notch, Lat.), Fig. 29: and this may be obtusely crenate, obtuse crenatum, acutely crenate, acute crenatum, or doubly crenate, duplicato-crenatum.

24. FOLIUM ovatum, an ovate leaf. 25. FOLIUM ovale, an oval leaf.

Ovum means an egg, and from it both these terms are derived; but they do not mean exactly the same thing. Draw the figure of an egg on paper-it will be broader at one end than the other, Fig. 30. (a). To the broad end add a petiole, and prolong it into a mid-rib, with some lateral divisions, and the representation will be that of an ovate leaf, FOLIUM ovatum, (b).

But suppose that one end of the leaf is not broader than the other, but that both ends are round, and of equal breadth, then it will be a FOLIUM ovale, (c). Or should the length of the latter be much greater proportionably than the length of an egg bears to its breadth, it will be

Fig. 30.

α

b

d

It often happens in ovate leaves, that the broad end of the egg is uppermost, the petiole being inserted into the narrow end, and hence,

27. FOLIUM obovatum, an obovate, or inverselyovate leaf. The term obcordate is applied in like manner to heart-shaped leaves, when the base of the heart is directed outwards from the stem.

LEAVES WHICH IN SHAPE RESEMBLE INSTRU

MENTS OF WAR.

28. FOLIUM sagittatum, a sagittate, or arrowshaped leaf (sagitta, an arrow, Lat.), Fig. 31. (a)

29. FOLIUM hastutum, hastate, or halberdshaped (hasta, a pike or battle-axe, Lat.), closely allied to the auriculate leaf (b).

Fig. 51.

30. FOLIUM lanceolatum, lanceolate (lancea, a lance, Lat.), oblong, and tapering to each extre

VARIOUS LEAVES.

121

mity, as in ribwort plantain. (Plantago lanceolata.) See (b) Fig. 26.

31. FOLIUM ensiforme, ensiform, or sword-shaped (ensis, a sword, Lat.), as in iris.

32. FOLIUM acinaciforme, acinaciform, or scimitar-shaped (axivaxnç) (akinakes) a scimitar (Greek); like a Persian scimitar, one edge convex and sharp, the other straight and thick. Fig. 32. (a) 33. FOLIUM peltatum, a peltate, or target-shaped leaf (pelta, a shield, buckler, or target, Lat.).

In peltate leaves the petiole, in place of being inserted into the margin of the leaf, is implanted on its under surface, at or near its centre. The nasturtium, or Indian cress, cultivated every where in gardens, is a familiar example; and also the ivy-leaved geranium (Geranium peltatum). (b)

In many peltate leaves the upper surface is tucked in, or hollowed towards the middle; and on this account they have been termed FOLIA umbilicata, umbilicated leaves.

LEAVES THAT RESEMBLE MUSICAL INSTRUMENTS.

34. FOLIUM lyratum, a lyrate, or lyre-shaped leaf (lyra, a lyre or harp, Lat.). A leaf is said to be

G

pinnatifid when it has a number of incisures going nearly to the mid-rib. Fig. 33. (a) Now the lyrate only differs from the pinnatifid leaf in its terminating segment being very large and rounded. (b)

MENTS OR OTHER FAMILIAR OBJECTS.

36. FOLIUM dolabriforme, dolabriform or hatchetshaped (dolabra, an axe, Lat.), like the scimitarshaped leaf, but the sharp edge nearly orbicular. Fig. 34. (a)

37. FOLIUM runcinatum, a runcinate leaf (runcina, a large saw, Lat.), when the margin has its segments and teeth acute, and pointing backwards, like the teeth of a large timber-saw. It is a variety of the pinnatifid, or rather, perhaps, the lyrate leaf. Common dandelion affords an excellent example, Fig. 34. (b)

38. FOLIUM deltoides, or deltoideum, a deltoid, or trowel-shaped leaf (from the Greek letter Delta, A). (c)

39. FOLIUM subulatum, a subulate, or awl-shaped leaf (subula, an awl, Lat.). The awl has generally a bend, but that is not necessary to the subulate leaf. It tapers gradually from base to point, and sometimes is hollow, forming a tubular leaf (FOLIUM tubulosum).

40. FOLIUM acerosum, an acerose leaf.

The simple inspection of the leaf of a yew or firtree will give a better idea of this leaf than words can. It is linear, or subulate, rigid, evergreen, and in the pine and other coniferous plants, is united at its base to the branch by a kind of articulation. Trees of the pine-tribe have been named arbores acerosa, and, in the timber-merchant's phrase, needle timber, from their having, with only a few exceptions, acerose leaves. These trees inhabit naturally, either northern or alpine regions, which habitats explain why they have been instructed with this species of leaf. With that of any other description, they could not have been evergreens, for in winter they would be over