Table 1 Morphological variation between P. sylvestris var. mongolica, P. densiflora, P. funebris and P. takahasii (from Cheng and Fu, 1978; Fu et al., 1999)
Character | Parental species | Assumed hybrid species | ||
|---|---|---|---|---|
P. sylvestris var. mongolica | P. densiflora | P. funebris | P. takahasii | |
Bark color | Yellow, brown-yellow | Orange-red, red-brown | Brown-yellow, golden yellow | Red-brown, brown-yellow |
First-year branchlets | Not white powdery | White powdery | Not white powdery | White powdery |
Winter buds | Brown or pale yellowish brown | Dark red-brown | Red-brown | Red-brown |
Number of needles | 2 | 2 | 2 | 2 |
Length of needles (cm) | 4–9 | 5–12 | 5–8 | 5–10 |
Needle diameter (mm) | 1.5–2 | 1 | 1–1.5 | 1–1.5 |
Needles twisted or not | Yes | No | No | Yes |
Number of resin canals | 6–11 | 4–6 | 4–8 | 8 |
Seed cones | Pendulous | Erect | Pendulous | Pendulous |
Cone length (cm) | 3–6 | 3–5.5 | 4–5 | 4–5 |
Cone diameter (cm) | 2–3 | 2.5–4.5 | 3–4.5 | 2–3 |
Seed and wing length (cm) | 1.1–1.5 | 1.5–2 | 2 | 1.5 |
Florescence | May–June | April | May–June | May–June |
Timber | Flexible | Brittle | – | – |
