Raphiocarpus Chun (1946: 273)

Nguyen, Cuong Huu, Wen, Fang, Pham, Toai Minh, Nguyen, Yen Thi, Bui, Thanh Minh, Bui, Doi The, Nguyen, Khang Sinh & Averyanov, Leonid V., 2023, The checklist of Raphiocarpus species (Gesneriaceae, Didymocarpinae) in the flora of Vietnam with the description of a new species, R. bicallosus, Phytotaxa 616 (3), pp. 223-234 : 224

Raphiocarpus Chun (1946: 273) .

Type: — R. sinicus Chun (1946: 275)

Type: — D. elongata ( Jack 1823: 37) Clarke in Candolle, A. & Candolle, C. (1883: 67, typ. cons.) .

= Didissandra C.B.Clarke sect. Chiritoides Fritsch (1894: 146) .

Type:— D. sesquifolia C.B.Clarke in Hooker (1888 t. 1797) = Raphiocarpus sesquifolius (C.B.Clarke) B.L.Burtt in Weber & Burt (1998: 174).

17 species in S China and Vietnam. In Vietnam, there are 13 species (9 endemic).

Identification key to the Raphiocarpus species in the flora of Vietnam

1. Calyx lobes are free or hardly joined near the base...........................................................................................................................2.

- Calyx lobes are distinctly joined at the base, forming a cup, funnel, or tube..................................................................................12.

2. Calyx glabrous...................................................................................................................................................................................3.

- Calyx pubescent.................................................................................................................................................................................4.

3. Peduncle much longer than 1 cm; corolla light blue to greenish, 3–4 cm long ....................................................... 1. R. annamensis

- Peduncle less than 1 cm long; corolla white with a light green or reddish tint, 1.2–1.5 mm long................................... 2. R. sinicus

4. Bract 1.5–3 cm long; corolla lobes purple to violet ............................................................................................... 3. R. begoniifolius

- Bract less than 1 cm long; corolla lobes white, yellow, or orange-red..............................................................................................5.

5. Pistil glabrous ....................................................................................................................................................................................6.

- Pistil pubescent..................................................................................................................................................................................9.

6. Prophylls present, 5–8 mm long and 4–6 mm wide; corolla yellow-orange with dark purple-brown lobes; corolla tube inside at the base of the abaxial lobe with 2 prominent elongate hairy bosses................................................................................ 4. R. bicallosus

- Distinct prophylls absent; corolla uniformly white, light pink, yellowish, or orange-red; corolla tube inside glabrous, without ornamentation....................................................................................................................................................................................7.

7. Staminode present; corolla uniformly white to pale pink, 3.8–4.5 cm long ..................................................................5. R. axillaris

- Staminode absent; corolla yellow or orange, less than 3 cm long, or longer than 6 cm ...................................................................8.

8. Peduncle 10–20 cm long; corolla 2.5–3 cm long, corolla lobes yellow; capsule 6–7 cm long.......................................... 6. R. asper

- Peduncle 1.5–4.5 cm long; corolla 6–7 cm long, corolla lobes orange red; capsule 3–5 cm long......................... 7. R. macrosiphon

9. Corolla entirely white, pink, or pale lilac; corolla tube at base of abaxial lobe with two longitudinal keel-like folds........................ ............................................................................................................................................................................... 8. R. taygiangensis

- Corolla yellow or white with violet stripes at throat; corolla tube without distinct keels or longitudinal folds .............................10.

10. Cymes 3–5-flowered; the corolla white, with violet longitudinal stripes at throat, 4–5 cm long .................................. 9. R. evrardii

- Cymes are mostly 1-flowered; the corolla yellow, sometimes with purple-brown marks, 2.8–4 cm long .....................................11.

11. Peduncle 3–5 cm long; corolla 3–4 cm long, narrowly infundibular, broadening at middle; corolla lobes yellow............................. ............................................................................................................................................................................... 10. R. tamdaoensis

- Peduncle 5–8 cm long; corolla 2.8–3.2 cm long, broadly tubular, not broadening at the middle; corolla lobes purple-brown .......... ..........................................................................................................................................................................11. R. sinovietnamicus

12. Leaves pubescent; calyx funnel-form, 1.5 cm long, calyx lobes about 5 mm long; corolla yellowish, 3.5–4.5 cm long.................... ...................................................................................................................................................................................... 12. R. petelotii

- Leaves glabrous; calyx cup-form, 0.6–0.9 cm long, calyx lobes about 3 mm long; corolla white, 2.5–3 cm long............................. ................................................................................................................................................................................. 13. R. clemensiae