82 FLORA ANTARCTICA.
pallide flavo-brunnea, utrinque (chalaza apiceque) fusca, albumin! appressa, exteriore remota ; inter has duas
raphe sæpius solutus apparet. Albumen camosum. Embryo parvus, albidus, oblique tetragonus, in basi albu-
minis immersus, hilo proximus.
This species was, according to Lamarck, originally discovered by Commerson, who accompanied Bougainville
in his voyage to the Straits of Magalhaens, &c. I have gathered it abundantly both in Tierra del Fuego and
the Falkland Islands. In the latter locality it is very abundant, and had been previously detected by M. Gaudichaud
and by Admiral D’Urville. It is rare in Campbell’s Island, and -was not observed upon Lord Auckland’s
group. It is equally distinct from the R . grandiflora {Marsippospermum grandiflorum, Desv., Hook. Ic. Plant,
t. 533) and from the following, in the elongated bractea which subtends the flower, as w'ell as the size of the
plant, form of the leaf and capsule, and curious structure of the seeds. I have no hesitation in retaining
Lamarck’s specific name of Magellanica for this plant, the species being well characterized by that author, and
known to Desvaux at the time he established the genus Rostkovia \ this he did upon different grounds however
from those which induce me to retain it.
M. Desvaux founds the genus on this solitary species, but grounds his generic character on an erroneous
idea of the structure of the capsule, which he describes (Journ. de Bot. 1. c.) as “ capsula globosa, unilocularis,
non dehiscens ; trophospermum suturale ” (p. 326) ; and again in the previous page, “ Je crois que la capsule ne
s’ouvre point; par suite d’une observation générale, c’est que tout fim it qui n’est point anguleux dans aucune de
ses parties, n'est pas déhiscent, surtout s'il est sphérique les graines en grand nombre sont disposées sur
trois trophospermes (placentæ) fixés sur les parois de la capsule et alternant avec les indices de déhiscence qui
s’aperçoivent au milieu des parois des loges, et qui sont toujours indiqués, malgré que cette déhiscence n ’ait
point lieu dans quelques genres de la famille des Joncinées” (p. 325). The capsule of R . Magellanica I have
described as of a very hard consistence, and its dehiscence does not take place until a considerable period after
the apparent ripening of the seeds ; that it does burst is however abundantly evident, and the dehiscence takes
place by three valves, exactly as in Desvaux’s genus Marsippospermum and in other Junceoe, the placentæ occupying
the axis of the valves. From the above extract I conclude that M. Desvaux did not examine fully ripe capsules,
and took the groove at the back of the valves, which is seen in almost all Junci, denoting the position of
the placenta, for the line of dehiscence. In the work alluded to no description of the seeds themselves is given,
though another genus is founded on a supposed peculiarity of structure in that organ. Mr. Brown (Prodr.
p. 258), in his observations on the genus Juncus, remai’ks th a t no dependence is to be placed on the form of the
testa as a generic character, “ nec secernendæ eæ seminibus scobiformibus, testa nempe, quæ in pluribus
utrinque laxa, in his valde elongata and as in the genus Juncus itself there are several forms of that oi-gan,
so in Rostkovia, as it now stands, it differs remarkably in two of the species. In R . grandiflora the outer integument
of the seed is lax and drawn out at both ends, as in Juncus castaneus, Sm., and several other species ;
b ut in the R. Magellanica it assumes a form which I have not seen in any other species of the Natural Order,
forming a very thick, even seed-coat, hard, smooth and shining externally, marked on one side with a prominent
ridge, indicating the position of the raphe ; vrithin it is soft and spongy, with a large cavity. Inside this
the nucleus hangs loose, suspended by the vessels of the raphe, which are more or less detached and often quite
separate from the walls of the seed-coat, except at the base. The inner membrane immediately surrounds the
albumen ; it is thin and membranous, obscurely striated or reticulated, of a pale brown colour with a broad orbicular
dark-coloured chalaza at the summit and another dark spot and apiculus at the pendent apex. This membrane
is quite free from the outer, and analogous to what is generally considered as the testa in many Junci
which are described as not having that organ scobiform, but in which the true outer membrane of the seed, an alogous
to the coriaceous one of the present species, is delicate and hyaline, either altogether deciduous or leaving
a few filamentous residua round the base and apex of the seed, or as in scheuchzerioides, leaving the raphe
as the only attachment betw'een the seed and placenta. In some species of the Order this outer membrane forms
with water a transparent jelly, in which the seed appears immersed ; it is very similar to what is seen surrounding
the moistened achænia of some Compositoe. In South American specimens of R . Magellanica the seeds are
paler and generally angled or compressed ; the vessels of the raphe are also seen entirely detached from the
walls of tbe membranes and running quite free between them to the summit of the albumen covered with the
inner membrane, which thus appears suspended in the cavity of the outer coat, like the seed of some Amaran-
thaceous plant attached to a funiculus.
The R . grandiflora is the type of this genus, to which the name of Marsippospermum was given by Desvaux ;
but from that word denoting a structure in the seed foreign to this species, and not implying a character peculiar
to any group qî Junci, I have substituted that of Rostkovia, to include both these and the following. The
very peculiar habit and appearance of the species, the singularly large and solitary flowers, unlike those of any
Juncus, together with the elongated style and the disproportionate size of the stigmata, are characters peculiar
to all these, and appear of sufficient importance to warrant the retaining them under a separate generic name.
M. Kunth in his ‘ Enumeratio Plantarum’ (vol. iii. p. 356) places the R. Magellanica near Juncus trifidus, L.,
a plant to which it has assuredly no affinity, either in habit, inflorescence, or structure of the capsule. The
R . grandiflora the same author removes to another section, and arranges it (probably following Mr. Brown’s
suggestion) along w'ith J . castaneus, Sm., biglumis, L., triglumis, L., and some others of more dubious affinity,
in a group at the end of the genus.
2 . U 0&TK.OV IA gracilis, H o ok . fil. ; rh izom a te va lid o r ep en te , c iilm is e r ec tis f a stig ia tis g r a c ilib u s,
fo liis solita riis e lon g a tis b a si sq u am o sis e t v a g in a tis filifo rmibus te r e tib u s r ig id is, s c ap is so lita riis folio
te r brevioribus, bra ctea infra-florali solitaria br ev issim a ob tu sa , p e r ian th ii fo lio lis lo n g is s im e la n c eo -
la to -su b u la tis, c ap su la lin e a r i-ob lon g a p e r ian th io m u lto tie s breviore. (T a b . X L V I I .)
H a b . L o rd A u ck la n d ’s g ro u p an d CampbeU’s I s la n d ; am o n g st rocks an d also in m a rsh y
p laces ; common a t an elevation o f 8 0 0 -1 2 0 0 feet.
Rhizomata cæspitosa, intertexta, horizontaliter repentia, 3 -4 unc. longa, valida, crassa, sub ^ unc. diametr.,
dura, lignea, per totam longitudinem et præcipue versus apices culraos perplurimos superne emittentia, reliquiis
foliorum vetustorum ubique vestita, subtus fibrosa; fibris validis, elongatis, 1-2 unc. longis, descendentibus,
curvatis, diametro pennæ passerinæ, copiosissime fibrdlosis. Culmi numerosi, fastigiati, erecti, stricti, teretes,
basi squamosi et vaginati ; squamæ e vaginis junioribus explanatis formatæ, striatæ, nitidæ, castaueæ ; vaginoe
2-3, folium arcte amplectentes,elongatæ, 1 -l^ u n c . longæ, teretes, striatæ, fulvæv. pallide castaneæ, basi brunneæ,
politæ, vernicosæ, ad apices rotundatæ, mucronatæ ; mucrone plus minusve elongato, pungente. Folium solitarium
v. rarius duo, erectum, filiforme, elongatum, |- 1 pedale, gracile, teres, striatum, vix lin. diametr., gradatim
acuminatum, apice subpungente, pallide viride, politum, intus spongiosum, fasciculis 8-10 tubulosis intra-
marginalibus vasorum percursum. Scapus erectus, solitarius, gracilis, teres, 2-3 uncialis, folio bis terve brevior,
infra florem paulo inci-assatus. Flos solitarius, majusculus, erectus, |- 1 unc. longus. Bracteola infra-floralis
solitaria, paiwa, late ovato-oblonga, obtusa, membranacea, sub lineam longa. Perianthium angustum ; foliola longe
lineari-subulata, gradatim acuminata ; exteriora subinæqualia, longiora, et paulo latiora, inferne plana, supra
medium concava, dorso carinata, medio pergamentacea, striata, castanea, nitida, marginibus late scariosis ; interiora
subsimilia sed breviora et angustiora. Stamina breviuscula, foliolis interioribus perianthii | breviora ; fila-
menta brevia, latiuscula, plana, medio uninèrvia ; antheræ filamentis quadruplo longiores, lineari-elongatæ ; connectivo
ultra apicem in unguem obtusum, subrecurvum producto ; loculis parallelis, contiguis, rimis lateralibus
dehiscentibus. Pollen flavum, obtuse tetragonum. Ovariwn elongatum, ovato-oblongum v. subconicum, obtuse
trigonnm v. prismaticum, in stylum gradatim acuminatum, uniloculare, pluriovulatum, staminibus brevius. Placenta
nerviformes, 3-seriales, a valvis facile divulsæ. Ovula plurima, ascendentia, biserialia, funiculis brevibus
placentis adnexa. Stylus rectus, elongatus, validus, ovario æquilongus, superne subincrassatus. Stigmata 3,
majuscula, erecta, basi confiuentia, perianthio inclusa, filiformi-subulata, intus glandulis pellucidis obsita, dorso
M 2