Cinnamomum waikatoensis n. sp. Figs. 9 to 13, and 41.
Holotype: Figs. 12 and 41.
Leaf oblong-elliptic, the apex slightly more acute than the base. Margin entire. Midrib well marked; secondaries alternate or sub-opposite, 6 to 8 on either side of the midrib, arising at regular intervals at an angle of about 45° and gently curving forwards and becoming obsolete near the margin; they are prominent and almost parallel. Tertiary veins, shown on Fig. 10, branch towards the margin, arising from the secondary veins at an angle of about 60° and curving forwards. On this specimen also a pair of small veins, probably tertiary, are seen near the base of the leaf.
Figs. 12, 13.—Cinnamomum waikatoensis n. sp. × 1. From Coal Measure Claystones, Pukemiro Colliery.
Figs. 14, 15.—Cassia pluvialis n. sp. × 1. From Coal Measure Claystones, Renown Colliery, Waikokowai.
Fig. 16.—Fagus ninnisiana Ung., × 1. From Coal Measure Claystones, Pukemiro Colliery. [W.H.A.P., del.
This is the most commonly occurring leaf observed by the writer. It has been placed in the genus Cinnamomum because of the occurrence of two well marked opposite secondary veins at the base; and in order to give some means of identification to the leaf the specific name “waikatoensis” has been assigned to it. No form resembling this was collected by Hochstetter or described by Unger, and it has been impossible to find definite relationships with any modern genus in New Zealand. (Cf. C. intermedium, Ettingshausen, 1887, Taf. 4, Fig. 20).
Leaf elliptic, widest in the middle and tapering towards either end. Base acute, apex produced into a rounded protuberance or drip point. Margin entire; midrib prominent. Secondary venation not observable.
No leaf like this has been found among the living New Zealand flora, but it bears some resemblance to C. pseudophaseolites (Ettingshausen, 1887, Taf. 4, Fig. 6) from Shag Point and Murderer's Creek, the apices of which are missing or turned over and buried in the rock. The apices of C. pluvialis were bent over into the claystone and were discovered only by carefully picking out the covering rock.
A fragment without either base or apex, and showing a portion of one side only. Leaf apparently broadly elliptical. Margin serrate. Secondary veins arise regularly from midrib at an angle of about 60°, and terminate in the indentations within the marginal teeth.
Distance from midrib to margin, 19 mm.
Estimated size of leaf, 72 × 38 mm.
This leaf is similar to those collected by Hochstetter from beds of about the same age at Drury and classed as F. ninnisiana by Unger (Figs. 24–32), and for the want of better specimens has been taken as belonging to the same species.
Unger compared F. ninnisiana with F. obliqua Mirb. and with F. procera Pöpp., recent species from Chile, which vary not only in size and shape but also in the marginal teeth exactly as do the fossil leaves. The longer petiole in the fossil leaves (Figs. 24 and 25) may be due to especially strong root force, although in other cases (Figs. 28 and 31) the size is not abnormal.
“It is remarkable that a plant form with its related kinds, which occurs in South Chile, Patagonia, Tasmania, and New Zealand, appears also in the Tertiary flora of these countries as well as in the Tertiary flora of the Northern Hemisphere. This may be an indication that the stock of Fagus originated in and spread readily from the Southern Hemisphere. What is particularly remarkable is that the large leaved kinds of this genus, with the folded bud
position of the leaves, as also the small leaved kinds with mostly leather-like leaves, are represented in the Tertiary flora, while New Zealand at present possesses only the latter kind.” F. ninnisiana occurs also at Shag Point, Otago, and was described by Ettingshausen (1887, p. 24, and Taf. 4, Fig. 1; 1890, p. 270, and Pl. 27, Fig. 1).
Beilschmiedia tarairoides, n. sp. Figs. 17 to 19, and 43.
Holotype: Figs. 19 and 43.
Leaf broadly elliptic, margin entire. Midrib broad, prominent and prolonged into a thick petiole. Secondaries alternate or subopposite, arising at rather wide intervals at an angle of about 50° and arching forwards. They terminate near the margin and nearly parallel to it, and sometimes bifurcate at their extremities. Tertiary veins cross between the secondaries and nearly at right angles to them.
Breadth of largest leaf (Fig. 19) is 65 mm. The most similar leaf among the existing New Zealand flora is that of Beilschmiedia tarairi, and accordingly the fossil form has been given the specific name tarairoides.
A fragment of a large leaf without either base or apex. Leaf oblong elliptic. Margin imperfectly preserved, but apparently entire. Midrib well marked, and in this specimen, which shows the under surface of the leaf, is characteristically ribbed longitudinally. Secondary veins branch from the midrib at irregular intervals and are not always parallel. They leave the midrib at an acute angle but soon bend round to an angle of 65° to 70° and near the margin curve forwards again. Tertiary venation not observable. Maximum width of leaf 68 mm.
Unger (1864, p. 11) described a small fragment (Fig. 36) of a large leaf under the name Phyllites purchasi, which could not be compared with leaves of living or fossil plants. Comparison of
Figs. 20 and 36 shows that these fragments are probably of the same kind. Moreover, the larger fragment collected by the writer is almost identical with leaves of the recent Pisonia brwnoniana now living in North Auckland. The fossil leaves are accordingly placed in this genus and Unger's specific name retained.
Pisonia oliveri n. sp. Figs. 21 and 42, Holotype.
A fragment of a large leaf without base and apex. Leaf oblong elliptic, the apex probably slightly more acute than the base. Margin widely crenate. Midrib well marked. Secondaries alternate, parellel, branching from midrib at an angle of about 65° and sometimes bifurcating once and occasionally twice near the margin.
Fig. 22.—Coprosma pseudoretusa n. sp. × 1.
Fig. 23.—Geniostoma apiculata n. sp. × 1. From Coal Measure Claystones, Pukemiro Colliery. [W.H.A.P., del.
Estimated dimensions, 255 × 112 mm.
This leaf differs specifically from P. purchasi (Ung.) in the secondary venation and in the margin but it still has strong affinities with the genus Pisonia.
Coprosma pseudoretusa n. sp. Fig. 22, Holotype.
Leaf obovate. Margin entire. Secondary veins are alternate, straight and parallel, and branch from midrib at an angle of 45° to
50°. They anastomose near the margin and the tertiary venation, which is partly preserved, probably consists of a coarse network joining the secondaries. Dimensions, 75 × 34 mm. This leaf is very similar to the recent C. retusa.
Geniostoma apiculata n. sp. Fig. 23, Holotype.
Leaf oblong elliptic; apex produced into a blunt point. Margin entire. Midrib and secondary veins well marked, the latter alternate, parallel and curving regularly forwards. The tertiary venation on this leaf is remarkably well preserved and consists of a fine network into which the ends of the secondary veins merge.
Dimensions, 95 (estimated) × 39 mm.
The following leaves collected by Hochstetter, were not found by the writer in the Coal Measure Series of the Waikato district, but their occurrence near Drury in beds of approximately the same age justifies their mention in this paper. Most of the leaves are so fragmental that comparison with existing forms would be without benefit because of the probable inaccuracy involved.
Loranthophyllum dubium Ung. Figs. 33 and 34.
This leaf was named from its similarity to L. griselinia Ung. (1864, pp. 8-9, Taf. 3, Fig. 13) and to Loranthus longifolius Deso. A remnant of a stem (Fig. 31) from the same locality shows the original opposite positions of the leaves and the protruding leaf cushions such as occur also on the stem of L. longifolius (Fig. 32).
Myrtifolium lingua Ung. Fig. 37.
Unger found no resemblance to this well preserved leaf among either fossil or living forms. There is no known living form similar to this in New Zealand.
Phyllites laurinium Ung. Fig. 38.
This leaf scrap bears some resemblance to Laurum princeps, “but that does not in the slightest degree mean its complete accord.”
Phyllites ficoides Ung. Fig. 39.
This was compared doubtfully with the leaves of some kinds of Ficus. (A smaller fragment from the Pukemiro Mine appears to be from the same kind of leaf).
Phyllites novae-zelandiae Ung. Fig. 40.
Unger found no similarity of this leaf with leaves of New Zealand trees and obtained no true identification with other living or fossil leaves.
These dicotyledonous leaves belong to forest trees and shrubs the modern representatives of which are confined to warm temperate or subtropical regions. They have a general Malayan character. An attempt to determine the probable plant associations from this small collection would be unwise. If more types are in the future discovered it may then be possible to reconstruct the flora which contributed the vegetable debris now constituting the coal seams of the district, although fossil leaves are but poor material for botanical
classification. At present the only safe conclusions are those concerning the climate and the predominantly angiospermous nature of the flora.
The latter characteristic is of great importance because it influences the nature of the peat formed from this type of vege-
tation, and hence that of the resulting coal. From the leaf remains collected by the writer, and also by Hochstetter and others, it can be deduced that the swamp was of the wooded or forested type in which angiosperms were the dominant form, though conifers were
Figs 33, 34.—Loranthophyllum dubium Ung. × 1. (33.) Piece of leaf. (34.) Piece of a twig with strongly protruding leaf cushions. From Mr. Fallwell's place near Drury, in a light grey, greasy claystone.
Fig. 35.—Loranthus longifolius Sprgl. × 1. Piece of twig for comparison with Fig. 34.
Fig. 36.—Phyllites purchasi Ung. × 1. From Mr. Fallwell's place near Drury, in a light grey, greasy claystone. [After Unger.
present in subordinate amount as evidenced by the occurrence of resin. According to Thiessen (1928, p. 38), “Peat formed from the wooded swamp is of particular interest because it appears to be analogous to most of the bituminous coals and to many lignites
Fig. 37.—Myrtifolium lingua Ung. × 1.
Fig. 38.—Phyllites laurinium Ung. × 1.
Fig. 39.—Phyllites ficoides Ung. × 1. These are from Mr. Pollock's Spring Hill Shaft near Drury, in a firm ferruginous sandstone.
Fig. 40.—Phyllites novae zelandiae Ung. × 1. From Mr. Fallwell's place near Drury, in light grey, greasy claystone. [After Unger.
and sub-bituminous coals. Each peat deposit that results from the different types has a distinct character. The greatest distinction is to be found in peat derived from angiosperms (the ordinary leafy trees) and that from conifers.” He states further that “the angiosperms yielded readily to decay and disintegration, leaving little more than an amorphous muck or attritus; the conifers, on the other hand, wherever present, resisted decay and maceration to a far greater extent, due to their toxic resinous contents, and left a large proportion of better-preserved woody material.” Coals derived from a coniferous flora are therefore always woody, whereas those derived from an angiospermous flora are always more or less amorphous. The two types are readily distinguished.
The coal from the Waikato district has the amorphous appearance described by Thiessen. It consists mainly of a relatively dull matrix in which are embedded small strips of bright coal (the “anthraxylon” of Thiessen) though in small amount only. Rarely are large strips of bright coal seen (see Penseler, 1930a).
The reason for the present characteristics of the Waikato coal is thus clear. Its origin in a freshwater wooded swamp from a predominantly angiospermous flora is evident from the palaeobotany and the geological history of the Coal Measure Series. From this type of flora, a characteristically Tertiary one, coal of a special nature is to be expected, and this expectation is confirmed by an examination of the Waikato coal.