Nymphoides hydrophylla (Lour.) Kuntze

Tippery, N. P., Pawinski, K. C. & Jeninga, A. J., 2021, Taxonomic evaluation of Nymphoides (Menyanthaceae) in eastern Asia, Blumea 66 (3), pp. 249-262 : 260

7. Nymphoides hydrophylla (Lour.) Kuntze

Nymphoides hydrophylla (Lour.) Kuntze (1891) 429. — Menyanthes hydrophylla Lour. (1790) 105. — Villarsia hydrophylla (Lour.) Roem. & Schult. (1819) 181. — Limnanthemum hydrophyllum (Lour.) Griseb.(1838) 348. — Neotype (designated here): Vũ-VăN-CƯƠNg 1684 (neo P03025570;isoneo P03025569), Vietnam, Đồng Tháp, Sa Đéc.

Menyanthes cristata Roxb. (1799) 3. — Villarsia cristata (Roxb.) Spreng. (1824) 582. — Limnanthemum cristatum (Roxb.) Griseb. (1838) 342. — Nymphoides cristata (Roxb.) Kuntze (1891) 429. — Type: Roxburgh s.n. (holo K000832793), India.

Limnanthemum taquetii H.Lév. (1910) 285. — Type: Taquet 1519 (holo E00265597 ), South Korea, Jeju Island .

Note — Original type material for N. hydrophylla apparently no longer exists, having been destroyed after falling into disre- pair ( Merrill 1935). Two white-petaled and condensed-inflorescence Nymphoides species are well represented in the type locality of southern Vietnam (i.e., Cochinchina; Loureiro 1790): N. hydrophylla and N. indica (following modern nomenclature, e.g., Ho & Ornduff 1995; Fig. 2 ). Although the protologue provides no quantitative measurement data for N. hydrophylla ( Loureiro 1790) , two elements therein are instructive for de- termining the identity of this species. First, the description of a ‘hirsute’ corolla evokes some similarity to N. indica , but this trait also could be explained by the hairy corolla throat found in N. hydrophylla ( Fig. 1b ). Perhaps more importantly, the mention of ‘crenate’ petals apparently describes petal wings, which nota- bly are absent in N. indica . Moreover, this description excludes the laciniate petal wings of N. coreana and N. parviflora , two related species that grow in eastern Asia. Modern application of the name N. hydrophylla reflects the features described by Loureiro (1790) and is consistent with our usage here. Several morphologically similar specimens attributable to N. hydrophylla were collected by Vũ-Văn-CƯƠng in Cần ThƠ (P03025567, P03025569, P03025571), Long Xuyên (P03025568), Sa Đéc (P03025570), and Vĩnh Long (P03025572), in southern Vietnam. We have selected for the neotype a specimen with abundant flowering and fruiting material. Two specimens are known with the collection number Vũ-VăN-CƯƠNg 1684; however, the neotype and isoneotype have slightly different locality information, listing the adjacent cities of Sa Đéc and Cần ThƠ, respectively.

Figures

Fig. 2 Nymphoides distribution in eastern Asia, Malesia, and Australia. Specimens are divided by inflorescence type and otherwise separated into panels for ease of viewing. Species labels reflect preliminary identifications (see text): a–b. Species with the expanded inflorescence type; c–d. species with the condensed inflorescence type.

Fig. 1 Habit and floral variation in Nymphoides: a. N. hydrophylla, condensed inflorescence type showing flowers in an umbellate cluster associated with a single floating leaf; b. N. hydrophylla flowers, white petals with entire margins and median wings; c. N. aurantiaca flower, yellow petals with fringed margins; d. N. coreana flower, white petals with fringed margins; e. N. indica flowers, white petals with a dense covering of ciliate hairs. — Photos by: a. Aditya Gadkari; b–c. N.P. Tippery; d–e. Hiroshi Moriyama.