Among the plants of the Apetalous orders in the collection, there are very few remarkable, and hardly any new species.
Gymnocarpus decandrum was observed by Dr. Oudney very commonly in gravelly deserts, on the route from Tripoli to Fezzan; and Cornulaca monacantha of M. Delile is said to be widely extended from Tripoli to Bornou, and to be excellent food for camels.
Monocotyledones. The number of species belonging to this primary division contained in the herbarium is altogether seventy. But Gramineæ and Cyperaceæ being excluded, thirteen only remain, namely, three species of Juncus, a single Commelina, three Melanthaceæ, three Asphodeleæ, one species of Iris, and two Aroideæ, of which Pistia Stratiotes is one.
Of these thirteen plants, two appear to be unpublished, both of them belonging to Melanthaceae. The first, a congener of Melanthium punctatum, which is also in the collection, was found in Fezzan.
The second is a species of Colchicum, very different from any hitherto described; and which yet, by Mr. Ritchie, who first observed it, is said to be common in the desert near Tripoli, where it was also found by Dr. Oudney.
This species, which I have named Colchicum Ritchii, is easily distinguished from all its congeners by having two cristæ or membranous processes which are generally fimbriated, at the base of each segment of the perianthium, parallel to each other, and to the intermediate filament. But this character, though excellent as a specific difference, is neither of generic importance, nor sufficient to authorise the formation of a separate section[118].
Bulbocodium and Merendera, however, which, following Mr. Ker[119], I consider as belonging to Colchicum, appear to me decidedly to form subgenera or sections; and in this opinion I am confirmed by having found a fourth section of the same genus. This fourth subgenus is established on Hypoxis fascicularis, a plant which has been seen by very few botanists, and which Linnæus introduced into his Species Plantarum, and referred to Hypoxis, solely on the authority of the figure published in Dr. Russell’s History of Aleppo. In the Banksian Herbarium I have examined part of the original specimen of this species, found by Dr. Alexander Russell, and figured by Ehret in the work referred to, as well as more perfect specimens collected by Dr. Patrick Russell; and am satisfied that its ovarium is not in any degree adherent to the tube of the perianthium. I find, also, that Hypoxis fascicularis differs from Colchicum merely in having a simple unilocular ovarium with a single parietal placenta and an undivided style, instead of the compound trilocular ovarium with distinct or partially united styles, common to all the other sections of that genus.
A reduction, as in this case, to the solitary simple pistillum[120], though existing in all Gramineæ and in certain genera of several other families of Monocotyledones, is yet comparatively rare in that primary division of phænogamous plants, and in the great class Liliaceæ, the present species of Colchicum offers, I believe, the only known example. Yet this remarkable character is here so little influential, if I may so speak, that Hypoxis fascicularis very closely resembles some states of Colchicum Ritchii, and in the Banksian herbarium has actually been confounded with another species of the first or trigynous section of the genus.
To the first section, which includes Colchicum Ritchii, the subgeneric name Hermodactylum may, perhaps, be applied; while that established on Hypoxis fascicularis may be called Monocaryum.
The position of the pistillum in Colchicum (Monocaryum) fasciculare is not easily determined. I believe it to be placed within the anterior segment of the outer series of the perianthium, but, from the great length of the tube, it is difficult to ascertain such a point in dried specimens. This, however, is the position in which I should expect it, both in reference to the usual relation of the solitary simple pistillum to the axis of the spike, or to the subtending bractea in all phænogamous plants; and also with regard to the constant relation of the parts of the compound pistillum to the divisions of the perianthium in Monocotyledones: for it is worthy of remark, that a difference in this relation may be said to exist in the two primary divisions of phænogamous plants—the pistilla when distinct, or their component parts when united, being in Dicotyledones usually placed opposite to the petals, when these are of equal number; while in Monocotyledones the cells of the trilocular ovarium are, I believe, uniformly opposite to the divisions of the outer series of the perianthium.