row of pear- 
— many-celled conidia, attached by the broader end, 
- and these separate very readily. The two forms Macro- 
ancl and Alternaria are regarded by Gibelli as 
se tic of the two species into which he divides 
= P. herbarum, as mentioned above. All the forms of 
conidia now described germinate readily, and, in suitable 
conditions of moisture and nourishment, produce myce- 
lium, which produces the Fungus anew. On the relation- 
ship of Cladosporium herbarum to the other forms 
greatly depends the view that must be taken of the 
disease-producing power of P. herbarum, and further 
investigations are required on this point. 
Remedies. Unfortunately, these are hardly procurable, 
because of the wide diffusion and abundance of the Fungi, 
and the internal = of the mycelium; but all 
- diseased parts should be burned. The best method to 
. prevent damage is to promote, in every way, healthy 
growth in the plants most liable to be attacked. 
PLEROMA (from pleroma, fulness; referring to the 
cells of the capsule). Syn. Lasiandra. Including Ohæ- 
togastra, Melastoma, Micranthella, and Rhevia (in part). 
Orp. Melastomacee. A genus containing about 124 
species of stove or greenhouse shrubs and sub-shrubs, 
~ rarely perennial herbs, sometimes climbing, often strigoso- 
pilose or hispid, natives of tropical South America, 
—* Brazilian. Flowers violet or purple, — 
disposed in terminal, trichotomously-branched panicles, 
large, sometimes with concave involucral bracts, very 
rarely four - parted; calyx tube ovoid, campanulate, 
ovate or- ‘oblong, | ae : 
— thrive either in tarty loam or peat, —— 
— shoots 
eer and cuttings of 
— 
Pleroma—continued. 
readily in a close frame at almost any time of year when 
they can be obtained. P. elegans forms a fine exhibition 
plant when well grown, and P. macranthum is one of the 
most beautiful subjects for covering a pillar or rafter in 
a greenhouse or cool stove. A season of rest should 
be allowed Pleromas in winter; but plenty of water 
may be applied through the summer. Except where 
otherwise stated, the under-mentioned species are shrubs, 
and require stove treatment. 
P. Benthamianum (Bentham’s).* fl. of a ‘beautiful dark 
purple, almost white in the centre, about Zin. across; panicles 
terminal, glanduloso-pilose. Autumn. J. oblong-lanceolate, 
rounded or somewhat cordate at the base, acute, nine-nerved, 
entire, the upper surface rough with small setee, the lower 
covered with —— silky hairs. h. 4ft. Organ Mountains, 
1841. (B. re 
P. elegans nt).* fl. rich blue, large, produced in abundance 
—— otras. t l. opposite, ovate- acuminate, bright shining 
green. Organ Mountains, 1844. (B. M. 4262.) 
P. —— a te iN s). jl, rosy-purple, in ter- 
minal 1. petiolate, ovate, acuminate, beset 
Hee sgn bristles a 
iandra petiolata (B. M. 3766), Pleionema Gaudichaudiana, 
Rhexia —— and R. petiolaris. 
P. um (Gay's veal A. white, in terminal panicles. Late 
autumn. l. ovate-ob png, Sore yes serrate, hairy. h. lft. to 2ft. 
Peru, 1874. Herb. (B. 
P. granulosum nulose). A reddish-purple, very showy, 
almost din, in — corolla concave, rotate ; petals obovate- 
oblong, acuminate, shortly apiculate panicles | terminal, with 
decussate branchlets. 1. coriaceous, decussately opposite, entire, 
attenuated at both ends, five-nerved ; petioles much shorter than 
the leaves. h. 10ft. Brazil. (B. R. 67 .) Syn, Lasiandra Fon- 
tanesiana (R. G. 1865, 466). 
P. heteromallum (one-woolly-sided). fl., petals purplish-violet 
five or six, obcordate; calyx pubescent, ‘with deciduous teet: th ; 
filaments short, conniving. July to Se tember, l oval- cordate, 
stalked, beset with flocky wool beneath. 4ft. to 6ft. Brazil, 
1819. SYN. Melastoma heteromalla (B. M. ; B. R. 664). 
P. holosericeum (silky). fl. pees: thyrse panicled, ter- 
minal, with the rachis very villous and compressed ; calyx 
tubular, July. i. sessile, ovate, five to seven-nerved, entire, 
densel with adpres on both surfaces. Branches te tetragonal, 
ith ad bristles. h. 6ft. 
cloth to 10ft. Brazil, 1816. 
A De podien axe a Lasiandra 
argentea, 
P. —— atin A synonym of P. — 
P. macranthum (large-flowered).* fl. rich d violet-p 
about 5in. in diameter, solitary, freely produ 
the branchlets. Winter. J. ovate or oblo: 
rugose. Branchesslender, terete. Brazil, 1 A very beautiful 
plant, fiowering the more profusely when in a large state, and 
orming one of the most effective subjects for greenhouse or 
conservatory decoration, It is best suited for trellises or walls, 
and, for this purpose, should be planted out, or prea in large 
tubs or boxes, after the first year’s growth. (B. M . 5721.) SYN. 
Lasiandra macrantha. 
P. m. floribundum (floriferous). fi. of a rich and brilliant 
violet-blue, produced almost throughout the year, and os 
nearly 14ft. in circumference. St. Catherine's, Brazil, 1870. 
most beautiful variety, producing its gigantic flowers on — 
plants when only about 3in. in height. It is better suited for 
pot culture than the type. 
P. sarmentosum a twiggy)” fl. dee violet or violet-purple, 
upwards of 2in. and disp in trichotomous 
panicles, 1, — or ovate-oblong, s short] stalked, Branches 
sarmentose. h. lft. to 2ft ayn at Pore, vag A beau- 
tiful, greenhouse, —— oige — B. M. 5629. 
P. 
semidecandrum —— * — v 
obtuse ; calyx tube campanulate, ri A — hispid, 
axillary, one- flowered, and termi aly. k —— — 
-ovate, acuminate, 
acute, five-nerved, ‘entire, setuloso- scabrous above, villous 
beneath. Branches te! and, as well as the petioles, 
villous, Brazil. Syn. P. Kunthianum (B. M. 4412). 
P. Villosum (villous). | fl. rosy-pink, terminal, few, pedunculate ; 
petals obovate, retuse, mucronate. May and June, l ovate, 
pene, entire, villous, Bice Melast meal 
: YN. Melasto 4 
2630; L. B. C. 853). re 
P. vimineum (t ). fl. purple; calyx covered with 
hairs, the segments te and mucronate. Jul; — 
- L ovate-lanceolate, acute, ond, 20 eee tang Son. we 
scabrous, but canescent h, — 1821. — 
Rhezia viminea (B. R. 
PLEURANDRA (of — 
Hibbertia (which m n 
16 E 
at the ante ol 
Included à undor o 
