Phylogeny reconstruction of Callitris Vent. (Cupressaceae) and its allies leads to inclusion of Actinostrobus within Callitris

We gratefully thank the following: Judy West, Chris Cargill and Judith Curnow (CANB) and Karen Wilson (NSW) for facilitating access to specimens for study; Ian Telford (NE), Chris Quinn (NSW), Daren Crayn and Mark Harrington (CNS), two anonymous referees, and the editor of the journal for helpful comments; John Hunnex (BM), Piero Cuccuini (FI), Peter van Welzen and Luc Willemse (L), Patrik Frödén (LD), Sven Landrein (K), James Solomon (MO), and Russell Barrett and Karina Knight (PERTH) for finding, preparing and sending images of types; Craig Brough and Anne Marshall (K) and Miguel Garcia (NSW) for finding and sending protologues. We also thank Dick Brummitt (K), Karen Wilson (NSW), Peter Wilson (NSW) and especially Nicholas Turland (with extensive, detailed communication; MO) for advice on nomenclatural issues (but JJB takes responsibility for the outcomes in this paper). The project was undertaken with the use of the N.C.W. Beadle Herbarium (NE) and support from the School of Environmental and Rural Science, UNE.

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1. Juvenile leaf phyllotaxy: 0, decussate; 1, in tetramerous whorls.

There is a transition period as leaf form changes (‘transition’ leaves, Venning 1979) and the phyllotaxy may vary in whorls of 3–4. Juvenile leaf phyllotaxy here refers to the phyllotaxy of those leaves appearing directly after the cotyledons and before any transition to adult form.

1. Persistence of juvenile leaves after the small seedling stage: 0, persistent; 1, non-persistent.

Scored from observations of herbarium and living specimens and from Garden (1957), de Laubenfels (1953, 1972), Venning (1979), Hill (1998), Harden and Murray (2000) and Farjon (2005). Adult leaves of Callitris are much-reduced scale leaves, decurrent for the greater part of their length with a closely appressed free triangular apex.

1. Phyllotaxy of adult leaves: 0, decussate; 1, trimerous whorls; 2, tetramerous whorls.

2. Length of adult leaves: 0, up to 4 mm; 1, 4–6 mm; 2, >6 mm.

The data were derived from measurements made on actively growing, green leaves on ultimate branchlets, at c. 10 cm along young branchlets from the tips. Older leaves, sometimes relatively long, still adhering to the larger stems, were not measured. Figures for maximum leaf lengths taken from the literature were considered in the construction of character states.

1. Pungent apex to adult leaves: 0, absent; 1, present.

2. Free part of adult leaves spreading outwards (non-appressed): 0, spreading outwards; 1, appressed.

3. Shape of dorsal surface of adult leaves: 0, acutely keeled; 1, obtusely keeled; 2, rounded to flattened.

Dorsal shape is related to distribution of stomates (Venning 1979). Rounded dorsal surfaces have stomates in cavities formed by the adjacent decurrent leaf parts. The cells at the interface of any two decurrent leaf edges bear papillae that overlap, causing the surfaces involved with gaseous exchange to be removed from direct contact with the external environment. Keeled surfaces have stomates in grooves formed by the central ridge and the raised adjoining leaf edges. The presence of a dorsal keel is clearly defined and usually consistent within a species (Venning 1979).

1. Degree of decurrence of adult leaves: 0, less than 40% of length; 1, 55–65% of length; 2, 70–85% of length.

Scored entirely from observations and measurements made for this study, as literature references were found to be often incomplete or inaccurate: e.g. male cones of C. baileyi were described as ‘ovoid’ (Hill 1998) and ‘2–3 mm long’ (Stanley and Ross 1989), but were found to be 6–7 mm long and cylindrical when fully mature.

1. Shape of mature male cones: 0, ovoid; 1, cylindrical.

It was important that only fully mature and extended cones were examined, as maturity affects size, including length and width, and thus shape.

1. Number of male cones per leaf axil: 0, always solitary; 1, usually solitary, occasionally clustered; 2, usually in clusters of 2–5, occasionally solitary.

2. Number of whorls of scales per male cone: 0, 8 or fewer; 1, 9 or more.

3. Length of male cones: 0, ≤3.5 mm; 1, >4 mm.

Scored from our own observations. Additional information about fertility of female cones and their persistence after seed release was taken from Saxton (1910, 1913a, b), Baird (1953), Garden (1957), de Laubenfels (1972), Venning (1979), Takaso and Tomlinson (1989), Hill (1998) and Farjon (2005).

1. Shape of unopened female-cones: 0, sub-globose to globose; 1, ovoid; 2, ovoid-conical to pyramidal.

2. Typical arrangement of female cones: 0, only solitary; 1, solitary or loosely clustered; 2, in tight clusters.

When clustered, two or more cones on separate peduncles arise from a single point on the branch subtended by a single branchlet.

1. Diameter of mature (open) female cones: 0, <11 mm; 1, 13–20 mm; 2, >23 mm.

2. Texture of outer surface of female cone: 0, smooth, sometimes undulating, often ‘glazed’; 1, rugose or rugulose, dull.

Rugose surfaces are generally dull, wrinkled or ridged and slightly rough. Smooth cone outer surfaces are often gently undulating and have a gloss that has been referred to as ‘egg shell lustre’ (Maiden 1907).

1. Tubercules (resin-filled pustules) on outer surface of female cone: 0, absent or with occasional tubercules; 1, always present.

2. Difference in length of alternate seed-cone scales: 0, <10% difference; 1, 20–30%; 2, 40–70%.

Cone scales of the upper, inner whorl of most species of Callitris are longer (and usually wider) than those in the lower, outer whorl, but in several species alternate scales are equal or close to equal in length (<10% difference in length), although usually of dissimilar widths.

1. Presence of concave furrow on dorsal surface of cone scales: 0, always present; 1, not always present.

Dorsal cone scale surfaces are usually rounded but are clearly concave in some taxa. Garden (1957) referred to the presence of ‘dorsal furrows’. In some cases, only the smaller scales might show some degree of dorsal concavity, but the others not so.

1. Prominence of dorsal point on cone scale: 0, absent; 1, present as a tiny unthickened sharp point; 2, present as a thickened conical projection or a large scale-like projection.

2. Relative thickness of cone scales: 0, thin; 1, thick.

The upper, smaller scales are thinner than the lower, larger scales. Thin is <3.0 mm for the latter, and <2.5 mm for the former; thick is >3.5 mm for the latter, and >3.0 mm for the former.

1. Shape of cone scale margins: 0, thin and flange-like; 1, not so.

Callitris scales have relatively thick margins that are valvate in an unopened cone; those of Actinostrobus, Diselma and Fitzroya become thinner to the edges, and in Actinostrobus tend to overlap and appear imbricate.

1. Position of cone scales at maturity: 0, widely spreading; 1, not so, remaining more or less erect.

2. Persistence of female cones after release of seed: 0, non-persistent; 1, persistent.

3. Size of columella in relation to cone size: 0, tall, reaching almost to or beyond apices of scales; 1, variable, not exceptionally short or tall; 2, very short, not extending to half the cone height.

Height in relation to cone size, in particular how far the columella tip extends in relation to the cone apex, seems more informative than actual height. In Diselma the columella is tall, generally extending a little beyond the cone scales (Doyle 1934), even though in absolute terms it is a tiny structure.

1. Structure of columella: 0, simple, 3-angled pyramid; 1, compound, 3-lobed or 3-partite.

2. Narrowing of columella at base: 0, absent; 1, present.

Scored from observations of herbarium specimens and from Saxton (1910, 1913a, b), Compton (1922), Baird (1953), Garden (1957), de Laubenfels (1972), Venning (1979), Takaso and Tomlinson (1989), Hill (1998) and Farjon (2005).

1. Fertility of cone scales: 0, not all fertile; 1, all fertile.

Cone-scale fertility is measured by the number of ovules present. The literature on some taxa is contradictory: e.g. Farjon (2005) reports that the cones of Neocallitropsis develop 1–2 ovules on each of the 4 upper (terminal) scales, and 1 on each of the 4 lower scales, but only 1–2 (–4) seeds develop in each cone (i.e. there are no sterile scales). On the other hand, however, de Laubenfels (1972) says that all 3 taxa from New Caledonia (Neocallitropsis, Callitris neocaledonica, C. sulcata) develop two ovules on each scale of the inner (upper) whorl (3 scales in Callitris and 4 in Neocallitropsis), implying that the lower scales are sterile. All the taxa produce 6 or fewer seeds. Compton (1922) also reported just eight ovules (and 1–4 seeds) for the Neocallitropsis cone. Since the observations of Compton (1922) agree with those of de Laubenfels (1972) the three New Caledonian taxa are scored as having some sterile scales within the female cone.

1. Typical number of seeds per cone: 0, 6 or less; 1, 6–15; 2, >20.

2. Relative size of seeds: 0, large, cone diameter <2.5 times maximum width of seeds; 1, small, cone diameter >3 times maximum width of seeds.

3. Number of wings on seed: 0, one; 1, two; 2, mostly 2, a few with 3; 3, mostly 3, a few with 2.

4. Equality of seed wings: 0, approximately equal; 1, markedly unequal.

5. Width of the largest wing on seed: 0, less than seed width, usually half width of seed or less; 1, at least as wide as seed.

6. Length of largest seed wing: 0, not longer than seed; 1, much longer than seed.

Appendix 4.  Morphological database
See Appendix 3 for definition of characters and state numbers; polymorphisms: 0/1 = A, 1/2 = B