This family, considered to be most nearly related to the Cycadeæ, also
made its appearance at a very early period. There is only one order.
Order. =Taxaceæ.= The characters have been given above.
_A._ CEPHALOTAXEÆ is the oldest group, presumably the connecting
link between the Cycadeæ and the other Coniferæ. The flower consists
normally of two ovules. Aril wanting. One integument. Seeds
drupaceous.--The flowers in _Ginkgo biloba_ (_Salisburia_) are situated
in the axil of foliage- or scale-leaves. The stamens bear only two
pollen-sacs (Fig. 260 _A_). The female flower has two ovules, placed
together at the end of a long, bare axis (Fig. 260 _C_). Round the base
of the ovule a small collar (_ar_, in Fig. 260 _D_) is found, which
may probably be considered homologous with the collar-like outgrowth
which surrounds the base of the _Cycas_-ovule. The seed resembles a
Plum, and has a fleshy external coat, surrounding a hard internal
layer. The embryo is developed after the seed has fallen off. The
Ginkgo-tree has long-stalked, fan-shaped leaves, more or less indented,
with dichotomous veins resembling certain Ferns--the Adiantums. It is a
native of East Asia, and the only surviving species of a genus which in
earlier times was very rich in species, and distributed over the entire
Northern Hemisphere. _Cephalotaxus_ (Eastern Asia) is related to it.
[Illustration: FIG. 260.--_Ginkgo_ (nat. size): _A_ a branch with
a small flowering dwarf-branch (male flower); _B_ a leaf; _C_ a
flower with two ovules; _D_ a ripe seed; _ar_ collar.]
[Illustration: FIG. 261.--_Phyllocladus glaucus_: a branch with
female flowers (nat. size).]
_B._ PODOCARPEÆ. The female flower is reduced to one ovule, placed in
the axil of a bract, or a little forward upon it. The ovule has an
aril (2 integuments).--_Phyllocladus_ (Fig. 261), from New Zealand and
Tasmania, has obtained its name from its flat, _leaf-like branches_,
the leaves proper being scale-like (_f_). The ovules stand _erect_ in
the axil of the scale-like leaves (_c_), and several are collected at
the end of short branches.--_Microcachrys tetragona_ (Tasmania) has
a small female catkin with several spirally-placed, fleshy bracts,
at the end of which the inward and downward turned ovule is attached
(Fig. 262 _A_, _A’_). The ripe cones are red, succulent, and resemble
Strawberries.--In _Dacrydium_ (Tasmania, New Zealand, Malaysia) the
female cone has most frequently only 1–2 (–6) bracts, which resemble
the vegetative leaves; they have also a fleshy aril (Fig. 262 _B_,
_B’_).--_Podocarpus_ (40 species, East Asia, S. Temp.); the bracts of
the female flowers become fleshy, and unite together; only 1 or 2 are
of use in supporting the flowers. The ovules project high above the
apex of the bract, and are _anatropous_, the micropyle being turned
downwards (Fig. 262 _C_, _D_). An aril commences to develope in the
flowering period as an external coating, and later on it becomes fleshy
and coloured.
[Illustration: FIG. 262.--_A Microcachrys_: female cone (2/1).
_A’_ A single carpel with its ovule. _B Dacrydium_: branch with
female flower (3/1). _B’_ The flower; _cp_ the bract; _ar_ the
aril; _ov_ ovule. _C Podocarpus_: female flower with 2 ovules.
_D_ Another female flower with 1 ovule, in longitudinal section.]
[Illustration: FIG. 263.--_Taxus baccata_: branch with two ripe
seeds (nat. size).]
_C._ TAXEÆ. The female flower is reduced to one ovule, which is
situated _terminally_ on an axis which bears 2–3 pairs of opposite,
scale-like bracteoles; on this account the Taxeæ form a very isolated
group among the Coniferæ.--_Taxus_ (_T. baccata_, the Yew-tree).
_Diœcious_. _The female flower consists of only one ovule_, placed _at
the end_ of a short secondary branch (Fig. 264), which is studded with
scale-like leaves. The aril when ripe is thick, fleshy, and scarlet
(sometimes yellow), and only loosely envelopes the seed (Fig. 263).
The leaves are scattered, flat, linear, and pointed (Fig. 263, 264).
The short male flowers have 5–8 pollen-sacs, pendent from the stamens,
and are surrounded at their bases by scale-like bracteoles (Fig. 243).
_Torreya_ (4 species, N. America and Japan) is closely allied to
_Taxus_. The aril ultimately fuses with the woody inner integument, and
hence the ovule becomes drupaceous, as in Cephalotaxaceæ.
[Illustration: FIG. 264.--_Taxus baccata_: _A_ shoot of _Taxus_
with female flowers at the time when the ovules are ready for
pollination. _B_ Leaf with flower in its axil (nat. size). _C_
Longitudinal median section through a female shoot; _v_ growing
point of primary shoot; _a_ commencement of aril; _i_ integument;
_n_ nucellus; _m_ micropyle.]
USES. _Taxus baccata_ is usually planted in gardens, especially
in hedges. Its wood is very hard and is used for wood-carving.
The shoots are poisonous, but not the aril, which is often eaten
by children and by birds.