A key to structural, physiological, and systematic botany

Leafy arborescent plants, with leafy crumpled

cotyledons

Leafless, herbaceous, insipid plants Alliance 5. Pencales. Carpels several.

150. Illigeraceæ Blum. . 151. Cassythaceæ.

Their tubular calyxes distinguish them at once from all the other groups, except Columnosæ; and the latter are in general clearly characterised by their stamens united into a column. Tubiferosæ

152. Penæaceæ

Sweetish, nauseous, gummy, resinous (Sarcocol).

touch Achlamydosæ by Lauraceæ, and Columnosæ by Aristolochiaceæ. They are also strongly related to Curvembryosæ by Elæ

agnaceæ.

Alliance 1. Chenopodales. Albumen present. Radicle next the hilum.

Wholesome, insipid.
Ditto (Spinach).
Emetic.

Alliance 4. Sclerales. Tube of the calyx

Border of the calyx herbaceous
Border of the calyx petaloid
Alliance 5. Cocculales. Albumen present.
Albumen present.
mydeous.

Radicle away from the hilum.

158. Polygonacea

Cotyledons spiral.

159. Petiveraceæ.

hardened.

In their technical character Sclerales seem to approach Tubiferosæ,
they have not, however, much relation to them, and the resemblance
in their calyx is overcome by the structure of the seed. Nyctaginacea
require a much more careful examination than they yet have received.
Menispermaceæ have, strictly speaking, both calyx and corolla; but
their organs are so small and so much alike, that I have no hesitation
in placing the order here; it has but little apparent relation even to

The mutual relations of these groups may be expressed as follows:-
1. Rectembryosæ pass into Achlamydosæ through Garryaceæ, &c.

2. Achlamydosæ

Tubiferosæ

Monimiaceæ.
Aristolochiacea.
Menispermaceæ.

Acid (Sorrel); purgative and tonic (Rhubarb).

Roots purgative.

Flowers formed upon a ternary plan, dichla

162. Menispermaceæ

. Root bitter, tonic (Calumbo);
seeds narcotic (Cocculus).
Schizandreæ among Anonales, beyond the circumstance of the parts of
its flower being ternary, while it seems closely allied to Aristolochiaceæ.
Menispermaceæ must be considered one of the natural orders among
Exogens which tend towards Endogens. The passage of Curvem-
bryosæ into Rectembryosæ through Chenopodiacea on the one hand,
and Urticaceæ on the other, is obvious.

The subclass of Incompleta may be considered allied with other parts of the system in the following manner, viz. : With Polypetale through Daphnales

Chenopodaceæ.

With Monopetalæ

Their true relations will therefore be thus,

Proteaceæ

Lauraceæ
Empetraceæ
? Nyctaginaceæ
Chloranthaceæ

Menispermaceæ
Aristolochiaceæ

to Rhamnales.
Loranthaceæ.
Myristicaceæ.
Euphorbiaceæ.
Solanaceæ.

Gnetaceæ
Smilaceæ.

Araceæ.

1. POLYCARPOSE. Flowers hypogynous (rarely epigynous). Ovary composed of many carpels. 2. EPIGYNOSÆ. Flowers epigynous. Ovary composed of two or many carpels.

3. AGGREGOSÆ. Ovary consisting of but one perfect carpel.

4. LABIOSE. Flowers hypogynous unsymmetrical. Ovary composed of two carpels.

5. DICARPOSE. Flowers hypogynous and symmetrical. Ovary composed of two carpels.

Alliance 2. Ericales.

Seeds winged. Herbs

163. Brexiaceæ.

Anthers opening by pores. Carpels from four to five, or more.

Brown, leafless, parasites

Anthers two-celled. Seeds wingless Anthers two-celled. Ovary inferior Anthers one-celled

Alliance 3. Primulales. Anthers bursting longitudinally. Carpels four-five.

Herbaceous plants. Stamens opposite petals Woody plants. Stamens opposite petals. Milky plants. Calyx and corolla double

Watery plants, with twice as many stamens as petals 172. Ebenacea

Watery plants, with the same number of stamens as sepals

Alliance 4. Nolanales. Fruit divided into deep lobes.

Astringent. Fruit eatable. . Resinous, astringent, aromatic (Storax, Benzoin).

Astringent, tonic (Holly).

172. § Styraceæ

173. Aquifoliacea

Carpels five, or more.

174. Nolanaceæ, m.

175. Cuscutaceæ, m. 176. Convolvulaceæ

Alliance 5. Volvales. Carpels from two to four.

Leafless plants. Embryo spiral
Twining plants, with a plaited corolla

Erect plants, with an imbricated corolla and three carpels

Styles numerous.

Seeds indefinite

Nolanaceæ adjust these to Dicarposæ, and Primulaceae to Epigy-
Ebenacea touch upon Guttaceæ, and Myrsinaceæ upon
Rhamnacea through the genus Choripetalum. Ericaceæ moreover

nosæ.

177. Polemoniaceæ.

178. Hydroleaceæ.

have an evident affinity with Rutaceæ, first through Ledum, which
compared with Phebalium, and secondly through Andromeda,
be
may
which simulates Corræa.

Alliance 5. Stellales.

186. Cinchonaceæ

. 187. Lygodysodiaceæ.

Seeds definite in number.

188. Caprifoliacea

Fruit double. Leaves whorled, with no stipules.

It is evident that in this group, Stellaceæ have a close relationship with Umbellaceae; and that this approximation is participated in by Caprifoliaceæ, through the genera Viburnum and Sambucus. Some

189. Stellaceæ

. Astringent, dyes (Madder.) Primulaceæ seem to approach Cinchonacea; and the Goodenal alliance, by means of Scævolaceæ, passes directly into Brunoniaceæ among Aggregosæ.

Corollas all ligulate. Milky

. 190. Calyceraceæ.

191. Mutisiaceæ.

Involucre hemispherical. Flowers of ray ligulate. 193. Asteraceae

Involucre rigid or spiny, conical. Flowers of ray

Narcotic (Lettuce).

. Bitter, tonic (Chamomile) diuretic.

194. Cynaraceæ

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