T. sutchuenensis

Sun, Bin, Cui, Yi-Ming, Wang, Hai-Feng, Ferguson, David K., Xiang, Qiao-Ping, Ma, Qing-Wen & Wang, Yu-Fei, 2015, Recognizing the species of Thuja (Cupressaceae) based on their cone and foliage morphology, Phytotaxa 219 (2), pp. 101-117 : 107

T. sutchuenensis

Seed cones broadly ovate or elliptic ( Fig. 2E ), 5–8 mm × 3–4 mm. Bract-scale complexes 4–5 pairs, the second whorl obovate, apex rounded, base cuneate, umbo apex obtuse ( Fig. 2J ).

Facial leaves without glands, lateral leaves with inturned apex, no overlapping between the adjacent lateral leaves ( Fig. 2O ). Leaf apex obtuse with micro-teeth.

Stomata on both the abaxial and adaxial surfaces of facial leaves ( Figs. 4C, D ).

Subsidiary cells with low anticlinal walls, straight and continuous, margin denticulate (jagged), periclinal wall rough, the base of inner surface of papilla without thickening ( Figs. 6D , 10D , 12D ).

The inner surface of epidermal cells with low anticlinal walls, straight and continuous, margin smooth, periclinal wall rough ( Fig. 12C ).

The characters of cone morphology and foliage epidermal microstructure of the five living species of Thuja are listed in Table 2, and keys based on the characters of cone (Key 1) and foliage (Key 2) are provided.

Figures

FIGURE 2. Characters of cones, bract-scale complexes and tip branches of Thuja. A, F, K, T. koraiensis; B, G, L, T. occidentalis; C, H, M, T. plicata; D, I, N, T. standishii; E, J, O, T. sutchuenensis.—Arrows pointing to the umbo; Scale bars = 2 mm.

FIGURE 4. The distribution of stomata on the abaxial and adaxial surfaces of facial leaves and the apex of facial leaves. A–B, T. standishii; C–D, T. sutchuenensis.—DFL: abaxial facial leaves; VFL: adaxial facial leaves; Scale bars: A, C = 0.5 mm; B, D = 0.1 mm.

FIGURE 6. The arrangement of stomata and subsidiary cells on the abaxial surface of facial leaves A–B, T. standishii; C–D, T. sutchuenensis.—SC: subsidiary cell; FL: Florin ring; Scale bars: A, C = 50 μm; B, D = 10 μm.

FIGURE 10. Characters of the outer surface and inner surface of stomata on the abaxial surface of facial leaves. A–B, T. standishii; C–D, T. sutchuenensis.—FL: Florin ring; Pa: papilla; Scale bars = 20 μm.

FIGURE 12. Characters of the inner surface of epidermal cells in stomatal area and non-stomatal area on the abaxial surface of facial leaves. A–B, T. standishii; C–D, T. sutchuenensis.—IP: inner surface of papilla; Scale bars = 20 μm.