Rosa forrestiana Boulenger var. maculata L. Luo & Y. Y. Yang

Tang, Yu-Wei, Luo, Le, Liu, Xue-Sen, Tian, Xiao-Ling, Lyu, Pei-Feng, Yu, Chao, Zhang, Qi-Xiang & Yang, Yu-Yong, 2024, Rosa forrestiana var. maculata, a new variety of Rosa (Rosaceae) from Yunnan, China, Phytotaxa 652 (4), pp. 293-299 : 294-298

Rosa forrestiana Boulenger var. maculata L. Luo & Y. Y. Yang , var. nov. ( Figs.1–3 )

Type:— CHINA. Group 4, Yongzhi, Deqin County, Diqing Tibetan Autonomous Prefecture, Yunnan, China, elevation ca. 3360m, 28°06'08''N, 98°46'21''E, growing in the grasslands along the stream. 30 June 2021 (flowering), Y. Y. Yang, P. Li, X. Li & H. L. Fu, BJFULA071 (holotype: BJFC00107691 !).

Diagnosis:— This variety differs from R. forrestiana var. forrestiana by its purple spots at the petal base.

Description: Shrubs erect, 1–3 m tall. Branchlets glabrous, yellow-green. Prickles scattered or in pairs, yellowish, long, sharp. Leaves compound with 7–11 leaflets, 5 near inflorescence, 8.0–10.0 cm including petiole. Leaflets elliptic, suborbicular or obovate, 0.6–2.5 × 0.5–1.8 cm, papery, abaxially sparsely glandular-pubescent, light green, adaxially glabrous, green, base subrounded, apex obtuse or truncate, margin doubly serrate, occasionally uniserrate, teeth often glandular apically. Rachis and petiole sparsely glandular-pubescent and prickly. Stipules broad, mostly adnate to petiole, free parts ovate, apex acute, margin pectinately glandular. Flowers single, solitary, or 2–6 in cyme, 3–4 cm in diam, once-blooming in summer. Bracts 1–3, ovate-lanceolate, margin pectinately glandular. Pedicels 2–4 cm, glabrous or with caducous glandular trichomes.Sepals 5, ovate-lanceolate, apex acuminate, elongate with a leaflike tip, abaxially glandular, adaxially puberulous, margin entire or serrate, glandular, pubescent, erect, persistent. Petals 5, obovate, apex obtuse, emarginate or mucronate, light purple with a dark purple basal spot, fragrant. Styles free, slightly exserted, densely villous. Stigma yellow. Hips ovoid with a short neck at apex, 0.8–1.2 cm in diam, orange when mature, glabrous. 2n=2 x =14.

Phenology:— This new variety flowers from June to August and produces fruits from September to October.

Etymology:— The variety epithet ‘maculata’ refers to the purple spots at the base of the petal.

Vernacular name:— Chinese: ḰṄDZfiDzfl (zǐ bān diān biān qiáng wēi)

Additional specimen examined:— CHINA. The same locality as the holotype, 30 August 2021 (Fruiting), Y. Y. Yang, P. Li, X. Li & H. L. Fu, BJFULA072 (isotype: BJFC00107696!).

Distribution and habitat:— This variety is known to occur in only one locality in Deqin County. It grows at the edge of forests, along streams, in shrubs, elevation ca. 3000–3400 m. Related companion plants include Quercus (1753:994) spp., Betula (1753:982) spp., Ranunculus (1753:548) spp., etc.

Conservation status:— R. forrestiana var. maculata occurs in a summer pasture with no year-round residents (only occupied during summer), rarely affected by human activity. There are ca. 10 populations within a radius of about 500 meters from the holotype site, but more populations are expected to be discoved. Based on data currently available on this variety, the conservation status of this variety is suggested to be Data Deficient (DD) according to the IUCN Red List criteria ( IUCN 2022).

Discussion:— Plant specimens and living material of R. forrestiana var. forrestiana and R. forrestiana var. maculata were carefully compared, and we found that they are distinguished obviously by the spots at the base of the petals. In addition, previous descriptions of R. forrestiana var. forrestiana ( Yu 1985, Ku & Robertson 2003, Wu 2006) mentioned that it has fewer leaflets (5–7, rarely 9). Based on our field observations and examination of specimens, we consider the number of leaflets in R. forrestiana var. forrestiana mostly range from 7–11. Deqin is the holotype collection location for R. forrestiana var. maculata and R. forrestiana var. forrestiana . The distribution areas overlap. Therefore, we have confirmed through repeated investigations of geographical and phenotypic traits that these two varieties belong to the same species.

The petal spot of R. forrestiana var. maculata has exhibited consistent stability in its native habitat over the past three years. In 2021, we introduced R. forrestiana var. maculata to the Kunming South Tropical Garden (Kunming Nanguo Shanhua) Horticulture Technology Co., Ltd., 24°51'08''N, 102°58'23''E, 1850m. Under lower-altitude conditions, the vegetatively propagated individuals blossomed in 2023 and exhibited stable petal spots.

Figures

FIGURE 1. (A–H). Illustrations of Rosa forrestiana var. maculata, A. Habit, B. Flower, C. Spot pigmentation patterns, D. Floral anatomy, E. Stipule, F. Sepal, G. Leaflet, adaxial (left) and abaxial (right) surface, H. Hip. Drawn by Yu-Wei TANG.

FIGURE 2. (A–J). Photographs of Rosa forrestiana var. maculata, A–B. Habit in habitat, C. Leaf, D. Stipule, E. Prickle, F. Bud, G. Hip, H. Dismantled flowers, showing the petal spots, I–J. Flower, with different spot pigmentation patterns. (K). Flower of Rosa forrestiana var. forrestiana. Photographed by Yu-Yong YANG.

FIGURE 3. Holotype of Rosa forrestiana var. maculata.