Breynia pseudorostrata Huan C. Wang & Feng Yang, 2022

Yang, Feng, Li, Ping-Ping, Liu, Jin-Li, Wang, Qiu-Ping & Wang, Huan-Chong, 2022, Breynia pseudorostrata (Phyllanthaceae), a new species from Yunnan, Southwest China, Phytotaxa 539 (2), pp. 210-216 : 211-215

Breynia pseudorostrata Huan C. Wang & Feng Yang , sp. nov. ( Figs. 1 and 2 )

Diagnosis:— Morphologically, Breynia pseudorostrata is most similar to B. rostrata Merrill (1927: 346) , but clearly differs from the latter by having ovate to elliptic (ovate-lanceolate to oblong-lanceolate in B. rostrata ) leaf blades with broadly rounded to acute apex (acuminate tips in B. rostrata ), stigmas with 2 shallow and completely inflexed lobes (bifid, sharp, erect in B. rostrata ), and apex of capsules subtruncate (beaked in B. rostrata ).

Type:— CHINA. Yunnan Province: Eshan County, Shuangjiang town, Dengyun village , 24°2’25″ N, 102°10’59″ E, elev. 1015 m, 3 October 2019, H. C. Wang et al. ES8201 (holotype YUKU!, isotypes YUKU!) .

Description

Evergreen shrubs, monoecious, 0.5–2 m tall, usually completely glabrous throughout; branching phyllanthoid. Main stems and ultimate branchlets terete. Cataphylls on the main stems spiral, triangular, ca. 1 mm long. Leaves on ultimate branchlets distichous, well developed; stipules triangular-lanceolate, ca. 1 mm long, distinctly shorter than the petiole; petiole short, 2–3 mm long; leaf blades ovate to elliptic, sometimes slightly obovate, 2–5 cm long, 1.5–2.5 cm broad, papery, base obtuse to rounded, margin entire, slightly undulate when drying, apex broadly acute to rounded, adaxially green, abaxially grey or glaucous; venation pinnate, midrib elevated abaxially, lateral veins 3–6 pairs, arcuately anastomosing before margins, slightly elevated abaxially, flattened adaxially, reticulate veins obscure. Flowers axillary, usually in fascicles of staminate and pistillate flowers, sometimes solitary, staminate proximal, pistillate distal. Staminate flowers yellow-green or orange-yellow, rarely green, 2.5–4 mm in diameter; pedicels 3–10 mm long, slender, slightly broadening upwards; calyx turbinate, with 6 scales at rim of calyx tube; calyx scales imbricate, horizontally inflexed, biseriate, outer scales small, rounded, inner ones oblong; stamens 3, united into central vertical androphore, androphore ca. 1 mm long with apical anthers along it. Pistillate flowers green, pedicels 2–5 mm, not lengthening in fruit; sepals 6, connate at base, biseriate, slightly enlarged and reflexed in fruit, outer sepals small, ovate, apex acute, inner ones oblong to broadly obovate; ovary ovately cylindric, ca. 1 mm in diameter, 3-locular, ovules 2 per locule; styles ca. 2 mm, stout, erect, stigmas 3, with 2 shallow lobes, lobes almost completely inflexed. Capsules globose, tapering towards apex, 6–7 mm in diameter, with flat or slightly reflexed persistent sepals, apex with persistent stigmas; peel fleshy, tardily dehiscent; aril yellow-red or orange-red. Seeds brown, ca. 3 mm long.

Phenology:— According to our field investigations, Breynia pseudorostrata flowers and fruits from June to November.

Etymology:— The specific epithet is derived from the Greek pseudo (meaning resembling but not equaling) and the epithet of species Breynia rostrata Merrill , to which the newly named species is closely related.

Habitat and distribution:— Breynia pseudorostrata is found in Central Yunnan Province, southwest China. It usually occurs in montane slope, scrub and sunny forest margins at elevations of 300–2000 m.

Additional specimens examined (paratypes): CHINA. Yunnan: Shuangbai County, Ainishan village, elev. 1450 m, 1 October 1958, S. C. Huang 0132 (KUN); Yimen County , Luzhijiang valley , near Xiaoluzhi village , 9 August 2016, X. D. Ma et al. YM1043 (YUKU); same location, 25 September 2019, H. C. Wang et al. YM8057 (YUKU); Xinping County , elev. 1316 m, 8 August 2019, H. C. Wang et al. XP8552 (YUKU); Yuanyang County , Nansha town , valley, slope-foot, under sparse forest, 23°12’ N, 102°53’ E, elev. 300 m, 12 November 1973, D. D. Tao 1533 (KUN, HITBC); same location, 31 May 1974, Luchun team 1341 (KUN); same location, 10 October 1991, G. D. Tao 47593 (HITBC) .

Discussion

Breynia pseudorostrata is characterized by its unique style structure in genus Breynia . It shows remarkable similarities with B. rostrata , but clearly differs from the latter in its shape of leaf blade, calyx lobes of pistillate flowers, stigmas and the apex of fruit ( Fig. 3 ). The leaves of B. pseudorostrata are usually ovate to elliptic, sometimes slightly obovate, 2–5 × 1.5–2.5 cm, with broadly acute to rounded tips, its stigmas are with 2 shallow lobes, lobes are almost completely inflexed, and its apex of capsule is subtruncate. In contrast, leaves of B. rostrata are usually ovate-lanceolate to oblonglanceolate, 3–7 × 1.5–3 cm, with acuminate tips, stigmas are bifid, sharp, erect, and apex of capsule is beaked. Breynia retusa ( Dennstedt 1818: 31) Alston (1929: 204) is somewhat similar to B. pseudorostrata in leaf shape, but differs from the new species in having smaller leaves size, and sepals enlarged from 4–6 mm to ca. 12 mm in diameter in fruit, stigmas with 3 short forked arms, and apex of fruit smooth or with a shallow ring. A morphological comparison of B. pseudorostrata with its similar species is provided in Table 1 .

Figures

FIGURE 1. Breynia pseudorostrata H. C. Wang & Feng Yang. A. Habit. B. Adaxial surface of leaf. C. Pistillate flower (lateral view). D. Pistillate flower (apical view). E. Staminate flower (lateral view). F. Staminate flower (apical view). G. Fruit.

FIGURE 2. Breynia pseudorostrata Huan C. Wang & Feng Yang. A. Habit. B. Adaxial surface of leaf. C. Abaxial surface of leaf. D. Staminate flower (apical view). E. Staminate flower (lateral view). F. Pistillate flower (apical view). G. Pistillate flower (dorsal view). H. Pistillate flower (lateral view). I–K. Fruit.

FIGURE 3. Breynia pseudorostrata Huan C. Wang & Feng Yang (A–C) and B. rostrata (D–F): A, D. Adaxial surface of leaf. B, E. Pistillate flower (lateral view). C, F. Fruit. (B. pseudorostrata and B. rostrata were respectively photographed from the specimens H. C. Wang et al. XP8552 and F. A. McClure 8516 [BM000560755]).