TOW Roscoea

Robert Hamilton robhamilton@trump.net.au
Mon, 10 Feb 2003 02:59:57 PST
Hi  all,

Roscoea  is a  small genus  of late  spring / summer  growing   plants 
of the  ginger  family ,  Zingiberacea.  They  have  a  growing  point 
from which a  cluster  of thickened  roots decend ,  somewhat  like  a 
Dahlia  but   in minature  form.  The leaves are reminiscent of a 
minature  sweet corn, with  flower  at  the apex , which  to  my  eye 

is  somewhat  orchid like (thinking  Masdevallia)  with one  large 
decending  petal  and  several smaller petals  above  and  beside the 

main  petal. They  originate  mainly from India,  Nepal  and  China.

In  Tasmania they  need  partial  to  full  shade   and   additional 
summer  watering  to  grow  well.  They  tolerate  moisture  when 
dormant  and  do  equally  well in the ground or  pots. For  those  in 

cooler  climates  they  are  said  to  be outdoors hardy in Britian.
They  germinate  easily  from  seed . When sown in late summer
germination  usually occurs in autumn,  while  seed sown in early 
spring  emerges with the timing of  mature  plants. Some  species tend 

to  seed around  a  bit  including into  adjacent  pots. Mature  plants 

can  be  divided in  winter.

The biggest  problem with Roscoea is  identification  of the species.
Several  species  have  been perpetually misnamed  . The best  treatment

I  have  read of the  genus  is  by Richard  Wilford from  RBG Kew in
the March 1999 quarterly  bulletin of the Alpine  Garden  Society.

I  grow  the  following   but  cannot absolutely guarantee the  identity

of  my  species.They range  from 5cm (2 inches )  to  30cm (12 inches)

tall.

Roscoea  alpina  -  a  small  species with  mauve to  purple  flowers
which  is  easily  grown  and  seeds  freely.

Roscoea australis  -  small  purple /  mauve  flowers  similar  to
alpina  but  has broader  and  shorter  leaves.

Roscoea auriculata - this plant  has been distributed in  Australia as 

Roscoea purpurea or purpurea procera. It  grows  well  but does  not 
tolerate  too much  sun - I  often  find it  wilting  after a warm  day,

but it   recovers  with a  good water in the  evening. Flowers  are a 

deep violet-purple. The auriculata  refers  to the ear shaped first 
leaf on the pseudostem.

Roscoea cautleoides - in its  yellow   form it  is easily  recognised 

but  purple  and  white  forms  are  becoming available with the
explosion of  new plant  material  from  China.  I  find it needs  help 

to  set seed  and the  seeds are difficult  to recover from  amongst 
the bracts.

Roscoea humeana - this  has a  large  hooded dorsal petal  , larger 
than  the  labellum giving it a distinct appearance. It  is  commonly 

purple  , but  yellow  , cream  and  white  forms do  occur.  My 
seedlings  are  reasonably  new but  it  seems to  be  a vigorous =
grower.

Roscoea purpurea  - this  is  the  type  species  which  was  described

in  1806.  Flowers  are pale  purple  or  mauve. It  is  said  to  be
the most  vigorous  species  growing up  to  50cm  ( 20 inches )  tall.

I  have  kept  my  original  plant in a  pot  and  have  not  found it 

to  be this  vigorous, but it  has quite  broad  and  heavy  leaves.  I

intend  to plant  in the  garden  next  spring  as  I  now  have  my
own  seedlings . To illustrate the difficulties  with identification I

have now  almost  convinced myself  that my plant  is  R capitata - my 

plant  has  flowers of  rich deep  purple on a long peduncle- seen the

image.
A red form  of R purpurea  was  discovered in 1994 a unique  colour in

the  genus.

Roscoea scillifolia- this  is  the  smallest  of the  genus  growing 
little  more than a  few  cm tall. The  flowers can  be  pink  , purple

or  white. I  have a pink  form whose  flowers are  fairly  fleeting.
It  seeds  around   quite  freely  and  appears last of the  species I 

grow - in flower   at  present  in early February.

Roscoea tibetica - my  plants  are  still unflowered seedlings. It is 

another  small species  with  typically  dark purple  flowers , which 

can  also  range  from violet  to  mauve , rose or  white. The 
photograph in the  AGS  article  shows  horizontal  lateral  petals 
making it look  more like a  typical  orchid  flower.

The  following list  of  species  I  have  not grown is  taken  from
the  AGS article.

Roscoea Beesiana  - a  vigorous  hybrid  between auriculata and 
cautleoides with variable amounts  of violet striping.

Roscoea capitata -rich  deep purple

Roscoea forrestii- small  , yellow  or  purple  flowers.

Roscoea ganeshensis - a  recently  discovered  species  from Nepal.
Pale  purple  flowers , with  narrow  dorsal petal  is a   paler colour

than the rest of the  flower.

Roscoea praecox - a  new  species  collected on the Alpine Garden
Society China  Expedition. Purple   with  up to  six white  lines on the

base of the  labellum.

Roscoea schneideriana - dorsal is  pale pinkish -purple  with rest of
the  flower a  darker violet-purple.

Roscoea tumjensis - dark  purple  similar  to  humeana with  labellum
larger than the dorsal  petal.

Roscoea  wardii - purple   flowers.

I have posted  some Roscoea to  the wiki which  I  have  dragged out of 

my archives -  none  are  photographic masterpieces but  give  some
idea  of the species available.

http://pacificbulbsociety.org/pbswiki/index.php/…

Roscoea alpina -  sorry  I didnt  remove the  dead  flower.

Roscoea auriculata makes an  attractive  small clump.

Roscoea capitata - obtained as   seed  as R purpurea but my  =93homework=94=

makes  me think this  is  the correct name - in reality  it is a  rich 

deep purple.

Roscoea cautleoides- the  colour is  a little  washed out on this  image

Roscoea humeana -the split dorsal  petal  is  not a normal  feature but

the image illustrates its =93fuller =93 flower.

Roscoea ?Beesiana- this  is  Lyn=92s  image of  a plant  she obtained as =

R cautleoides which  we think  may be the  hybrid  R Beesiana, said  to 

have variable  violet  striping.

Rob  in Tasmania

Temperate Marine  Climate -equivalent USDA 8-9
Very occasional extremes -2 C ( 29 F)   to  39 C (101 F).
Average rainfall  27.7 inches - fairly evenly spread.


I have nothing important to add to Rob's introduction regarding culture

and
species, I don't grow quite as many types in my garden. Different little
plants that flower in the heat of summer in the shade are most
welcome,and
the flowers are delicate little beauties. I have found they do better in
pots for me than in the ground but that is probably because of
competition
from trees and shrubs for water during hot spells.They certainly are not
difficult to grow as long as they have enough water and protection from

the
sun.
	The conditions here in Canberra are probably harsher than in =
Rob's
Tasmanian garden, this is a long way north on the mainland and inland as
well ,where we have long hot dry summers with temperatures up in the =
high
30's C (90=92s F) and winters with many night time frosts down to -9 C =
(16
F)  at times and Roscoeas handle this without problems with little
protection. I wish they
grew as lushly here as they do in the U.K.,I remember particularly how
beautiful they were growing in the Lakes District Horticultural Society
garden at Holehird.

Lyn in Canberra



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Hi  all,

<underline><fontfamily><param>Doctor</param>

</fontfamily></underline><fontfamily><param>Doctor</param>Roscoea  is
a  small genus  of late  spring / summer  growing   plants  of the
ginger  family ,  Zingiberacea.  They  have  a  growing  point  from
which a  cluster  of thickened  roots decend ,  somewhat  like  a
Dahlia  but   in minature  form.  The leaves are reminiscent of a
minature  sweet corn, with  flower  at  the apex , which  to  my  eye
is  somewhat  orchid like (thinking  Masdevallia)  with one  large
decending  petal  and  several smaller petals  above  and  beside the
main  petal. They  originate  mainly from India,  Nepal  and  China.


In  Tasmania they  need  partial  to  full  shade   and   additional
summer  watering  to  grow  well.  They  tolerate  moisture  when
dormant  and  do  equally  well in the ground or  pots. For  those  in

cooler  climates  they  are  said  to  be outdoors hardy in Britian.
They  germinate  easily  from  seed . When sown in late summer
germination  usually occurs in autumn,  while  seed sown in early
spring  emerges with the timing of  mature  plants. Some  species tend

to  seed around  a  bit  including into  adjacent  pots. Mature
plants  can  be  divided in  winter.


The biggest  problem with Roscoea is  identification  of the species.
Several  species  have  been perpetually misnamed  . The best
treatment I  have  read of the  genus  is  by Richard  Wilford from
RBG Kew in the March 1999 quarterly  bulletin of the Alpine  Garden
Society.


I  grow  the  following   but  cannot absolutely guarantee the
identity of  my  species.They range  from 5cm (2 inches )  to  30cm
(12 inches) tall.


Roscoea  alpina  -  a  small  species with  mauve to  purple  flowers
which  is  easily  grown  and  seeds  freely.


Roscoea australis  -  small  purple /  mauve  flowers  similar  to
alpina  but  has broader  and  shorter  leaves.


Roscoea auriculata - this plant  has been distributed in  Australia as

Roscoea purpurea or purpurea procera. It  grows  well  but does  not
tolerate  too much  sun - I  often  find it  wilting  after a warm
day, but it   recovers  with a  good water in the  evening. Flowers
are a  deep violet-purple. The auriculata  refers  to the ear shaped
first  leaf on the pseudostem.


Roscoea cautleoides - in its  yellow   form it  is easily  recognised
but  purple  and  white  forms  are  becoming available with the
explosion of  new plant  material  from  China.  I  find it needs
help  to  set seed  and the  seeds are difficult  to recover from
amongst  the bracts.


Roscoea humeana - this  has a  large  hooded dorsal petal  , larger
than  the  labellum giving it a distinct appearance. It  is  commonly
purple  , but  yellow  , cream  and  white  forms do  occur.  My
seedlings  are  reasonably  new but  it  seems to  be  a vigorous
grower.


Roscoea purpurea  - this  is  the  type  species  which  was
described in  1806.  Flowers  are pale  purple  or  mauve. It  is
said  to  be the most  vigorous  species  growing up  to  50cm  ( 20
inches )  tall. I  have  kept  my  original  plant in a  pot  and
have  not  found it  to  be this  vigorous, but it  has quite  broad
and  heavy  leaves.  I intend  to plant  in the  garden  next  spring
as  I  now  have  my own  seedlings . To illustrate the difficulties
with identification I have now  almost  convinced myself  that my
plant  is  R capitata - my  plant  has  flowers of  rich deep  purple
on a long peduncle- seen the image.

A red form  of R purpurea  was  discovered in 1994 a unique  colour in
the  genus.



Roscoea scillifolia- this  is  the  smallest  of the  genus  growing
little  more than a  few  cm tall. The  flowers can  be  pink  ,
purple or  white. I  have a pink  form whose  flowers are  fairly
fleeting. It  seeds  around   quite  freely  and  appears last of the
species I  grow - in flower   at  present  in early February.


Roscoea tibetica - my  plants  are  still unflowered seedlings. It is
another  small species  with  typically  dark purple  flowers , which
can  also  range  from violet  to  mauve , rose or  white. The
photograph in the  AGS  article  shows  horizontal  lateral  petals
making it look  more like a  typical  orchid  flower.


The  following list  of  species  I  have  not grown is  taken  from
the  AGS article.


Roscoea Beesiana  - a  vigorous  hybrid  between auriculata and
cautleoides with variable amounts  of violet striping.


Roscoea capitata -rich  deep purple


Roscoea forrestii- small  , yellow  or  purple  flowers.


Roscoea ganeshensis - a  recently  discovered  species  from Nepal.
Pale  purple  flowers , with  narrow  dorsal petal  is a   paler
colour than the rest of the  flower.


Roscoea praecox - a  new  species  collected on the Alpine Garden
Society China  Expedition. Purple   with  up to  six white  lines on
the base of the  labellum.


Roscoea schneideriana - dorsal is  pale pinkish -purple  with rest of
the  flower a  darker violet-purple.


Roscoea tumjensis - dark  purple  similar  to  humeana with  labellum
larger than the dorsal  petal.


Roscoea  wardii - purple   flowers.


I have posted  some Roscoea to  the wiki which  I  have  dragged out
of  my archives -  none  are  photographic masterpieces but  give
some idea  of the species available.


http://pacificbulbsociety.org/pbswiki/index.php/…


Roscoea alpina -  sorry  I didnt  remove the  dead  flower.


Roscoea auriculata makes an  attractive  small clump.


Roscoea capitata - obtained as   seed  as R purpurea but my
=93homework=94 makes  me think this  is  the correct name - in reality  =
it
is a  rich  deep purple.


Roscoea cautleoides- the  colour is  a little  washed out on this
image


Roscoea humeana -the split dorsal  petal  is  not a normal  feature
but the image illustrates its =93fuller =93 flower.


Roscoea ?Beesiana- this  is  Lyn=92s  image of  a plant  she obtained as

R cautleoides which  we think  may be the  hybrid  R Beesiana, said
to  have variable  violet  striping.


Rob  in Tasmania


Temperate Marine  Climate -equivalent USDA 8-9

Very occasional extremes -2 C ( 29 F)   to  39 C (101 F).

Average rainfall  27.7 inches - fairly evenly spread.



I have nothing important to add to Rob's introduction regarding
culture and

species, I don't grow quite as many types in my garden. Different
little

plants that flower in the heat of summer in the shade are most
welcome,and

the flowers are delicate little beauties. I have found they do better
in

pots for me than in the ground but that is probably because of
competition

from trees and shrubs for water during hot spells.They certainly are
not

difficult to grow as long as they have enough water and protection
from the

sun.

	The conditions here in Canberra are probably harsher than in =
Rob's

Tasmanian garden, this is a long way north on the mainland and inland
as

well ,where we have long hot dry summers with temperatures up in the
high

30's C (90=92s F) and winters with many night time frosts down to -9 C
(16 F)  at times and Roscoeas handle this without problems with little
protection. I wish they

grew as lushly here as they do in the U.K.,I remember particularly how

beautiful they were growing in the Lakes District Horticultural Society

garden at Holehird.


Lyn in Canberra



</fontfamily>=

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