Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge, 2022

Yooprasert, Sawita, Culham, Alastair, Tagane, Shuichiro, Yahara, Tetsukazu, Nguyen, Van Du, Nguyen, Khang Sinh & Utteridge, Timothy M. A., 2022, New species and new status of Urophyllum Wall. (Rubiaceae) from Cambodia and Viêtnam, Adansonia (3) 44 (11), pp. 91-114 : 95-98

Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge , stat. nov.

( Fig. 2A, B )

Urophyllum longifolium (Wight) Hook.f. var. annamense Pierre ex Pit. in H.Lecomte, Flore générale de l’Indo-Chine 3: 202 ( Pitard 1923).

— TYPE: Viêtnam. Bao Chiang [in Bien Hoa , Dong Nai Province], VII.1877, Pierre 1840 (♀) (lecto-, designated here, P [ P03922480 ]! ; isolecto-, BM!, C!, K!, NY photo!, P [ P03922444 , P03922481 ]!) , syn. nov.

Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge , stat. nov. is similar toU. longifolium (Wight) Hook.f. in most of the appearance but differs in its corolla colour, which is green instead of white. It also differs from U. glabrum and U. schmidtii C.B.Clarke in having stipules which are folded toward the adaxial side rather than stipules appressed to the stem but not folded. The species also differs from U. schmidtii in its compound cymose inflorescence and calyx with small teeth or nearly entire (not conspicuously lobed), instead of pedunculate umbellate inflorescences and calyx lobed, that are found in U. schmidtii .

SPECIMENS EXAMINED. — Viêtnam. Lam Dong Province, Bao Loc, piste menant à la montagne [track leading to the mountain], 16.VII.1984, Tirvengadum 1637 (♀) ( AAU!). — Khanh Hoa Province, Khanh Vinh, Khanh Phu, Hon Ba NR, trail by the road, 12°6’48.4”N, 108°58’8”E, 884 m elev., 29.V.2019, Yooprasert et al. VN 73-3 (sterile) ( BKF!, HN!) ; 12°6’43.1”N, 108°58’25.9”E, 874 m elev., 29.V.2019, Yooprasert et al. VN 74-5 (sterile) ( BKF!) .

DISTRIBUTION. — Viêtnam. Khanh Hoa Province (Hon Ba Nature Reserve), Lam Dong Province (Bao Loc) and Dong Nai Province (Bien Hoa) ( Fig. 3 ).

HABITAT. — Primary subtropical evergreen forest; elev. c. 800 m.

PHENOLOGY. — Collected in flower and young fruit from June to July.

CONSERVATION STATUS. — Vulnerable (VU) D2.To date, Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge , stat. nov. is found in southern Viêtnam from Khanh Hoa to Dong Nai Provinces recorded from four specimens. The type specimen of the species, Pierre 1840, was collected in Bao Chiang, Cochinchine where it can be traced to Bien Hoa Province from the specimen of Dialium cochinchinense Pierre , Pierre 1814 (P00330626). The type specimen was not included for evaluating the conservation status due to historic date of collection (1877) and declining forest habitat in the locality (Bien Hoa Province) visible on the Google Earth imagery, leaving three specimens collected from two locations in Bao Loc City and Hon Ba Nature Reserve (IUCN category not reported) to be reviewed. A visit to the nature reserve in 2019 showed it was in a good condition and well managed by the reserve staff. Although agriculture reached to the border of the reserve, the population of U. annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge , stat. nov. is further away from the edge. With these small number of locations found and restricted AOO (8 km 2), the species is rated as Vulnerable (VU). Further collections are recommended to provide a full assessment of species existence.

REMARKS

Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge , stat. nov. was first published as U. longifolium var. annamense by Pitard using the manuscript of Pierre in Flore Générale de l’Indo-Chine with no taxon diagnosis but five specimens were listed without indication of a type ( Pitard 1923). These specimens are Eberhardt 3867 (P03922483, P03922489), Chevalier 38709 (P03922491), Lecomte & Finet 681 (P03922485) and 713 (P03922490), Pierre 1251 (BKF!, C!, E!, K!, L[L.2970625], P[P03922472, P03922473, P03922474]) and Pierre 1840 (BM!, C!, K!, P-photo!). After observing the specimens, they can be classified into two known taxa: U. chinense subsp. chinense Merr. & Chun (Eberhardt 3867, Chevalier 38709, and Lecomte & Finet 681 and 713) and U. schmidtii (Pierre 1251) . The specimen of Pierre 1840 is different from these two taxa and shows morphological characters similar to U. longifolium . Despite the lack of diagnosis in the original description of the taxon, and that most parts of the taxon description were not specific to any one of the specimens, there were two unique elements of the description that identify the specimen of Pierre 1840 which were the axillary, cymose inflorescences, and the illustration of a flower in the publication, the original of which is attached to the specimen. Therefore, the specimen of Pierre 1840 is selected here to represent as a type specimen of the variety. The herbarium specimen deposited in P was chosen as the lectotype based upon Pierre’s biography in Taxonomic Literature Second edition ( Stafleu & Cowan 1983) showing that he went back to Paris in 1877 and worked on the manuscript there.

Populations of U. longifolium var. longifolium are recorded from Tenasserim, Myanmar through Peninsular Thailand with the most southern in Songkhla Province ( Yooprasert 2021). However, specimens assigned to U. longifolium var. annamense are found only in Viêtnam, further away and disjunct from other populations of U. longifolium . These specimens can also be distinguished by their corolla colour (green instead of white). Together, these data support the change in taxonomic status from the variety to recognition at species rank as Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge , stat. nov.

Figures

FIG. 2A. — Lectotype of Urophyllum annamense (Pierre ex. Pit.) Yooprasert, Culham & Utteridge, stat. nov. Digitised image from Muséum national d’Histoire naturelle, Paris (France), Collection: Vascular plants (P), Specimen P03922480.

FIG. 3. — Occurrences of Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge, stat. nov. (), U. brochidodromum Yooprasert, Culham & Utteridge, sp. nov. (), U. pulchristipulum Yooprasert, Culham & Utteridge, sp. nov. () and U. pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge, sp. nov. ().