1. Division: Pinophyta / Coniferophyta II

2. Pinophyta / Coniferophyta
Pinophyta Families
Pinaceae – pines & spruces etc.
Cupressaceae – Cypress / Redwood family
Podocarpaceae – Podocarp family
Araucariaceae – Norfolk Isl. Pine family
Taxaceae – Yew family
Cephalotaxaceae
Sciadopityaceae – Umbrella-pine family

3. Phylogeny of the Pinophyta based on cladistic analysis of molecular data.
(Derived from papers by A. Farjon and C. J. Quinn & R. A. Price in the Proceedings of the Fourth International Conifer Conference, Acta Horticulturae 615 (2003))

4. Family: Cupressaceae
It is the most widely distributed of all gymnosperm families, occurring in diverse habitats on all continents except Antarctica
Wetlands  dry soils; sea level  high mountain elevations
Consists of 32 genera and 148 species
¾ of species occur in N. Hemisphere

5. Cupressaceae
This family was formerly divided (on the basis of leaf morphology) into:
Cupressaceae (sensu stricto)
Leaves opposite & scale-like or whorled and linear
Taxodiaceae
leaves mostly alternate
Recent study of plastid (rbcL – ribulose biphosphate carboxylase) molecular sequences has further confirmed the close relationship between the Cupressaceae “sensu stricto” and the genera formerly assigned to the Taxodiaceae

6. Cupressaceae Similarities between Cupressaceae & Taxodiaceae include:
Fusion of cone scale & bract
Lateral wings on seeds (derived from the seed coat)
≥ 2 microsporangia per microsporophyll
≥ 2 seeds per cone scale
Shedding of dwarf shoots
Non-saccate pollen with no prothallial cell development
Clustered archegonia
Peltate cone scales
DNA sequences

7. Cupressaceae Trees or shrubs
Resinous & pycnoxylic: fragrant, insecticidal, fungicidal wood
Bark fibrous and furrowed (smooth or exfoliating in plates in some Cupressus and Juniperus species)
Twigs terete, angled, or flattened. Dorsiventrally clothed by scale-like leaves or by decurrent leaf bases
Buds undifferentiated and inconspicuous (except in Sequoia, Juniperus)
Leaves simple; spirally arranged, or basally twisted to appear 2-ranked

8. leaves with twisted basal portion so they appear 2-ranked

9. Cupressaceae
Roots fibrous to woody (bearing aboveground “cypress knees" in Taxodium).
Leaves
simple, usually persisting 3-5 (≤12) years
Scale-like leaves deltate; otherwise linear, decurrent, sessile or petiolate
mature leaves appressed or spreading, often differing between lateral and leading shoots (twigs heterophyllous), sometimes strongly dimorphic on each twig
alternate and spirally arranged but sometimes twisted so as to appear 2-ranked, or opposite in 4 ranks
shed with lateral shoots
Monoecious (but dioecious in Juniperus)

12. Cupressaceae Male/pollen cones mature and shed annually,
Solitary & terminal (rarely in clusters)
simple, spherical to oblong
sporophylls overlap, bearing 2-10 abaxial microsporangia (pollen sacs)
pollen spheric & non-saccate
No prothallial cells during development

13. Cupressaceae In the female cones maturing in 1-2 seasons
shed with short shoots or persisting indefinitely on long-lived axes (shattering at maturity in Taxodium)
compound, solitary, terminal (rarely in clusters )
scales overlapping or abutting, fused to subtending bracts with only bract apex sometimes free

14. Cupressaceae Female cones: Seeds 1 – 20 per scale
The ovuliferous scale and associated bract are fused for most of their common length.
Each scale-bract complex are peltate or basally attached; flattened and woody (juicy in Juniperus) at maturity
Ovules are erect (micropyle faces away from cone axis) and they vary in number from 1 – 20 adaxially; however, may invert during maturity (e.g. Sequoia and Sequoiadendron)
Archegonia clustered and variable in number/ovule
Seeds 1 – 20 per scale
May or may not have 2-3 symmetric or asymmetric wings
Embryo with 2-15 cotyledons
During embryogenesis the zygote shows some variations.

15. Cupressaceae The zygote divides into eight free nuclei
Two tiers are formed:
a lower tier of 4 embryonal cells and
an upper tier of 4 cells that open towards the archegonial neck
The cells of the upper tier divide again into a middle / pro- suspensor tier and an upper tier giving three tiers (fig C).

16. Cupressaceae The number of cells may vary in each tier.
The prosuspensor cells elongate and push the embryonal cells out of the archegonium.
Later the primary embryonal cells divide transversely to cut off:
an upper tier of suspensor cells and
a lower tier of embryonal cells.
Later the suspensor cells start elongating (after the prosuspensor cells stop elongation) and cleavage takes place.
So cleavage polyembryony takes place.

17. Pinophyta / Coniferophyta
Pinophyta Families
Pinaceae – pines & spruces etc.
Cupressaceae – Cypress / Redwood family
Podocarpaceae – Podocarp family
Araucariaceae – Norfolk Isl. Pine family
Taxaceae – Yew family
Cephalotaxaceae
Sciadopityaceae – Umbrella-pine family

18. Podocarpaceae Second-largest conifer family, of the Pinophyta
Mainly Southern Hemisphere conifers
Consist of genera and about species of evergreen trees and shrubs.
Trunk usually straight and with more or less horizontal branches
Leaves are
lanceolate to oblong, falcate (sickle-shaped) in some species,
a distinct midrib
spirally phyllotaxy

19. Podocarpus aristulatus - branch with ovulate cones

20. Dacrydium araucarioides

21. Podocarpaceae - reproduction
Dioecious (rarely monoecious)
Pollen cones usually catkin-like
stamens numerous, close together,
2 sporangia / microsporophyll
pollen grains with 2 (0-3) saccae
The male/pollen cones are 5-20 mm long, often clustered several together

22. Podocarpaceae - reproduction
Female cones maturing in one year, much reduced to a few fleshy bracts or scales
pendant, usually borne on a thin peduncle, containing a single inverted ovule
In the female cone the ovuliferous scale is folded around the ovule to form an extra envelope called the epimatium which is either partially or completely fused with the integument.

23. Podocarpaceae - embryogeny
During embryogenesis 4 – 5 free nuclear divisions occur and gives 16 – 32 nuclei and then cell walls develop and results in the formation of two tiers.
These organize themselves into upper (15-22 celled) and embryonal (9-12 celled) tiers. No rosette tier is present.

24. Podocarpaceae - reproduction
Cells of upper tier divide  open upper tier and suspensor tiers
Embryonic cells undergo nuclear division  binucleate cells
Suspensor tier pushes embryonal tier into gametophyte
Later bi-nucleate embryonal cells divide  tetrads of cells
Cleavage polyembryony is rare; mostly simple polyembryony
The embryo has 2 cotyledons

25. Podocarpus lawrencei –
female cone

26. Seeds with red epimatium

27. Pinophyta / Coniferophyta
Pinophyta Families
Pinaceae – pines & spruces etc.
Cupressaceae – Cypress / Redwood family
Podocarpaceae – Podocarp family
Araucariaceae – Norfolk Isl. Pine family
Taxaceae – Yew family
Cephalotaxaceae
Sciadopityaceae – Umbrella-pine family

28. Family: Araucariaceae
Three genera with 40 species
Mostly restricted to S. Hemisphere
Evergreen trees, typically with a single stout trunk and very regular whorls of branches, giving them a formal appearance
Several have edible seeds similar to Pinus sp., and others produce valuable resin and amber
Dioecious or monoecious
Male cones relatively large, cylindrical
numerous microsporophylls
±12 inverted pollen sacs
pollen grains non-saccate and exine pitted
a number of prothallial cells are produced.

29. Monkey-puzzle, (Araucaria araucana)

30. Araucariaceae The female cones are
almost spherical, subglobose to ovoid
usually borne erect
maturing in two years
relatively large and milky
falling upon maturity or disintegrating on tree
scales one-seeded, without distinct bracts. The ovuliferous scale is intimately fused with the bract scale except in Araucaria.
Cotyledons 4, often fused into 2 double cotyledons
The embryogenesis in Araucariaceae differs from the other conifers.
Free nuclei divisions of the zygote takes place until there are about 32 nuclei in Araucaria and 64 nuclei in Agathis.

31. Araucariaceae
Initially all the nuclei are grouped in the center of the egg cell.
Cell walls are then laid down and the cells are arranged in a central group with 2 tiers of cells surrounded by an outer jacket on all sides.
The upper cells of the jacket (those facing the archegonial neck) elongate to form the suspensor, whereas the cells towards the chalazal end act as cap cells (see fig).

32. Araucariaceae
The upper tier of the central two tiers divides periclinally to form an upper tier of secondary suspensor cells and the lower tier of embryonal cells.
The latter divide and develop into the embryo proper that has two cotyledons.
There is no cleavage polyembryony.

33. Pinophyta / Coniferophyta
Pinophyta Families
Pinaceae – pines & spruces etc.
Cupressaceae – Cypress / Redwood family
Podocarpaceae – Podocarp family
Araucariaceae – Norfolk Isl. Pine family
Taxaceae – Yew family
Cephalotaxaceae
Sciadopityaceae – Umbrella-pine family

34. Taxaceae 5 Genera, 17 species
Small to moderately sized highly branched evergreen trees or shrubs
Usually neither resinous nor aromatic
no (or very few) resinous canals
Linear, flattened leaves with acute apex
The wood is pycnoxylic
Dioecious (rarely monoecious)
The male cones are 2-5 mm long
The female cones are highly reduced, with just one ovuliferous scale and one seed

35. Taxaceae
The Taxaceae and Cephalotaxaceae may be associated with the Podocarpaceae because of the solitary ovules associated with fleshy coverings
Taxus is the type genus of this family
Plants are mostly unisexual and rarely monecious.
Taxus is represented by 9 species. They are found in North America, Malaysia and Europe.
The wood of Taxus is very elastic and is used in making bows in archery.
Taxus brevifolia and T. canadensis are the sources of paclitaxel (taxol®) , a chemo-therapeutic drug used in breast and lung cancer

36. Taxaceae - reproduction
The microsporangia are arranged in small male / pollen cones.
Pollen cones solitary or clustered
Axillary
globose to ovoid
sporophylls bearing microsporangia (pollen sacs)
pollen ± spherical no saccae

37. Taxaceae - reproduction

38. Taxaceae - reproduction
Prothallial cells are not formed, the androspore cell acts directly as an antheridal initial
The microspore nucleus divides periclinally to produce:
The antheridal initial which divides to form a tube cell and a generative cell.
The generative cell may divide periclinally to form a spermatogenous cell
The spermatagenous cell divides ultimately into two male gametes / male cells.

39. Taxaceae - reproduction
The ovule has an aril which incompletely surrounds it
The mature aril is brightly red coloured, soft, juicy and sweet, and is eaten by birds which then disperse the hard seed undamaged in their droppings.
Taxaceae members are unique as their solitary seeds are not associated with cone scales
Why a conifer?
embryology – chemistry
wood anatomy – leaf & pollen morphology
Cone thought to be lost

40. Taxaceae - reproduction
After fertilization up to 32 free nuclei are formed by the zygote.
Then they organize themselves into 9 – 13 open upper cells and 9 – 13 suspensor cells and 6 – 14 embryonal cells (no rosette cells are present).
Polyembryony rarely occurs in this group
Seeds 1 per "cone," erect, not winged, hard seed coat

42. Young cones developing
Torreya californica
Young cones developing

43. Pinophyta / Coniferophyta
Pinophyta Families
Pinaceae – pines & spruces etc.
Cupressaceae – Cypress / Redwood family
Podocarpaceae – Podocarp family
Araucariaceae – Norfolk Isl. Pine family
Taxaceae – Yew family
Cephalotaxaceae
Sciadopityaceae – Umbrella-pine family

44. Cephalotaxaceae a small group of conifers
3 genera containing ~ 20 species
closely allied to the Taxaceae
included in that family by some botanists
highly branched small trees/shrubs
Family
 Taxaceae 
 Cephalotaxaceae 
 Cone aril 
 partly encloses seed 
 fully encloses seed 
 Cone maturation 
 6-8 months
 18-20 months
 Mature seed length 
 5-8 mm
 12-40 mm

45. Phylogeny of the Taxaceae and Cephalotaxaceae - note that both groups have evolved from within the other conifers

46. Cephalotaxaceae Shrubs or small trees
Leaves simple and usually spirally arranged
Plants are dioecious
Male cones arise in clusters of 6-8 cones in axils of short-shoot scale leaves
3-4 microsporangia borne abaxially
Pollen grain spherical; bear no saccae
No prothallial cells formed during pollen grain development

47. Cephalotaxus koreana

48. Globose pollen cones of Cephalotaxus harringtonia

49. Cephalotaxaceae
Megasporangiate cones occur singly in the axils of lowermost leaves of young branches
Appear green when young but redden at maturity
“Cones” consist of a central axis bearing 5-7 pairs of bracts
Each bract bears 2 ovules within its axil separated by reduced cone scale
Usually one or two ovules ripen in one cone

50. Cephalotaxaceae - reproduction
Zygote divides into 16 free nuclei which evenly associates  upper and embryonal tiers
Upper tier divides into open tier and prosuspensor tier
The open tier cells disorganise eventually and prosuspensor cells elongate and push the embryonal tier out of the archegonium at the expense of female gametophyte
Prosuspensors degenerate after secondary suspensor formation and embryonal cells divide  large embryonal tissue
No cleavage polyembryony

51. Female ovulate “cones”
Cephalotaxus koreana
Female ovulate “cones”
Immature
Mature

52. Pinophyta / Coniferophyta
Pinophyta Families
Pinaceae – pines & spruces etc.
Cupressaceae – Cypress / Redwood family
Podocarpaceae – Podocarp family
Araucariaceae – Norfolk Isl. Pine family
Taxaceae – Yew family
Cephalotaxaceae
Sciadopityaceae – Umbrella-pine family

53. Sciadopityaceae
The family was formerly included as a genus within Cupressaceae (Taxodiaceae), but recent genetic studies (Brunsfeld et al. 1994) have shown that it is clearly not allied with that group.