Reevesia orbicularifolia Hsiang Hao Hsue 1977
Creators: name: Feng, Hui Zhe
name: Qin, Yun Rui
name: Huang, Yun Feng
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Malvales
Malvaceae
Reevesia
Reevesia orbicularifolia

description: Taxonomy of Reevesia orbicularifolia   
During our taxonomic study on Reevesia in China, R. orbicularifolia Hsiang Hao Hsue (1977: 81) caught our attention for its extreme similarity to R. orbicularis Tardieu (1945: 413). R. orbicularifolia was described based on collection of Q. A. Wu 10022 (KUN: Fig. 1) from Yunnan of China. In the protologue (Hsue 1977) comparison was made between R. pubescens (Masters in Hooker 1874: 364) but differs in its larger leaf blade (7–18 × 6–16 cm vs. 7–19 × 4–8(–10) cm), orbicular or rarely ovate-orbicular leaf shape (vs. elliptic-ovate, oblong-ovate, ovate-lanceolate, or elliptic), rounded or truncate base (vs. obtuse, rounded or shallowly cordate, sometimes oblique), glabrous or sparsely pubescent branchlet and petiole (vs. stellate puberulent). Although, R. orbicularifolia has been recognized by Wu (1979), Hsue (1984) and Tang et al. (2007), but in the present observation we found it more similar to R. orbicularis than to R. pubescens.   
 Reevesia orbicularis was described based on the collection by E. Poilane 29279 (Fig. 2), from Bana of Vietnam. The protologue describes orbicular to obovate leaves with truncated base, entire margin; abruptly apiculated end; lower faces and upper with short scattered deciduous stellate hairs, sometimes leaving surfaces completely hairless; basilar veins 5; the laterals 4–5 pairs, sickle-shaped, confluent towards the margin; the transverse and the apparent network below; veins loosely pubescent, lateral and rib glabrous; petiole glabrous; deciduous stipules. Inflorescence terminal, corymbose, 5 cm long, loosely hairy-stellate; calyx funnel-shaped, with 3 lobes, hairy-stellate on the outside, glabrous inside, with triangular-acuminate lobes; petals 5, white, unguiculate towards the base; hairy, especially on the outer face; stamens in the head, sessile, grouped by 3; ovary globose, hairy; sessile stigmas; fruit unknown. R. orbicularis is most similar to R. gagnepainiana Tardieu (1942: 237) due to its tri-lobed calyx, but differs chiefly in its abaxially stellate puberulent, rounded leaves. Nevertheless, R. orbicularis has been rarely recognized as distinct species, except Lê (2003).   
The examination of herbarium specimens (including type materials) of Reevesia orbicularifolia and R. orbicularis shows that the two taxa are conspecific. The leaf size of R. orbicularifolia and R. orbicularis has no significant difference (10–18 × 7–13 cm vs. 7–18 × 6–16 cm.). Both the species have orbicular or ovate-orbicular, smaller leaves, with truncated base, entire margin, abaxially with stellate puberulent, adaxially sparsely stellate puberulent, sometimes leaving surfaces completely hairless, basal veins 5, the laterals 4–5 pairs, sickle-shaped, confluent towards the margin; the transverse and the apparent network below; veins loosely pubescent; stipules deciduous; inflorescence terminal, corymbose. Therefore, R. orbicularifolia is reduced as a synonymy of R. orbicularis.
description: Published as part of Feng, Hui Zhe, Qin, Yun Rui & Huang, Yun Feng, 2022, Taxonomic studies on the genus Reevesia (Malvaceae: Helicteroideae) II: on the identity of R. orbicularifolia and a new species from southwestern Guangxi, China, pp. 197-206 in Phytotaxa 545 (2) on page 197, DOI: 10.11646/phytotaxa.545.2.8, http://zenodo.org/record/6534749