Ficus pongumphaii Chantaras. & Sungkaew

Chantarasuwan, B., Sungkaew, S., Pruesapan, K., Baas, P. & Welzen, P. C. van, 2019, Ficus pongumphaii (Moraceae), a new species from Thailand, compared with the ambiguous species F. talbotii, Blumea 64 (2), pp. 108-114 : 113

Ficus pongumphaii Chantaras. & Sungkaew — Fig. 3a 2, b2, c2, d2 , 4a 2, b2

Material studied. B. Chantarasuwan 180910-4; R. Pooma, K. Phattahirankanok, S. Sirimongkol, M. Poopath 3820, P. Palee 278 (see above for localities).

Surface view — Indumentum present abaxially and adaxially, consisting of glandular ellipsoid-capitate hairs with 1- or 2-celled heads, discoid-capitate glandular hairs with 4-celled heads and simple septate and non-septate hairs. Cuticle smooth. Anticlinal walls straight on both surfaces. Radiating epidermal cells around lithocysts 5–8 on both surfaces. Stomata actinocytic to anomocytic, 20–30 µm long and 17–25 µm wide; giant stomata 28–38 µm long and 25–30 µm wide.

Transverse section — Cuticle less than 2 µm thick above the lamina, above midrib 2–3 µm thick and marginally 2.5–3 µm thick. Epidermis multi-layered on both sides, cells in outer layer smaller than in the inner layer. Stomata slightly sunken, only outer cuticular ledges present. Enlarged lithocysts abundant adaxially, few abaxially. Mesophyll dorsiventral; silicified cell groups present in mesophyll and epidermis especially near the stomata of the abaxial epidermis. Palisade 2-layered. Midrib with two opposing arcs surrounded by fibre caps. Petiole with a cylinder of separate bundles, without a fibre cap (or rarely with a small fibre cap); peripheral ground tissue not sclerified. Pith bundles present in midrib and petiole. Veins vertically transcurrent; minor veins embedded in mesophyll. Marginal sclerenchyma strands absent. Druses present in mesophyll, ground tissue parenchyma and phloem parenchyma of midrib and petiole, few in the bundle sheaths around the veins; prismatic crystals absent or extremely rare in the parenchyma of midrib and petiole.

Figures

Fig. 3 Cross sections and cuticular macerations of the leaf laminas of Ficus talbotii King (left column) and Ficus pongumphaii Chantaras. & Sungkaew (right column). a1. Leaf margin without indumentum of F. talbotii; a2. leaf margin with indumentum of F. pongumphaii; b1. lamina of F. talbotii showing multi-layered epidermis on both sides and enlarged lithocysts on both surfaces; b2. lamina of F. pongumphaii showing multi-layered epidermis on both sides and enlarged lithocysts adaxially; c1. abaxial cuticular maceration of F. talbotii showing few hairs (black arrows); c2. abaxial cuticular maceration of F. pongumphaii showing many hairs; d1. petiole of F. talbotii with few hairs; d2. petiole of F. pongumphaii with an abundant hairs (a1, b1, d1: M. Nur SFN 34388, L; a2, b2, c2: R. Pooma et al. 3820, L; c1: M.F. Newman et al. 1148, L; d2: B. Chantarasuwan 180910-4, THNHM). — Photos by Bhanumas Chantarasuwan.

Fig. 2 Photos of live Ficus pongumphaii Chantaras. & Sungkaew. a. Habit in natural habitat; b–d. twigs with leaves and figs; e. fig; f. fig in longitudinal sec- tion. — Photos by Bhanumas Chantarasuwan.

Fig. 4 Free hand paradermal leaf surfaces of Ficus talbotii King (left column) and Ficus pongumphaii Chantaras. & Sungkaew (right column). a1. Abaxial paradermal leaf surface of F. talbotii showing radiating epidermal cells around lithocysts (black arrows); a2. abaxial paradermal leaf surface of F. pongumphaii showing a few radiating epidermal cells around lithocysts (black arrows) and abundant hairs; b1. adaxial paradermal leaf surface of F. talbotii showing radiating epidermal cells around lithocysts (black arrows) and no indumentum; b2. adaxial paradermal leaf surface of F. pongumphaii showing radiating epidermal cells around lithocysts (black arrows) (a1, b1: M.F. Newman et al. 1148, L; a2, b2: P. Palee 278, L). — Photos by Bhanumas Chantarasuwan.