40.
SOME TAXONOMIC TERMS DEFINED
- R.C.
Close.
ii very s h o r t time spent i d e n t i f y i n g New Zealand p l a n t s i s
s u f f i c i e n t to show the p r e v a l e n c e c f h y b r i d i s m i n our f l o r a .
The
l i t e r a t u r e on our f l o r a c o n t a i n s many terms which a p p l y to t h i s and
to o t h e r f e a t u r e s o f taxonomy.
Thus i t i s necessary that t h e i r
purpose and l i m i t a t i o n s s h o u l d t e w e l l u n d e r s t o o d ,
The f o l l o w i n g
terms a r e , t h e r e f o r e , p r e s e n t e d :
Specie s:
That stage i n the e v o l u t i o n a r y process where forms become
segregated i n t o two or more s e p a r a t e a r r a y s , p h y s i o l o g i c a l l y i n c a p a b l e
cf i n t e r - b r e e d i n g .
The main f a c t o r t h a t s e p a r a t e s s p e c i e s i s i s o l ation.
T h i s can be g e n e t i c a l , r e p r o d u c t i v e , e c o l o g i c a l or geographical .
Jordanon:
A t r u e b r e e d i n g group of s i m i l a r i n d i v i d u a l s , d i s t i n c t
from any o t h e r such 'group.
Simple s p e c i e s : * jordanon to which s p e c i f i c rank has been g i v e n
and which i s not c l o s e l y r e l a t e d to any o t h e r j o r d a n o n . e.g.
Agathis a u s t r a l i s .
Compound s p e c i e s : Two or more c l o s e l y r e l a t e d j o r d a n o n s , which
i t has been c o n v e n i e n t to u n i t e t o g e t h e r under the one name,
e.g. Rubus a u s t r a l i s .
Variety:
Any j o r d a n o n o f a compound s p e c i e s s u f f i c i e n t l y d i s t i n c t
from any o t h e r o f the jordanons so as to a l l o w i t to be e f f e c t i v e l y
d i a g n o s e d , e.g. M a c r o p i p e r excelsum v a r , pei tta,corum,
Linnean:
A compound s p e c i e s , f r e q u e n t l y i n a very wide sense, t o g e t h e r w i t h a l l the h y b r i d s between i t s jordanons and t h e i r epharmones, e.g. Cyathodes a c e r o s a , leptospermum
scoparium,
Olearia
a r b o r e s c e n s , Hebe s a l i c i f o l i a .
I t may i n c l u d e "more than one
species.
Epharmone:
An u n s t a b l e form of a j o r d a n o n which i s due te e n v i r o n mental i n f l u e n c e and d i f f e r s markedly from the s o - c a l l e d 'usual or
normal" form.
Cf course the normal form i s as much an epharmone
as any o t h e r , but i t i s g e n e r a l l y the most abundant, e.g. Senecic
l a u t u s has l o w l a n d , montane and a l p i n e epharmones.
!
I8fffl:
^n i n d e f i n i t e term, a p p l i e d f o r convenience to an i n d i v i d u a l
of unknown s t a t u s .
Ty_pe:
R e f e r s to the o r i g i n a l d e s c r i b e d m a t e r i a l , i . e . the f i r s t v a l i d
p u b l i c a t i o n c f the name and d e s c r i p t i o n ,
Cultigen:
For a form of unknown o r i g i n , found o n l y i n c u l t i v a t i o n ,
e.g. Nothopanax m a c i n t y r e i ,
Hybrid:
T h i s i n v o l v e s a c r o s s between p l a n t s c f d i f f e r e n t s t a t u s ,
e.g. we have i n t e r - j o r d a n i c , i n t e r - s p e c i f i c and i n t e r g e n e r i c h y b r i d s .
H y b r i d swarms:
I n d i c a t e s a l l the i n d i v i d u a l s which occur between two
s p e c i e s , e.g. there i s a range of forms between M e l i c o p e s i m p l e x and
M. t e r n a t a , some b e i n g n e a r e r to one s p e c i e s than the
other.
These
h y b r i d s , known as M. x t e r s i m p l s x are to be found i n the W a i t a k e r e s .
S i m i l a r l y the h y b r i d forms between C o r o k i a b u d d l e o i d e s and C. c o t o n e a s t e r , Coprosma propinqua and C. r o b u s t a are to be found at H u i a .
These h y b r i d forms are i n some cases so d i s t i n c t t h a t they have been
1*1.
•
••
.
*
d e s c r i b e d as s p e c i e s , e.g. i n t h e genus C o r o k i a , the h y b r i d i s desc r i b e d i n Cheeseman (19251 as C. cheesemanii ( C a r s e ) , w h i l e the
Coprosma h y b r i d has been d e s c r i b e d as C. cunninghamii (Hook.).
S i m i l a r l y the c r o s s between M y r t u s b u l l a t a and M. obcordata has been
known as M. r a l p h i i .
The h y b r i d forms between D a n t h o n i a p i l o s a and
D. s e m i a n n u l a r i s are known as P.. .x semi p i l o s a , and the many forms
between Hebe e l l i p t i c a and H. S a l i c i f o l i a are known as B. x e l l i p s a l a .
Polymorphy:
The d i f f e r e n t parts, of an i n d i v i d u a l p l a n t , e.g. l e a v e s ,
f l o w e r s , s t i p u l e s , may v a r y g r e a t l y .
S i m i l a r l y among groups of
c l o s e l y - r e l a t e d i n d i v i d u a l s , t h e r e may be d i f f e r e n c e s i n the form of
the v a r i o u s p l a n t s making up the group, i . e . a t a p a r t i c u l a r time.
Thus polymorphy i s the v a r i a t i o n w h i c h occurs w i t h i n i n d i v i d u a l
plants or w i t h i n species.
Examples o f I b i s are g i v e n by Cockayne and
a l i e n (1927).
Phenology.
The c o n d i t i o n where d i f f e r e n t s p e c i e s and even v a r i e t i e s
have d i f f e r e n t f l o w e r i n g p e r i o d .
The study o f t h i s i n r e l a t i o n to
the N w Zealand f l o r a has been r e l a t i v e l y n e g l e c t e d and much remains
to be c l a r i f i e d .
e
Homoblastic
species:
These a r e p l a n t s i n which the l e a f - f o r m and
h a b i t does net v a r y throughout the l i f e - h i s t o r y , e.g. Geniostoma
ligustrifolium.
H e t e r o b l a s t i c spp.
Those which possess a d i s t i n c t j u v e n i l e form w i t h
a change to the a d u l t , e.g. C a r m i c h a e l i a spp.
Seme s p e c i e s f r u i t
w h i l e s t i l l i n the j u v e n i l e form, e.g. P a r s o n s i a h e t e r o p h y l l a .
Others such as Blechnum f i l i f o r m e do not reproduce u n t i l the a d u l t
form i s a t t a i n e d .
The
f o l l o w i n g terms a r e of more r e c e n t i n t r o d u c t i o n :
Ecotypes:
A l l the members of s p e c i e s t h a t are f i t t e d to s u r v i v e
i n a p a r t i c u l a r environment w i t h i n the t o t a l range of the s p e c i e s .
Ecotypes c o n f i n e d to a p a r t i c u l a r h a b i t a t — t h e y are s t i l l i n t e r f e r t i l e but d i f f e r m o r p h o l o g i c a l l y .
Ecospecies:
0
A l l t h e ecotypes g e n e t i c a l l y so r e l a t e d t h a t they a r e
a b l e t o exchange genes f r e e l y w i t h o u t l o s s o f f e r t i l i t y o r v i g o u r
i n the o f f s p r i n g .
Coenospecies:
A l l t h e e c o s p e c i e s so r e l a t e d t h a t they may exchange
genes among themselves t o a l i m i t e d e x t e n t through h y b r i d i s a t i o n .
Comparium:
A l l the coenospecies between which h y b r i d i s a t i o n i s possi b l e e i t h e r d i r e c t l y o r through i n t e r m e d i a t e s , s t e r i l e h y b r i d s a r e
g e n e r a l l y produced.
No h y b r i d s can be produced between members o f d i f f e r e n t
comparia.
T h i s t e r m i n o l o g y i s o f r e c e n t o r i g i n and i f adopted would
change our genera t o c o e n o s p e c i e s .
A Comparium would be equal t o
a group o f genera:
Gnaphalium
Ewartia
Raoulia —
Helichrysum
Leucogenes
COMPARIUM
42.
DIVERGENT SPECIATION
Comparium - no c r o s s i n g at
Comparium
\
—
Coenospecies
Ecospecies
Ecotype
—
all.
-* Coenospecies - s t e r i l e h y b r i d s , no
gene exchange.
E c o s p e c i e s - P. h y b r i d s are o b t a i n e d
and a c e r t a i n amount of
gene exchange i s p o s s i b l e .
Ecotype - c r o s s i n g p o s s i b l e and the
a
p r o d u c t s are f e r t i l e .
The. taxonomy o f Ne w Zealand's n a t i v e p l a n t s i s g r e a t l y
I n c o n s i d e r i n g the v a s c u l a r p l a n t s a l o n e ,
c o m p l i c a t e d by h y b r i d i s m ,
we f i n d more than 300 groups of h y b r i d s , these o c c u r r i n g i n the f e r n s ,
c o n i f e r s , g r a s s e s , sedges, o r c h i d s , beeches and many other w e l l T h i s v a s t amount of h y b r i d i s m w i l l
known groups (Cockayne, 1929 a ) .
n a t u r a l l y upset our i d e n t i f i c a t i o n of a specimen, but a t the same
time i t p r o v i d e s many i n t e r e s t i n g problems which need c l a r i f i c a t i o n .
I n c e r t a i n genera h y b r i d i s m i s more r i f e than i n o t h e r s .
A l i s t of
these i s g i v e n below:
Asplenium
(numerous h y b r i d s , e s p e c i a l l y between A. b u l b i f e r u m and
others.
Hypolepis.
Podocarpus.
Uncinia.
P t e r o s t y l i s (many around Auckland)
Nothofagus.
Muehlenbeckia.
Clematis,
P i t t o s p o r u m , ('numerous h y b r i d s )
Rubus.
C o r i a r i a ( s p e c i e s , when they occur
Nothopanax.
t o g e t h e r , h y b r i d i s e abundantly,
Coprosma ( i d e n t i f i c a t i o n of l a r g e - as a t Mt. Egmont).
l e a v e d forms i n A u c k l a n d area i s A l s e u o s m i a ( v e r y d i f f i c u l t genus,
confused by h y b r i d i s m ) .
, the exact s t a t u s of many of i t s
Olearia.
s p e c i e s i s not e l u c i d a t e d ) .
An i n t e r e s t i n g example of a h y b r i d i s t h a t between
M e t r o s i d e r o s r o b u s t a and M. tomentosa.
T h i s i s to be found on
Rangitoto Is.
A thorough study of the l i f e - h i s t o r i e s o f p l a n t s i s of
importance to taxonomy, e.g. a marked d i s t i n c t i o n i n the j u v e n i l e
form s e p a r a t e s Sophora t e t r a p t e r a (no j u v e n i l e form) from S.
s p e c i e s of New Zealand p l a n t s show more o r l e s s s t r o n g l y marked
dimorphy or even polymorphy as they go from the j u v e n i l e t o the
a d u l t stage.
these changes may be abrupt or g r a d u a l .
Classical
examples o f h e t e r o b l a s t y occur i n P a r s o n s i a . C a r m i c h a e l i a , Pseudoand many
panax, P h y l l o c l a d u s , Podocarpus d a c r y d i o i d e s , S c h e f f l e r_a a:
other genera.
An i n t e r e s t i n g example o f jordanons and t h e i r r e l a t i o n to
h e t e r o b l a s t y i s p r o v i d e d by Leucopogon f a s c i c u l a t u s .
There are
p r o b a b l y i n t h i s s p e c i e s two j o r d a n o n s , one of which possesses a
j u v e n i l e stage.
Because of the l a c k of i n v e s t i g a t i o n n e i t h e r has
been e l e v a t e d to v a r i e t a l s t a t u s .
A s i m i l a r c o n d i t i o n probably
exists i n Schefflera.
A l s o i m p o r t a n t t o taxonomy i s the herbarium and the e x p e r i mental garden.
The l a t t e r i s g e n e r a l l y n e g l e c t e d but i t s e r v e s a
g r e a t purpose i n e l u c i d a t i n g many problems r e l a t i n g t o h y b r i d i s m .
C o l l e c t e d m a t e r i a ] may be grown so as t o f i n d the s u s p e c t e d p a r e n t s .
Epharmones, or suspected ones, can be p l a n t e d to see how they r e a c t
to changed c o n d i t i o n s .
The herbarium, on the o t h e r hand, must be
consulted frequently.
But o b v i o u s l y no c o l l e c t i o n of h e r b a r i u m
specimens, however complete, i s s a t i s f a c t o r y w i t h o u t the added i n f o r m a t i o n from f i e l d s t u d i e s and e x p e r i m e n t a l c u l t u r e s .
Thus the
43.
r e v i s i o n of a genus must be c a r r i e d out i n the f i e l d as w e l l as i n
the l a b o r a t o r y .
A good i n t r o d u c t i o n to taxonomy i n r e l a t i o n to the New
Zealand f l o r a i s to be found i n a paper by Cockayne and A l l a n ( 1 9 2 7 ) .
A l l the s c i e n t i f i c names used i n t h i s a r t i c l e a r e those. ...
i n Cheeseman ( 1 9 2 5 ) .
References.
1923. H y b r i d i s m i n the N.Z. F l o r a .
Cockayne, L.
New P h y t . , X X I I ( 3 ) , 105.
Pamph. 5 7 5 . 1 2 .
1927. The B e a r i n g of E c o l o g i c a l S t u d i e s on
and
B o t a n i c a l Taxonomic Conceptions and
A l l a n , H.H.
Procedure,
Journ.Ecol., XV(2), 234-77.
Cockayne', L.
1 9 2 9 a . H y b r i d i s m i n the F o r e s t s of New Zealand.
Acta F o r e s t a l i a Fennica, 34,
1-23.
Pamph. No. 5 7 5 . 1 2 .
1 9 2 9 b . D i e V e g e t a t i o n der E r d e , XIV.
Vegetation
of New Zealand.
Liepzig.
In English.
CELMISIA CORIACEA Hook.
- T.C.
Chambers.
D u r i n g a combined F i e l d Club-Botany Department e x c u r s i o n to
N a t i o n a l Park i n May, 1949, one p l a n t of C e l m i s i a c o r i a c e a was found
growing n e a r the Lower Tama Lake.
T h i s s p e c i e s has not p r e v i o u s l y
been r e c o r d e d from N a t i o n a l Park,
On Mt, Egmont G. W. Mason has a l s o
found two p l a n t s t o g e t h e r i n f l o w e r under T a h u r a n g i B l u f f ( 4 , 5 0 0 f t . ) ,
a l s o a new r e c o r d .
On the d i s t r i b u t i o n o f t h i s p l a n t Cheeseman s a y s — "North
I s l a n d : R e p o r t e d from the Tararua Mountains by Buchanan, but I have
seen no specimens from thence.
South I s l a n d : Abundant throughout
i n a number o f d i s t r i c t s , e s p e c i a l l y i n the c e n t r a l and w e s t e r n
p o r t i o n s o f the Southern, A l p s .
A l t i t u d i n a l range 1 , 5 0 0 — 4 , 5 0 0 f t . "
He c o n t i n u e s :
"A t r u l y n o b l e p l a n t , p r o b a b l y the f i n e s t s p e c i e s of
the
genus.
I n i t s most l u x u r i a n t s t a t e i t has a s h o r t s t o u t stem
which w i t h the o l d l e a f - s h e a t h i s sometimes as t h i c k as the w r i s t ,
and i s crowned w i t h numerous s p r e a d i n g and e r e c t l e a v e s from among
which a r i s e one or s e v e r a l s t o u t scapes (sometimes b r a n c h e d ) , b e a r i n g
heads sometimes more than 3 i n c h e s diameter w i t h l o n g narrow r a y s . "
I n F e b r u a r y and May of 1951 f u r t h e r v i s i t s were made to
the p l a n t a t Tama Lake and i t appears to be t h r i v i n g w i t h s e v e r a l
s m a l l v e g e t a t i v e o f f s h o o t s but t h e r e was no s i g n o f any f l o w e r .
Photographs were tahea and these s h o u l d be o f g r e a t i n t e r e s t f o r
f u t u r e comparisons.
I t i s p o s s i b l e t h a t there are o t h e r , as y e t
u n d i s c o v e r e d , p l a n t s of t h i s s p e c i e s a t N a t i o n a l P a r k , but i f so
they are c e r t a i n l y not common.
I f t h e r e are no o t h e r f r u i t i n g
p l a n t s i n the area i t i s c e r t a i n l y i n t e r e s t i n g how the seed t r a v e l l e d
such a l o n g d i s t a n c e and s e t t l e d i n such a s u i t a b l e a l p i n e environment.