3 6 8 F LO EA ANTAECTICA. [Fnegia, the
Afimis C. extensm. Good., quæ perigyniis costato-neiwosis, glaucis, squamis masmdis muticis, foliis, Iracteisque
patentibus vel recuiwis, sæpe involutis, differt. Bootf.
1 2 . Carex trífida, Cav., vid, Fl. Antarct. P t. 1. p. 8 9 .
H a e . Cape Tres Montes, C. Darwin, Esq.; Palldand Islands, abmidant, D ’Vrville, Capt. Sulivan
J . D. H.
A very noble species, abimdant in tlie Falkland Islands, growing with, and emulating in size, young Tussock
grass. Mr. Dar-win alone has gathered it on the American continent, and he only at Cape Tres Montes. Its
confined range is very singular, for it can scarcely have heen overlooked in Fnegia or the Strait of Magalhaens, had
it eidsted there ; and it is also probably the only plant common to New Zealand and the Falkland Islands, not found
abundantly in Tien-a del Fuego.
Carex trífida affords a remai-kable instance of apparent caprice in its choice of habitat ; for though common
iu the Falklands, along with the Bactylis ctespUosa (Tussock grass), and though there these grow iu company,
and under precisely the same conditions, yet the Tussock grass in America only appears in the southern extreme
of Fuegia, where it is unaccompanied by Carex trífida; whilst the latter is confined to a latitude eight hundred
miles north of Cape Horn. There is nothing whatever in the climate or soU of any part of western South Chili,
or Fuegia, that can he pronounced unfavourable to the growth of this Carex, whose absence there naturaUy
leads to the question, how is its presence in Cape Tres Montes and the Falkland Islands to be accounted for ?
did it originate in each of these two isolated localities ? was the seed transported over the intervening land, by
an agent whose operations were limited to the eastern, and western extremes only of Antarctic America? or,
have the individuals that once tenanted the intervening land, been destroyed? Any one of these hypotheses is at
first sight plausible, and the first, perhaps, the most so. New Zealand being a third, and fai- more remote, habitat
for this same species, which may thus be supposed to have had three sepai-ate origins. Such a question should
not be discussed ivith reference to a single species, but as one which concerns aE organized nature, whose phenomena
are amenable to general laws. Hypotheses, adopted to account for e.xceptional cases, if not viewed in
reference to the general rule from which these exceptions deviate, are generally fallacious ; and however much so.
they stm are apt to be magnified into laws. If we knew only such plants as are sporadic (the term given to species
which inhabit unconnected and remote localities) we might, perhaps, be justified in assuming it as an axiom, that
individuals of a species have sprung, at isolated localities, from as many similar parents ; the cases which appear to
demand this solution are, however, exceptions in Botanical Geography.
The study of the distribution of any one species or genus, or of the Flora of any one country, does not afford
scope enough for investigating satisfactorily such a subject as the origin ot the individuals of plants. If species,
genera, and small natui-al orders were sporadic, recurring wherever chmate and soil presented similar conditions,
several points of origin for the same species might be assumed. But it is not so : species, genera, and orders are distributed
within geogi-aphical limits, according to their extent ; the great mass of individual plants in the one case, and
of forms in the other, appear to have sprung from single centres, in the former case from a common parent, and to
have radiated from one point to greater or less distances around it, in proportion to the facilities for migration and
absence of checks to diffusion. The explanation of exceptions to this prevailing rule must then be sought in some
natural cause, capable of cotmteracting the general law, and not what, if adopted for the case of one species,
must he conceded ivith respect to all, and consequently force us to conclude that two classes of agents are required’
to effect one object, namely, the dispersion of \
7. U NC IN IA , Pers.
1. U ncinia tenuis, Poepp., Synops. P la n t. Am. Anstr. vol. iii. n. 2 4 0 . Kunze, Synops. der Beidgr.
t. 2 1 . Kunth, En. Pla n t, v o l.ii. p. 5 2 5 .
Falklands, etc?\ FLO RA ANTARCT ICA. 3 6 9
I I ab. Strait of Magalhaens; P o rt Famine, Chi?/.-A««/; Hermite Is la n d ; Cape H o r n ,/ . D. AT.
A species entirely confined to South Chüi, between Concepcion and Cape Horn.
The four species enumerated in this work, together with JJ. eñnacea, Pers. (a native of Valdivia and Chih) and
two new ones *, diagnoses of which Dr. Boott has kindly given, include all the extra-tropical American Uncinia
known to me.
2. U n c in ia phleoides, Persoon, Synops. vol. ii. p. 5 3 4 . Brongn. in Buperrey, Voy. Bot. p. 1 5 8 {excl.
syn. U . Maclovianee). Hook, et Arn. in Bot. Voy. Beechey, p. 5 0 . Carex plileoides, Cav. Icon. vol. v. p. 4 0 .
t. 4 6 4 . f. 1.
H a b . Chonos Archipelago; C. Barwin, Esq.
On several occasions I have alluded to the change which occurs in the vegetation of the western coast of South
America, at, or about, the latitude of the Chonos Archipelago. This arises from many species extending to (but
not crossing) that limit, both from much lower and higher latitudes, pf which the present plant affords an example.
U. pUeoides inhabits the plain of Quito, under the equator, at an elevation of 8,000 feet; it grows also at
1. U n cinia niultifaria, Nees ; spica crassa densiflora basi attenuata apice conico mascula nuda, stigmatibus 3,
perigyniis (arista divaricata vix duplo brevioribus) linearibus ore truncato striato-nervosis scabris margine ciliatis
squama oblonga obtusa paUida apice albo-membranacea ciholata angustioribus longioribusque. Boott.
Hab. Chiloe, Cuming (n. 44. Hci-h. Hooker.)
Culmus subbipcdalis, triqueter, firmus, lævis, inferne foliatus. Folia 3—4 lin. lata, culmo longiora vel æquantia,
glaucescentia, margine versus apicem facieque scabra, supremum angustum. Spica 2-1-poU. longa, superne 6 lin.
vel aristis divaricatis mensurata 10 hn. lata, basi attenuata, (1 lin. lata), nuda ; apice conico, (4 hn. longo),
mascula, Squamæ oblongæ, obtusæ, paUidæ, demum fuscæ, apice ciliolalæ, albo-membranaceæ, infra apicem
fermgineo-zonatæ, nervo dorsah vis prominente; masculæ breviores. Ferigynium 3-|—f lin. longum, -g- hn. latum,
biconvexum, superne præcipue scabrum, margine ciliatum, püis sursum longioribus demum fasciculatis, ore ti-un-
cato cüiolato, arista 2 lin. extra os exserta, 5 lin. longa, divaricata, imo basi torta. Achænium 2 lin. longum. -f lin.
latum, triquetrum, utrinque sm-sum convexum, fuscum, impresso-punetiüatum, apice et basi attenuatum. Stylus
basi subincrassatus. Stigmata 3, non plumosa. Boott.
Ab U. erinacea, Pers., perigj'nüs lineai-ibus diversa.
2. U. Do«/®««, Boott ; spica elongata lineari nuda apice masciüa conformi, stigmatibus 3, perigyniis (arista
^ brevioribus) lanceolatis convexo-concaviusculis basi obconico attenuatis ore tnmcato plmfinerviis margine scabris
superne püis appressis utrinque exasperatis pallichs squama amplectente ovata acuminata obtusa flavescenti-viridi
angustioribus sublongioribusque. Boott.
Hab. Ins. Juan Fernandez. David Douglas. {Herb. Hooker.)
Culmus bipedalis, gracüis, lævis, nudus, basi foliatus. Folia l- l-^ lin. lata, culmo longiora, utrinque marginibusque
scabra. Spica 6 poü. longa, lineam lata, pars suprema masciüa, subpoUicaris, confonnis. Squamæ
ovatæ, acuminatæ, obtusæ, amplectentes, flavescenti-vhides, striatæ, mai-gine paUide-feiTUgineæ, perigynio vix
longiores, omnes conformes. Ferigynium 2-4—3 lin. longum, -^-üu. latum, lineare, hinc convexum, iude concavius-
culum, basi obconico-attenuatum, dorso plurinervium, margiuibus e basi scabnim, püis sursum longioribus, superne
pilis brevioribus appressis utrinque exasperatum, pallidum, lineolis fen-ugineis maculatum, ore truncatiun. Achænium
1 -| lin. longum, liu. latum, liueai-e, convexo-concaviusculum, facie dorsali Imea centrali (ángulo) notatum,
castaneum, impresso-punctiüatum. Arista 3—§• hn. longa, pallida, filiformis, apice ferruginea, perigynio \ longior.
Stylus inclusus. Stigmatibus 3. Boott.