Rubus howii auct. non Merr. & Chun, Lu and Yang, Taiwania 25: 123. 1980; Huang and Hu, Taiwania 54(4): 294. 2009.

Previously published illustrations — Lu and Yang (1980: 123, f.2)

Climbing shrubs (Fig. 1A). Young stems with densely light-tan puberulent and sparsely reverse prickles. Leaves simple, alternate, ovate to long-ovate or tri-lobed, 4–8 × 2–5 cm, veins reticulate, base cordate, 3- or 5-nerved (Fig. 1F), the lower part usually shallowly 2- or 4-lobed, margins serrate, irregularly serrate or slightly undulate, apex acuminate, young leaves usually with purple spots at both surfaces (Fig. 1B), adaxial surfaces sparsely puberulent (Fig. 1D), abaxial surfaces white sparsely puberulent to densely tan puberulent (Fig. 1E); petioles 1–4 cm, white pubescent or densely tan puberulent, with reverse prickles. Stipules deeply and pinnately divided, 6–9 mm long, lobes linear, white or tan puberulent (Fig. 1C). Racemes 4–6 cm long (Fig. 1G), terminal or axillary, florets 3–8, pedicels ca. 1–2 cm long, densely white or tan puberulent; bracts deeply and pinnately divided, 6–8 mm long, lobes long-lanceolate; flowers 1.5 cm in diameter (Fig. 1H), calyx tube cupular, 9–10 mm long, lobes, ovate-lanceolate, 6–7 mm long, apex acuminate, both surfaces white or tan puberulent, reflexed; petals 5, ovate to elliptic, 5–7 × 4–5 mm, base claw-like, apex rounded or obtuse, both surfaces white puberulent; stamens numerous, nearly equal in length with styles; filaments 1–1.2 cm long, pubescent; pistils numerous, ovary ovoid, 2 mm long, puberulent; styles 12–13 mm long, pilose; stigma 1 mm long. Syncarps orange-red to salmon colour in maturity (Fig. 1I, J), globose, 1.5 cm in diameter.

Figure 1.  

Rubus puyumaensis J.Y. Huang, P.H. Chen & A.C. Chung. A fruiting plant in natural habitat; B young leaf; C stipule; D leaf (adaxial surface); E leaf (abaxial surface); F leaves 3-lobed on vegetative branches; G inflorescence; H flower; I infructescence; J fruits. Photographed by J. Y. Huang.

Rubus puyumaensis morphologically resembles R. howii and R. refractus. They can be distinguished by the following characteristics (Table 1). The young leaves of R. puyumaensis are often with purple spots and the other two without. There are underdeveloped lobes at the lower part of leaf in R. howii, with the other two having 2–4 well-developed lobes. The inflorescences have glandular trichomes and with florets arranged loosely in R. refractus; with the other two having no glandular trichomes and florets not loosely arranged. The length of sepal lobes: R. howii 6–8 mm, R. puyumaensis 6–7 mm, R. refractus 7–9 mm. The petal colour is light-tan in R. howii, with the other two being white. The filaments are wide, flat in R. refractus and narrow, flat in the other two; puberulent in R. puyumaensis and glabrous in the other two. The lengths of pistils compared to stamens in R. howii, R. puyumaensis and R. refractus are slightly longer, as long as and conspicuously longer, respectively.

The new specific epithet commemorates the Puyuma aborigine, a group of indigenous people mainly settled in south-eastern Taiwan and includes the type locality of Rubus puyumaensis.

Endemic to Taiwan, found in forests edge in the eastern part of the island at medium altitudes 800–1500 m.

Flowering season: March to May; fruiting season: May to July.

Rubus puyumaensis is currently known to be distributed along three forest roads in the eastern part of Taiwan, including Lijia Forest Roads, Wuluh Forest Roads and Changliang Forest Roads. Its wild population consists of fewer than 1000 individuals at the national level. Therefore, based on the IUCN Red List Categories and Criteria (IUCN 2019), the conservation status assigned to R. puyumaensis is "Nationally Vulnerable" [D1+D2].