# Edwards's Botanical Register/Appendix to the first twenty-three volumes/A sketch of the vegetation of the Swan River Colony/Miscellaneous Exogens

Miscellaneous Exogens.
There are no other orders of Exogens sufficiently remarkable, as to the proportion they bear to the rest of the Flora, to require especial notice; but there are several genera belonging to different orders, concerning which it is desirable to make a few observations.
Of the beautiful genus Tetratheca there are many species, all apparently peculiar to the colony; and, what is curious, belonging to the pentamerous division of the genus.
​Of these T. viminea$^{184}$ has long smooth slender branches, slightly covered with smooth ovate whorled leaves, and bright purple flowers drooping from the end of the branches; T. rubriseta$^{185}$ is a bush loaded with purple or rose-coloured flowers, and often clothed with bright red hairs; T. nuda$^{186}$ is a naked plant, looking like a rush when out of flower, but producing a great quantity of most brilliant crimson blossoms; T. hirsuta$^{187}$ and pilifera$^{188}$ are also pretty shrubs, but not to be compared with the others for gay appearance. Most of them would be great acquisitions to our gardens.
Four or five species of Comesperma are met with, one of which seems undistinguishable from the blue-flowered twining C. volubilis of the south coast; and another is the beautiful C. conferta. Lab., an herbaceous plant, or under-shrub, clothed with narrow rigid leaves, and loaded with erect racemes of violet flowers, succeeded by the curious spathulate emarginate fruit of the genus.
Of Brassicaceæ only two genera have been remarked in a wild state; the one Lepidium, the other Stenopetalum; the latter consists of three or four species, with long spirally twisted petals, but they are none of them of any Horticultural interest.
A few Stackhousias are met with, but they are species of no beauty; any more than the singular genus Tripterococcus, with its triple-winged sharp-pointed fruit, which seems peculiar to this locality.
There is a suffruticose Violaceous plant, with narrow
$^{(184)}$ Tetratheca viminea; glabra v. basi caulis subpilosa, foliis ovato-oblongis rotundisve verticillatis sparsisque internodiis multò brevioribus, floribus pentameris.
$^{(185)}$ Tetratheca rubriseta; ramis pubescentibus nunc pilis rubris hispidis, foliis lineari-oblongis revolutis supra scabris subtùs tomentosis, pedunculis axillaribus corymbosis aculeatis setosis glaberrimisve, antheris scabris longè rostratis, floribus pentameris.
$^{(186)}$ Tetratheca nuda; glaberrima, ramis junceis apice abortientibus, foliis linearibus deciduis plurimis deficientibus, pedunculis sparsis glabriusculis corollæ longitudine, petalis obovatis, floribus pentameris.
$^{(187)}$ Tetratheca hirsuta; ramis tomentosis nunc setosis, foliis oblongis sparsis oppositisve subtùs tomentosis suprà hispidis, pedunculis setosis scabrisve, floribus pentameris.—Near T. rubriseta; flowers pink.
$^{(188)}$ Tetratheca pilifera; ramis pubescentibus setosis, foliis verticillatis ovatis grossè dentatis utrinque glabris: dentibus setigeris pedunculis glabris foliis paulò longioribus, floribus pentameris.—Flowers dark purple.
​entire leaves, and rather handsome violet and white flowers on long erect peduncles, called by Endlicher Pigea glauca; and another downy small blunt-leaved species with white flowers, probably referable to the same genus.
Many Dilleniaceous plants occur, together with two species of Clematis, a Ranunculus (Colonorum, Endl.), and several Apiaceæ of singular but not beautiful forms; there is also Pelargonium littorale, an uninteresting species figured in Hugel's Archiv (t. 5), an Acæna, two Plantagos, a Myriophyllum, and a couple of Boraginaceous plants, resembling Myosotis. To these must be added the singular genus Diplopeltis, of which a plate and full account are given in the Botanical Register for 1839, t. 69.
Nuytsia floribunda (Tab. IV.), a beautiful shrub, with very large thyrses of bright orange-coloured flowers, has already been mentioned (p. iv). It is a singular instance of a plant belonging to the parasitical order Loranthaceæ growing upon the ground. In a manuscript note, communicated to me by Mr. Allan Cunningham, it is stated to flower in the summer months (December and January), and such is the abundance of the orange-coloured blossoms, that the Colonists at King George's Sound compare it to a tree on fire; hence it has gained the name of "Fire tree." A second species (N. ligustrina, A. C.) was found by Mr. Cunningham in 1817 in the more arid parts of the Blue Mountains west from Port Jackson; he tells me it forms a very bushy shrub, three feet high, and flowers usually in the spring of the Colony (October). The only other species of the same order, yet found, is a species of Loranthus, growing parasitically upon the "Black Wattle."
Of Lobeliaceæ there are only three of any interest for their beauty, and we already possess them in our gardens. L. heterophylla and ramosa, the latter a most variable plant, are now common; but the third, Isotoma Brownii, is extremely rare, although its great beauty would render it a most ornamental plant. The figure of it under the name of Lobelia hypocrateriformis in the Botanical Magazine, fig. 3075, was taken from a starved specimen, and gives no idea of its appearance. In its native state the stem is as thick as a swan's quill, one and a half to two feet high, and in one of my specimens has above forty flowers all open at once; the colour in the Botanical Magazine, viz. a rich violet
​with a crimson eye, like Phlox Drummondi, seems to be correct.
Among Monopetalous Exogens not yet noticed, there are but few remarkable plants. Anthotroche pannosa, Endl., is a singular shrub, buried in wool, from among which the deep purple flowers peep forth. Mallophora globiflora, Endl., bears little balls of wool, studded with the points of its white flowers; the style of this plant is certainly divided into two deep filiform lobes, and is not entire as it is described. Of Hemiandra, a genus of labiate, herbaceous, or half-shrubby plants, with ribbed pungent leaves and purple flowers, of which one (H. rupestris) has been introduced by Baron Hugel, there are several handsome species; Hemigenia, another genus of the same natural order, is also met with; together with Atelandra,$^{189}$ a new genus, differing from both these in its calyx and in habit. Two species are known, with hoary leaves and apparently purple flowers; of which A. incana (Tab. V. A) seems the finest. Two species of the rare genus Halgania have been sent home, both different from those recently described by Endlicher; one of them, H. cyanea,$^{191}$ is a hispid plant, perhaps an annual, with axillary blue flowers on long stalks, but of no beauty; the other, H. corymbosa,$^{192}$ is a brilliant herbaceous plant, with long-stalked terminal corymbs of purple flowers.
Of Apetalous Exogens the greater number belong to Pimelea and Trichinium; but, with the exception of T. Manglesii, Stirlingii, and alopecuroideum, few of the latter genus are of much beauty, and I find but one Pimelea which
$^{(189)}$ Atelandra (Lamiaceæ). Calyx bilabiatus, mollis: labio superiore 2-, inferiore 3-dentato. Corolla tube brevi, limbi labio superiore latiore emarginato, inferioris 3-partiti lacinia intermedia majore concavo. Stamina 4; inferioribus longioribus. Antheræ glabræ, loculo altero ascendente pollinifero, altero descendente casso. Styli laciniâ superiore minima.
Atelandra incana (Tab. V. f. A); foliis oblongis incanis sericeis, floribus axillaribus solitariis.
$^{(190)}$ Atelandra polystachya; foliis oblongo-lanceolatis tomentosis subtùs venosis, spicis axillaribus imbricatis, filamentis basi villosis.
$^{(191)}$ Halgania cyanea; hispido-pilosa, foliis oblongo-linearibus serratis, pedunculis axillaribus unifloris foliis longioribus, calycibus adpresso-pilosis: laciniis acutis.
$^{(192)}$ Halgania corymbosa; pilosa, foliis cuneato-oblongis grossè serratis basi integerrimis, corybis pedunculatis multifloris, calycibus villosis: laciniis obtusis.
​promises to be ornamental; that one, however,$^{193}$ is a noble plant, with spherical heads of pink flowers six inches in circumference, and a compact handsome foliage.
Finally, there is an exogenous plant to which I must particularly allude, in consequence of its very singular structure. This, which seems to be herbaceous, has a round purple stem, clothed near the base with linear striated alternate leaves, and dividing at the top, which is nearly leafless, into a corymbose compact panicle of bright yellow flowers. The calyx is superior and four-toothed; there are four petals with an imbricate aestivation; within these are eight stamens with linear bi-locular anthers; there is no trace of disk; the ovary is one-celled, and has four membranous wings opposite the petals; there are four short erect styles, each with a discoloured rounded stigma, and the ovules are one or two, anatropous, hanging by short funiculi from the apex of the cavity, one on each side of a slender cord which passes from the apex to the base of the cell. Some of these characters are so much those of Combretaceæ, that the genus might appear referable to that order, if its habit were not opposed to such an approximation, which its four styles render still more objectionable, notwithstanding the correspondence of its winged fruit with that of Pentaptera. It may also be compared with the genus Quinchamalium, usually referred to Santalaceæ, with which its unilocular ovary and general habit very much agree, especially if we suppose that in the plant under consideration the cord that separates the two pendulous ovules answers to that which bears the ovules at its own apex in Quinchamalium; the four distinct styles however, and the absence of a disk, are materially at variance with that genus, although not with some other plants of the same order. It is however among those degenerate forms of Onagraceæ, known by the name of Halorageæ, that the most immediate afiinity of the plant is probably to be sought, and especially with Cercodea, by some authors referred to Haloragis; with that genus it corresponds in having a winged
$^{(193)}$ Pimelea spectabilis; foliis oppositis lineari-oblongis acutis sessilibus glaucis ramisque glaberrimis, capitulis sphæricis sessilibus multifloris, calycis limbo sericeo: tubo villosissimo, involucri foliolis ovatis acuminatis coloratis.
​fruit, petals similar in form, stamens twice the number of the petals, definite pendulous ovules, and four distinct styles; but it differs from Cercodea and Haloragis in the ovary being one-celled in its original structure, and in the æstivation of the corolla being imbricated, not valvate. It is probable that the fruit, when it shall be known, will incline the scale of comparison in favour of Halorageæ; but in the meanwhile this brief discussion sufficiently shews the near relationship that exists beween Quinchamalium, Combretaceæ, and Halorageæ, notwithstanding the distance at which the former and two latter are placed in the artificial divisions of the Natural System. I propose to name this very curious and interesting genus Loudonia,$^{194}$ as a tribute to the eminent services rendered to Horticultural Botany by John Claudius Loudon, Esq. author of the Arboretum Britannicum, and of many other valuable works well known in every part of the civilized world. Haloragis cordigera, Fenzl, and probably H. scoparia of the same author, the former of which has two pairs of ovules hanging down from the apex of a single cell in the ovary, and separated, as in the plant under consideration, by a pendulous cord originating between them, may possibly also belong to Loudonia; they certainly have no title to be included in Haloragis. The following cut, which represents Loudonia aurea in flower, will I trust be the means of procuring it for our gardens, or at all events of securing an abundant supply of dried specimens both in flower and fruit for the use of Botanists.
$^{(194)}$ Loudonia (Halorageæ?). Calyx 4-dentatus, superus, tubo tetraptero, a latere verrucoso. Petala 4, cucullata, æstivatione imbricata. Stamina 8, antheris linearibus. Discus 0. Ovarium 1-loculare: ovulis 2, pendulis, anatropis, filo ab apice loculi oriundo sejunctis; styli 4; stigmata rotundata, discolora, lævia.
Loudonia aurea. Glaberrima; caule erecto, tereti, sesquipedali, simplici, glauco, discolore, basi foliato, apice nunc aphyllo. Folia linearia, alterna, coriacea integerrima. Panicula terminalis corymbosa. Bracteæ superiores petaloideæ, obovatæ, floribus aureis æquales, primariæ foliaceæ aut deficientes.
Fig. 1. represents a flower of Loudonia aurea, magnified, after three of the front stamens have been removed.
Fig. 2. is a section of the centre of the ovary, with two stigmas remaining, the two pendulous ovules, and the cord that separates them.