Table 2. Morphological traits and variability in the four morphological groups identified in the Tamus clade of Dioscorea, one corresponding to D. orientalis, and three to the currently recognized D. communis s.l.: Macaronesian clade DC1 (= D. edulis), trilobed leaf Eastern Mediterranean clade (DC2) (= D. cretica) and the DC3 cordate leaf clade of D. communis (= D. communis s.s.) (see Figure 1).
D. communis DC3 D. communis DC2 D. communis DC1 D. orientalis
Leaf Petiole (cm) 0.24–10.1 1.7–8.8 1.6–3.88 0.6–1.6
Shape Cordate Trilobed Cordate to sagittate Cordate
Size (mm) length × width Up to 180 × 150 Up to 70 × 70 Up to 125 × 110 Up to 56 × 48
Margin Thickened, not undulate Thickened, not undulate Thickened, slightly undulate Thickened and undulate
Consistency Chartaceous Chartaceous Thinly chartaceous Thinly coriaceous
Secondary veins Reticulated, usually not evident Reticulated, usually not evident Dark, visible but not prominent Concolorous and prominent
Male inflorescence Disposition In a fascicle, up to four flowers In a fascicle, up to four flowers In a fascicle, up to four flowers Solitary
Branching Compound Compound Compound Simple
Size (cm) Up to 35 Up to 25 Up to 12 6.7
Number of flowers 3–4 per fascicle, up to 73 per inflorescence 1–4 per fascicle, up to 50 per inflorescence 3–4 per fascicle, 65 per inflorescence 1–23
Pedicel (mm) 0.5–5.4 1.04–5.17 1.4–5.4 Sessile or subsessile
Female inflorescence Number of flowers 1–14 per inflorescence 1–6 per inflorescence 1–8 per inflorescence 1–4
Pedicel (mm) 4.7–11.3 2.5–9.3 3.8–7.3 Sessile or subsessile
Fruit Size (mm) 7–11, 6–10 7–11, 6–10 6–12, 1–8 5.5–11, 1–4
Shape Globose to ellipsoid Globose to ellipsoid Globose to ellipsoid Ellipsoid
Seed Number 1–6 1–6 1–6 1–6
Color Dark brown Dark brown Dark brown Dark brown
Pollen Apertures 2 2 2 2
Longest axis (µm) 31–36 31–36 28–36 35–40
Shorter axis (µm) 27–30 26–29 14–18 27–30
Perforation size (µm) 0.6–1.2 0.6–1.2 0.18–0.37 0.31–0.85
Perforations/µm2 0.5 0.5 3.9 1.9
Spines No No No Yes