CLASS X.

DECANDRIA.

TEN MALES.

THE tenth class is denominated DECANDRIA*. It contains those hermaphrodite flowers which are furnished with ten stamens, or male organs. But this circumstance alone is not sufficient to distinguish the plants of the class Decandria from all the other classes of hermaphrodite vegetables. Other circumstances, or characters, which will be particularly attended to in treating of the classes Monadelphia, Diadelphia, Syngenesia, and Gynandria, must be carefully attended to. It is proper, however, to observe, in this place, that in order to constitute a pure Decandrous plant, it is necessary that the ten stamens be distinct from each other, that is not united together either by their filaments below, or by their anthers abovet.

THE class Decandria is subdivided into six orders. These orders like all the orders of the preceding nine classes, and of the three succeeding classes, are formed from the circumstance of the number of the styles, or female organs. The orders are MONOGYNIA, DIGYNIA, TRIGYNIA, TETRAGYNIA, PENTAGYNIA, and DECAGY

NIA.

→ From Sexa, ten.

† Milne and other writers inform us, that the stamens of the plants of the class Decandria, must be of an equal length. But this circumstance is of little or no consequence in investigating the Decandrous plants, many of which have their stamens of unequal lengths, such as Rhododendron, Rhodora, &c.

F

MONOGYNIA.

ONE FEMALE.

THIS first order is by far the most extensive of the whole. The following are a few of the genera which it contains: Sophora, Podalyria, Anagyris, Cercis, Bauhinia, Poinciana, Myroxylon, Parkinsonia, Cæsalpinia, Toluifera, Cassia, Guilandina, Dictamnus, Adenanthera, Hæmatoxylum, Melia, Swietenia, Guajacum, Ruta, Zygophyllum, Quassia, Limonia, Monotropa, Clethra, Pyrola, Ledum, Dionæa, Melastoma, Andromeda, Rhododendron, Kalmia, Rhodora, Epigæa, Gaultheria, Arbutus, Styrax, Inocarpus, Cassuvium, Samyda, Copaifera, and others*.

DIGYNIA.

TWO FEMALES.

THE second order contains the following genera: viz. Scleranthus, Trianthema, Chrysosplenium, Hydrangea, Saxifraga, Tiarella, Mitella, Cunonia, Saponaria, Dianthus, &c.

* The genera Rhododendron, Kalmia, Rhodora, and Ledum are the Decandrous plants of Jussieu's order Rhododendra. Azalea and Itea (Pentandrous plants), Menziesia (of the class Octandria), and Befaria (of the class Dodecandria) belong to the

same fine order.

TRIGYNIA,

THREE FEMALES.

CUCUBALUS, Silene, Stellaria, Arenaria, Malpighia, Banisteria, and others, belong to this order.

PENTAGYNIA.

FIVE FEMALES.

AVERRHOA, Spondias, Cotyledon, Sedum, Penthorum, Bergia, Oxalis, Agrostemma, Lychnis, Cerastium, and Spergula, belong to this order. Some species of Oxalis belong to the xvith class. One species of Lychnis (Lychnis dioica) belongs to the xx11d class. Lychnis alpina and L. quadridentata have often only four styles.

DECAGYNIA.

TEN FEMALES.

THIS is the most inconsiderable order of the whole. It contains the genera Neurada and Phytolacca. The latter is a very irregular genus. The species which

causes the genus to be arranged in the present order is the P. decandra, or Common Poke. A second species belongs to the vi11th class; a third to the x11th, and a fourth to the xx11d class.

CHARACTER.

Ar the very head of this great class, we find Sophora, Anagyris, and some other genera, which belong to Linnæus's thirty-second order, Papilionacea, of which I shall make more particular mention, when treating of the plants of the xvIIth class. Cercis, Bauhinia, Hymenæa, Poinciana, Myroxylon, Parkinsonia, Cæsalpinia, Cassia, Guilandina, Adenanthera, Hæmatoxylum, and some others, belong to the thirty-third order, Lomentacea*, so called because several of the genera which it embraces furnish fine tinctures that are used in dying. Such are different species of Casalpinia, or Brasiletto; the Guilandina Moringa, the wood of which dies a fine blue colour; Hæmatoxylum Campechianum, called Logwood, or Campeachy-wood, &c. Melia, Swietenia, Malpighia, Banisteria, together with Esculus, and Tropæolum, and some other genera, which have already been mentioned in treating of preceding classes, belong to the twenty-third of Linnæus's natural orders, the order Tribilatat. Guajacum, Tribulus, Fagonia, Zygophyllum, Quassia, Dionæa, Oxalis, Averrhoa, and others, belong to the order Gruinales, which will be

* Lomentacea, from lomentum, a colour used by painters.

+ Tribilata, from tres, three, and hilum, the eye, or external sear of the seed already mentioned. Several of the vegetables of this order have three seeds, which are distinctly marked with an external cicatrix, or scar, where they are fastened within the fruit.

more particularly noticed when treating of the xvith class. Clethra, Pyrola, Ledum, Andromeda, Rhododendron, Kalmia, Epigæa, Gaultheria, Arbutus, Styrax, together with Azalea, Vaccinium, Erica, and others, which are afterwards to be mentioned, constitute the order Bicornes. I have already made some mention of this order*.

LINNÆUS asserts, that there is no poisonous plant in the order Bicornes, unless, perhaps, the genus, Ledumt. ALIQUANDO BONUS DORMITAT HOMERUS. Some of the Bicornes are very poisonous vegetables, such are Kalmia latifolia and angustifolia, some species of Azalea, Andromeda, &c. Epigæa repens is said to be poisonous to sheep. Gaultheria is not an inert plant. I can say nothing certain concerning Clethra and Rhodora. I shall have occasion to speak of the properties of other Bicornes, when treating of the sexual classes to which they belong. From several of the plants of this order, bees obtain an abundance of honey, which, in some species, is endued with a noxious quality‡. Linnæus is, certainly, incorrect, when he asserts, that Kalmia is the only genus among the Bicornes, that is furnished with nectaries. Gaultheria procumbens, not to mention others, has these parts.

Hydrangea, Chrysospleniun, Saxifraga, Tiarella, Mitella, Cotyledon, Sedum, Penthorum, Bergia, together with Heuchera, formerly mentioned, and several

See page 36.

+"Vix quicquam Olidi continet ulla totius ordinis, excepto Ledo, nec ulla vene"nata est, nisi idem forte Ledum, quod tamen incertum adhuc est." Prælectiones, &c. p. 343.

See Part I. p. 152, 153.