Re: new case/how to heat

Barry Meyers-Rice (
Fri, 28 Jan 94 18:02:51 MST

In part because of a few of my recent _Ping_ questions, Kevin Snively
of this group made a heroic effort (doubly heroic since he's sick right
now) and typed in two articles from the International Pinguicula
Study Group Newsletter. I took these two articles, and cleaned them up
only slightly, and am posting them here.

This file is being distributed without permission from the IPSG, although
as Kevin noted there are no copywrite notices on the Newsletter. Since
the information in these articles has gone through two hands (Kevin's and
mine) since publication, there may be transcription errors. For the original,
consult the IPSG Newsletter.

Incidentally, I just got my first copy of the Newsletter (No. 3) and am
exceedingly impressed. In this 20 page pamphlet are (apparently)
authoritative articles on tissue culture, _P._ X l'hautil, a nomenclatural
synopsis of the genus (70 species---Jan, have you seen this?), field
notes on _P.vulgaris_, a discussion of _P.colimensis_ vs. _P. hemiepiphytica_,
a book review, and a new species described. Also, a few inserts included
a cladistic tree of all the Pings, colour photocopies of plants in the
wild and cultivation, plus weather data for more than 50 localities in
Mexico! What a great Newsletter!

One clever trick I've never heard before is described by a hybridizer. He
claims that if you want to cross species A and B, where B will be the seed
parent, mix B pollen (which you've killed with UV radiation) with A pollen.
Apparently, this dead B pollen makes the plant more receptive to the A pollen.
Huh. But I'm a little concerned that this guy claims to have produced
crosses between _D.capensis_ and _D.binata_, and also between _D. burkeana_
and _D. capensis_, which have since died in seedling stage. Call me a

To subscribe, write

Ron Mudd
10, High Street
Nr. Rushden
NN10 9LS

US Cash or pound sterling accepted, send single payment for several issues.

Read and enjoy!



Taken from The International Pinguicula Study Group
Newsletter No. 1 April 1992

_Pinguicula longifolia_ Ram.
An introduction to its cultivation based on
personal experience in Hampshire, England.

by Kevin Hughes _Introduction_

The long leaved butterwort occurs in three distinct ranges in S.
W. Europe, each of which contains an isolated subspecies.

_P. longifolia ssp. longifolia_ inhabits the central Pyrenees,
_P. longifolia ssp. caussensis_ the mountains of south central France, and
_P. longifolia ssp. reichenbachiana_ the Maritime Alps and Appenines.

Typical habitats are in deep limestone gorges where colonies
clad the cliffs on the tufa deposits left by reliable seepages or falls of
water. Most colonies are out of direct sunshine and healthy plants can
even be found growing in deep shade, underneath overhangs, where the
plants cling to the walls, ceiling and stalactites. _P. longifolia ssp.
caussensis_ is the smallest subspecies producing, on average shorter
leaves and smaller flowers ( corolla : _P. caussensis_ 22--35 mm., _P.
longifolia_ 30--46 mm.) The leaves of _P. caussensis_ are also broader
relative to length, giving it a superficial resemblance to cliff dwelling
plants of _P. leptoceras. The flowers of all the subspecies exhibit a
variation of color from purple to light blue and typically have white


This presents very few problems. This species, with the
exceptions of _P. grandiflora_ and _P. lusitanica_ has proved has proven
the most adaptable, of the European species, to the maritime climate of
South West England.

Growth in a mild winter (the last four here) can commence as early
as mid-February and this can be a problem. Once growth begins even a
mild frost can kill, although the species, when dormant, can withstand
temperatures of at least -12 C. Therefore it can not be treated as hardy
and needs the protection of a glass house. In mine the nighttime air
temperature is allowed to fall to -1 C while the plants are dormant, but no
lower than 0 C once growth commences.

The largest hibernacula break dormancy first and the plant may
then remain active for the next ten months. These larger plants are also
the first to bloom; starting in late March and producing up to four
flowers per plant. Flowering has finished here by late April.

If regularly exposed to temperatures in excess of 18 C the plants
respond with early dormancy and this means no flowers next year! Thus it
is important to find a cool location in the garden for the summer months,
a north aspect being the obvious solution. Alternatively, artificial means
of cooling the plants could be sought, although I find this not necessary.
should plants go into early dormancy they require treatment which is no
different from those remaining in growth i.e. you _do not_ need to put
them in the fridge.

My experience suggests that this species resents being stood in
trays of still water. Instead the potted plants are better stood on damp
peat or sand contained within a propagator to maintain high air humidity.
This high humidity is vital if healthy leaf growth is desired. If
conditions are right the compost will soon be carpeted with moss. This
seems to benefit the growing plants but, if left unchecked, weakens them
in the long term. Any Liverworts or Fern Prothalli should be removed as
they appear. If very vigorous, the mosses will need removing during the
growing season, and the pot will need top dressing with fresh compost.

With the commencement of growth I start a once monthly-foliar feed
with an Orchid fertilizer diluted to 3/4 strength. Other than this the
plants take nutrients from their compost and the numerous small
invertebrates they capture.

Plants are repotted every two years and the top 2 cm. of compost
replaced on an annual basis. This species does not keel over and die if
transplanted whilst in growth, although I wait until the Autumn dormancy
before repotting. The wild habitat suggests a preference for alkaline
soils but a compost of neutral or slightly acidic reaction suits them just
as well in cultivation. I have now switched from Sphagnum, and Sedge peat
to "Coco-peat"as the basis of my potting medium and have experienced no
reduction in success. The main problem with the "Coco-peat" is its
tendency to succour mildew on the surface when kept wet; this is less of a
problem under the cultivation techniques outlined above. For preference i
use the compost of 3:2:1:1 of "Coco-peat", Perlite, loam/J. I. No. 1 and
coarse sand. To each litre of mix I add 1 Tablespoon of crushed Dolomite

Seed is best sown fresh for good germination. No modification of
the compost is necessary but moss needs to be kept in check as the minute
seedlings struggle to compete with it.

_P. longifolia_ makes very few gemmae, none on most smaller
specimens, so it is slow to bulk up vegetatively. I find that the gemmae
are best separated during the Autumn repot and then treated as normal.

Aphids are the main pest, although slugs and snails can wreak
havoc. Aphids are easily removed with a fine paint brush and are most
damaging when infesting the hibernacula. If not removed quickly, deformed
growth may be the result the following spring.

The above is a general description of my methods for growing this
species and should be treated as a rough guide only - every garden (and
gardener) is unique!

Flora Europaea
Caspers Monograph
Flowers of S. W. Europe,
a field guide, Polunin
& Smythies


The International Pinguicula Study Group
Newsletter No. 1. April 1992

_Pinguicula agnata_?
by Ron Mudd

_P. agnata_ was originally described by Casper in 1963. He described
the plant from material collected by Moore and Wood in 1948, from the state
of Hidalgo in Mexico. The original plants, it is said, were found on the lower
portion of nearly sheer calcareous north facing cliffs, on dry rocky slopes,
at an estimated altitude of 5000'.

A summary of Casper's original description states that _P. agnata_
is perennial and consists of a rosette of between 8--12 spatulate to
obovate-oblong pale green leaves, each leaf being 35--55 mm. long and
10--15 mm. wide and without an upturned margin. The 1--3 flower stalks
are 50--120 mm. long, hairy, and each carry 1 large flower, 18--22 mm.
long (including spur). The Isoloba type flower is white to pale blue. The
corolla tube is 8--10 mm. long, 3--5 mm. wide and without a palate. The
spur is 3--4 mm. long and formes an obtuse angle with the corolla tube.
There is no mention of a winter rosette.

In his work on carnivorous plants (1986), Slack describes _P. agnata_
as having strap shaped leaves with rounded ends, which are unusually thick
and succulent, and forming rosettes to 13 cm. in diameter. The flowers are
described as medium sized, wide throated of mauve-blue to pale violet in
color with two deep flecks at the base of each. The throat is described as
greenish. It is mentioned that no winter rosette is formed.

The aim of this piece is two-fold;

a) To describe the different plants which are at present being grown as
_P. agnata_, and to mention two obviously allied plants.

b) To describe my observations of variation which can be induced in one of
these types by growing in different cultivation materials.

_a)_The Different_Plants._

At present it is apparent that in Europe two plants which are
obviously different are being commonly grown as _P. agnata_. The first,
(which I shall call "Blue", and to which the work in section b) applies),
fits the descriptions of Casper and Slack very well, apart from the fact
that it readily forms an obvious "winter" rosette. The second is a
smaller plant (5--6 cm. max. diameter in summer rosette), which is very
similar in both rosette forms which I shall call "Pale". The flowers of
this plant are similar in shape and size to "Blue" but are very much paler
in color, indeed the blue areas often appear pale brown/cream. The throat
usually appears pale lemon as opposed to the originally described green,
however the two flecks mentioned by Slack are apparent but very pale. The
summer rosette is very much more ground hugging than in the "Blue" plant
where the leaves often point upwards from the surface at many angles. The
leaves are much shorter and much more rounded in "Pale", slightly darker
in coloring, but are equally as succulent. This plant is akin to the
plant shown by Kondo (Carnivorous plants of the world, 1983) as _P. agnata_,
and from my own experiences is the one more commonly grown as this plant
on the Continent, where as the "Blue" plant is the more commonly grown in
Great Britain, (possibly due to Slack's involvement).

The "Blue" plant is often cultivated as _P. lilacina_, a mistake
which is reinforced by the photograph of it in Kondo. The original
description of _P. lilacina_ by Schlechtendal and Chamisso (1830), shows
it very different to this plant, (corolla tube with palate), and Casper
stresses the obvious close relationship between _P. lilacina_ and the
southern U.S.A. species, a comment that cannot be applied to these plants.
I believe these "Blue" plants are _P.agnata_ as they conform to the original

The "Pale" plants are sufficiently different in size, leaf shape,
growth patterns and other smaller areas, to be, in my opinion, considered
as different species. This, however, rests with the taxonomists and may
be resolved one day. This plant is now being imported to Britain, from
Holland in large numbers and is being sold in garden centers as _P. agnata_.

The differences described above are from my observations of plants
grown in identical material (2:3 Perlite:Vermiculite) in identical growing
conditions. The size of the leaf and rosette, flower color, time of dormancy
and length of flowering period can all be affected by the growing medium
as I will endeavour to show later.

Although not widely in cultivation at the moment, two other plants
which appear to be related to _P. agnata_, and could be confused with
this species in leaf and rosette form are P. "Sierra de Tamaulipas" and P.
"Ayautla". In the first the leaves are again succulent, strap shaped and
pale green. However, once this plant flowers it can no longer be confused
with _P. agnata_ . The structural differences between the two flowers can
quite clearly be seen, and when the fact that P. "Sirra de Tamaulipas" is
white to pale pink is known, the difference is confirmed.

The second plant, P. "Ayautla", again possesses pale green succulent
leaves, but when the fact that these leaves are hairy on both sides (!) is
known any confusion is dismissed.

Although these two plants have not been officially described as
species to date, I believe that this is to be done in the near future.


During 1989 (after many losses of the more delicate pings due to
rotting in the previous years), I decided to investigate the use of different
growing media in an attempt to overcome this problem. From a growing
knowledge of pings, I suspected that a very open, free draining medium, with
large pockets of saturated air, would most closely represent the natural
growing medium. However as I did not understand which other factors would
influence growth and the rot problem, I decided to investigate a wide range
of composts. These are listed below;

1. 100% _Sphagnum_ Moss Peat,
2. 50:50 Peat:Sand,
3. 100% Sand,
4. Rockwool/Foam (Wellbanks Orchid Medium),
5. Sponge ( bathroom type),
6. 3:2 Vermiculite:Perlite,
7. 50:50 Peat:Perlite,
8. Brand Potting Compost,

The plants used were all from leaf cuttings for the same parent
plant. The rootless winter rosettes were laid upon the surface of the
composts in January. In February roots were seen to be emerging from the
rosettes, and watering (from below) was commenced. All of the pots
containing the plants were kept in the same part of the green house and
kept at a min temp. of 10 C. Growth commenced well and the first flowers
appeared in March. When all were flowering it became apparent that some
were considerably paler than others, and as this became more apparent, the
more flowers that opened, it was obvious that something was affecting
flower color. As everything else was constant, and enough plants had been
growing in each medium to rule out mutation, I concluded that it must be
the growing medium. This was reinforced as three distinct groups were

1. Palest - composts 1,2,7,8,
2. Pale - composts 3,4,
3. Vivid - composts 5,6,

As the year progressed it also became apparent that similar groups
could be formed with respect to the size achieved by the plants, the more
open composts producing the larger plants.

At the end of the growing season, when watering had been ceased for
4 weeks, i.e. at the end of October, the plants were removed from the growing
media. It was apparent at this stage that the roots of the plants in composts
1,2,3,4,7 & 8 had been continually rotting during the growing season, and
that although they had been replaced, to varying degrees, were in no way as
healthy as the roots of the plants from No. 5 & 6 media. The roots of the
plants grown in the Perlite:Vermiculite mix had even retained their very
fine root hairs which are apparent on the last 5--6 mm. of the mature roots.

Although none of the plants had rotted those in medium 6 were
evidently the most healthy plants and so this system has since been adopted
with the result that no plants have sence been lost, even in the most
delicate "Pings".


Although the above can only be a brief summary of my trials, my
observations of these plants throughout the year convinced me that the
appearance of _P. agnata_ can be influenced to such an extent by the growing
medium that the same plant must appear quite differently in different
collections. However although depth of color and size of rosette may be
affected, the shape of the flower and leaf is not, and as I now grow "Blue"
and "Pale" in the same medium, this does not account for the differences
between these plants.