Ditaxocladus kivdensis

Name

Ditaxocladus kivdensis

Rank

Species

Generic Name

[Genus] Ditaxocladus

Authors (Name)

Kodrul T. M.  

Authors (Pub.)

Krassilov V. A. Kodrul T. M. Maslova N. P.  

Publication

Plant systematics and differentiation of species over trans-Beringian land connections including a newly recognized cupressaceous conifer Ditaxocladus Guo & Sun [2010/3]

Journal

Bulletin of Geosciences

Volume

85

Issue

1

Page number

103

Year

2010

Fossil Status

leafy twigs

Stratigraphy

Paleocene

Strat. comment

Tsagayan Formation

Location

Progress locality, 18 km south-east of Raichikhinsk Town, Amur Province, Russian Federation

Paleoregion

Eurasia (Far East)

Data for Holotypus

Repository

Geological Institute, Russian Academy of Sciences, Moscow, Russian Federation

Repository Number

specimen GIN 4867 no. PK1-627 (counterpart of same specimen – GIN 4867 no. PK1-625)

Num

Figure 10A

Pub.

Plant systematics and differentiation of species over trans-Beringian land connections including a newly recognized cupressaceous conifer Ditaxocladus Guo & Sun [2010/3]

Diagnosis

Foliage branching plagiotropic, bipinnate, opposite. Branches and branchlets arising in the axils of lateral leaves, obliquely spreading. Leaves persistent, scale-like, distinctly flattened, in pseudowhorls of four, dimorphic. Facial and lateral leaves approximately equal in length. Facial leaves obovate to oblanceolate, adaxial surface flatly appressed to the shoot, length to width ratio 2 : 1 to 8 : 1; apex acuminate, rarely mucronate, thickened; apex overlaps the base of following facial leaf. Lateral leaves oblong, folded, decurrent, bilaterally flattened, clasping facial leaves or subtending branches of higher order, length to width ratio 2 : 1 to 11 : 1; apex acute or acuminate, appressed or occasionally spreading. Leaves amphistomatic, stomata in irregular rows mostly near the base and the apex of leaves. Pollen cones subglobose, up to 2.2 mm long, 2 mm in diameter, terminal on ultimate branchlets, solitary, consisting of three to four decussate pairs of microsporophylls; laminate part of microsporophylls deltoid. Sporangia abaxial, two at base of lamina, obovate, 0.3 mm long, 0.2 mm in diameter. Pollen 10–15 μm in diameter, spherical to slightly elliptical, irregularly gemmate. Seed cones pendulous, oblong, 9–11 mm long, 6.5–8 mm in diameter, borne on leafy branchlets 3–6.5mmlong, 1.5–2mmin diameter in opposite distichous pairs over fertile axes. Cone scales 6–8 in three or four decussate pairs, woody, valvate at cone base, higher peltate, shield rounded-rhomboid with small subapical, rarely nearly central, mucronate umbo and low transverse ridge.