m a te o f th e n um b e r o f species knoAAii to b o ta n is ts is a g re a tly ex ag g e ra te d o n e * , a n d th e p rev a len t
id e as re g a rd in g tb c ir d is trib u tio n n o le ss c o n tra c te d .
M a n y m o re p la n ts a re com m o n to m o s t co u n trie s th a n is su p p o sed ; I h av e fo u n d 6 0 N ew Z e a la
n d flowering p la n ts a n d 9 F e rn s to b e E iu ’o p ean ones, beside s in h a b itin g v a rio u s in te rm e d ia te
co u n trie s ; a n d am o n g st th e low er O rd e rs we fin d a g re a tly in c re a sed p ro p o rtio n o f species com mo n
to a ll c o u n t r ie s : th u s o f M o sses alone 50 a re fo u n d in N ew Z e a lan d an d Em ’o p e f ; o f Hepaticce 1 3 ;
o f Algse 45 a re also n a tiv e s o f E u ro p e a n s e a s ; o f F u n g i n e a rly 6 0 ; an d o f L ich en s 100.
So lo n g ago as 1 8 1 4 M r. B r o w n | d rew a t te n t io n to th e im p o rta n c e o f s u ch co n s id e ra tio n s , an d
g ave a lis t o f 1 5 0 E u ro p e a n p la n ts com m o n to A u s tra lia . T h e id e n tity o f m a n y o f th e se b a s r e p
e a ted ly b e e n ca lled in q u e s tio n , b u t a lm o s t in v a iia b ly e rro n eo u s ly , ad d ed to w liicb m o re m o d e rn
co lle c to rs h av e g re a tly in c re a s ed th e list.
T h e to o p re v a le n t id e a th a t th e p la n ts o f n ew ly discovered, iso la ted , o r li ttl e v is ited lo c alities
m u s t n e c e ss a rily b e new, b a s b e e n a fe rtile soiu’ce o f th e u n d u e m u ltip lic a tio n o f species. T h e re are
very m a n y cases o f n a tu i’a lists b a r in g b e e n so im p re ssed w ith th is id e a, th a t th e y h av e n o t th o u g h t i t
w o rth w h ile to co n su lt e ith e r b o o k s o r h e rb a ria b e fo re d e sc rib in g th e p la n ts from su ch sp o ts. T h e
N ew Z e a lan d F lo r a p re s en ts several in s ta n c e s o f t h i s ; tw o co n sp icu o u s o nes occm’ in th e g en u s
Oxalis', one, O. corniculata, is am o n g st th e m o s t widely diffused a n d v a riab le p la n ts in th e w o r ld ; o f
its v a rie tie s n o less th a n seven o r e ig h t species h av e b e e n mad e , m o s t o f th em supposed to b e p e c u lia r
to N ew Z e a la n d ; n o t o n ly is 0 . corniculata h en c e ex c lu d ed fr’om th e flora, b u t in th e d e sc rip tio n s o f
th e s e its v a rie tie s, n o allu sio n is m a d e to t h a t p la n t§ . I n th e case o f th e o th e r species th e e r ro r is
m o re excusable, a n d m a y b e s till o p en to q u e s tio n !!; i t is th a t o f O. Ma g ella n ica , o rig in a lly discove red
in F u eg ia , a n d im p e rfe c tly d escribed b y F o rs te r, whose v e ry in d iffe ren t specimens o f i t a re in th e
* According to the loose estimate of compilers, 100,000 is the commonly received number of known plants :
from a multiplicity of data I can come to no other conclusion but that half that number is much nearer the truth.
This may well be conceived, when it is notorious that nineteen species have been made of the common Potato, and
many move of Solanum nigrum alone. Pleris aquilina has given rise to numerous book species, Vernonia cinerea of
India to fifteen at least. Many of the commonest European plants have several names in Europe, others in India,
and still others in America, besides a host of garden names for themselves, their hybrids and varieties, all of Avhich
are catalogued as species in tlie ordinary works of reference whence such estimates are compiled.
t In fact the distribution of some Cryptogams is so wide, that I have visited a spot in a high southern latitude,
nearly all whose plants are not only identical with those of Great Britain, but inhabit many intermediate temperate
and tropical countries. Cockburn Island, in lat. 64° 12' S. and long. 64° 49' W., nearly fulfils this condition
; I thereon collected nineteen plants, of wliich tluee-fourtlis arc natives of England.
X Appendix to Flinders’s Voyage, vol. ii. p. 592.
§ I have stated very confidently in the body of this work that eight of Cunningham’s and Richard’s species of
this genus are all referable to one. This view will probably not meet the approbation of the local botanists, who will
point to the constancy with which some of the states retain their characters under varied conditions. I value such
facts very highly, and attach great weight to them, and did these varieties occur only in New Zealand I should
perhaps have withheld so strong an opinion on the subject; but such is not the case. 0. corniculata varies as much
in numerous other parts of the world; and admitting, as every one must, that varieties are known to retain their
characters with more or less constancy for certain periods, some other evidence is necessary to shake the opinion of
the botanist who grounds his views on an examination of the plant from all quarters of the globe.
II As no identification is proved till all the organs of the plants to be compared liave been studied, there is yet
a possibility of these three species proving distinct, but I do not at all expect i t ; the only dillcrciice I can find is
a greater obliquity and emargination of the petals of the New Zealand species, but that character varies so much
both in this plant and in others of the genus that it loses all specific value.
B ritis h M u se um . AVhen rc -fo u n d in N ew Z e a la n d i t was d e s c rib ed as n ew , a n d c a lled 0 . cataractoi,
a n d w h en fo u n d a th i r d tim e in T a sm a n ia , was ca lled b y s till a th i r d n am e , 0 . lac tea. I n th is case
a m o re im p o rta n t fa c t was sm o th e re d th a n th a t o f tlie d is trib u tio n o f 0 , co rn ic u la ta , n am e ly , th a t o f
a v e ry p e c u lia r p la n t o f th e s o u th tem p e ra te zone b e in g com m o n to th e s e th r e e w id ely su n d e red
lo c alities.
M a n y s im ila r in s ta n c e s m ig h t b e ad d ed , fo r th e r e a re sev e ra l N ew Z e a lan d p la n ts (as P te r is
aquilina) th a t h av e a d iffe ren t n am e in a lm o s t ev e ry c o u n try in th e Avorld, an d , p a r t ly from
ch an g e s in n om e n c la tu re , p a r tly from th e r e d u c tio n o f species, I h a v e fo u n d m y s e lf o b lig ed to q u o te
1 5 0 0 n am e s fo r th e 7 2 0 N ew Z e a lan d flow crin g -iflan ts de sc rib ed , a n d I b elieve I m ig h t h av e d o u b led
th e n um b e r h a d ray lim its n o t o b lig ed m e to re d u c e th e s y n o n ym y as m u c h as p o ssib le ; in m a n y
cases to o m u ch , I fear, fo r th e re q u irem e n ts o f w o rk in g b o ta n is ts in E u ro p e .
M -
The d istrib u tio n o f species h a s been effe c ted by n a tu r a l causes, b u t these are n o t n ec essa rily the
saíne as those to w h ich th e y are now exposed.
O f all th e b ra n c h e s o f B o ta n y th e r e is n o n e w h o se e lu c id a tio n d em a n d s so m u c h p re p a ra to ry s tu d y ,
o r so extensive a n a c q u a in ta n c e w ith p la n ts a n d th e ir affinities, as th a t o f th e ir g e o g rap h ic a l d is tr ib u tio
n . N o th in g is ea sier th a n to ex p lain aw’ay a ll obsciu’e p h e n om e n a o f d isp e rs io n b y scv^eral sp e c u la
tio n s o n th e o rig in o f species, so p la u sib le th a t th e su p e rfic ia l n a tu r a lis t m a y a c c ep t a n y o f th em ;
a n d to te s t th e ir so u n d n e s s d em an d s a com p reh en s iv e k n ow led g e o f fa c ts , w h ic h m o re o v e r r u n g r e a t
ris k o f d is to rtio n in th e h a n d s o f th o s e who do n o t k n ow th e v a lu e o f th e evidence th e y afford. I
h av e en d e av o u red to e n um e ra te th e p rin c ip a l fa c ts th a t ap p e a r to m ilita te a g a in s t th e p ro b a b ility o f
th e same species h a r in g o rig in a te d in m o re p la ces (or cen tre s) th a n o n e ; b u t in so d o in g I h av e o n ly
p a rtia lly m e t th e s tro n g e s t a rg um e n t o f a ll in fav o u r o f a p lu ra lity o f c e n tre s , viz. th e d ifficu lty o f
otherAvise a c co u n tin g fo r th e p re s en c e in tw^o Avidely su n d e re d lo c a litie s o f r a r e lo c a l species, whose
seeds c a n n o t h av e b e e n tr a n s p o r te d from o n e to th e o th e r b y n a tu r a l cau se s n ow in o p e ra tio n . T o ta k e
an in s ta n c e : how does i t h a p p e n th a t E d w a r d s ia g ra n d iflo ra in h a b its b o th N ew Z e a la n d a n d S o u th
A m e ric a ? o r Oxalis Ma g ella n ica b o th th e s e lo c a litie s a n d T a sm a n ia ? T h e id e a o f tr a n s p o r ta tio n b y
a e ria l o r oce anic cm’re n ts c a n n o t b e e n te rta in e d , as th e seeds o f n e i th e r co u ld s ta n d e x p o su re to th e
s a lt w a te r, a n d th e y a re to o heaAy to b e b o rn e in th e air. W e re th e s e th e o n ly p la n ts com m o n to
th e s e Avidcly-sundered lo c a litie s, th e p o s sib ility o f some e x c ep tio n a l m o d e o f tr a n s p o r t m ig h t b e a d m
itte d b y th o s e d is in c lin e d to rece iv e th e d o c trin e o f d o u b le c e n tr e s ; b u t th e e lu c id a tio n o f th e N ew
Z e a lan d F lo r a h a s b ro u g h t u p m a n y s im ila r in s ta n c e s eq u a lly difficult to a c co u n t fo r, a n d h a s developed
in n um e ra b le c o lla te ra l p h en om en a o f eq u a l im p o rta n c e , th o u g h n o t o f so CAÚdent ap p re c ia tio n .
T h e se , A\4iich all h e a r u p o n th e same p o in t, m a y be a rra n g e d as folloAvs :—
1. Seventy-scA^cn p la n ts a re com m o n to th e th r e e g r e a t so u th tem p e ra te m a sses o f la n d , T a s m
an ia , N cav Ze a lan d , a n d S o u th A m e ric a .
2. Comp a rativ ely few o f th e s e a re u n iv e rs a lly d is trib u te d species, th e g r e a te r p a r t b e in g p e c u lia r
to th e so u th tem p e ra te zone.
3. T h e re are upAvards o f 100 g en e ra , su b g cn e ra , o r o th e r w e ll-m a rk ed g ro u p s o f p la n ts e n tire ly
o r n e a rly co nfined to N cav Ze a lan d , A u s tra lia , a n d e x tra -tro p ic a l S o u th A m e ric a . T h e se a re re p r e s
en ted b y o n e o r m o re species in tAVo o r m o re o f th e s e c o u n trie s , a n d th e y th u s effect a b o ta n ic a l re la tio
n sh ip o r affinity b e twe en th em all, wh ich ev e ry b o ta n is t ap p rec iates.
d 2