﻿Ajaniaflavida (Asteraceae, Anthemideae), a distinct new species from southwestern China

﻿Abstract Ajaniaflavida, a new species from western Sichuan and eastern Xizang, China, is described and illustrated. It is readily assigned to A.sect.Ajania owing to its straw-colored, glossy involucres and marginally whitish scarious phyllaries. Within the section, it is distinct in being a shrub of 1−2 m in height, and in having creamy yellow florets. It is superficially similar to A.ramosa in A.sect.Phaeoscyphus, but can easily be distinguished by, among other characters, the plant height, color of the florets and margins of the phyllaries. In addition, we provide a distribution map of the new species.

During herbarium surveys of Ajania in China, seven collections, including D. E. Boufford et al. 36429 (F,PE;Fig. 1A), Kham Exped.10-0662 (PE; Fig. 1B), Y. W. Tsui 5942 (PE), and M. Z. Wen & S. C. Xiao Xiang157 (CDBI) from Sichuan, and HNWP Xizang Exped.2195 (HNWP; Fig. 1C), Kham Exped.10-1622 (PE; Fig. 1D) and Qinghai-Xizang Vegetat.Exped. 9655 (PE) from Xizang, all in China, caught our attention.Most of these collections have been previously identified as A. ramosa (C.C. Chang) C. Shih (Fig. 2), but they are quite different from that species in an array of characters.Plants of this taxon are shrubs of 1−2 m tall, with leaf blades 2-pinnatisect, involucres ca. 3 mm in diameter, and margins of the phyllaries whitish scarious, while in A. ramosa the plants are subshrubs of 40−60 cm tall, with leaf blades 1(−2)-pinnatisect, involucres 4−5 mm in diameter, and margins of the phyllaries brown scarious.To precisely determine the identity of these collections, we undertook a field visit to Jomda in eastern Xizang in September 2019.Through careful comparisons, we found that this taxon is indeed quite different from A. ramosa in A. sect.Phaeoscyphus, which is characterized by having larger (4−10 mm in diameter) capitula, not straw-colored, not glossy involucres and marginally dark brown or purple scarious phyllaries.It can be, however, readily referred to A. sect Ajania based on the smaller (ca. 3 mm in diameter) capitula, straw-colored, glossy involucres and marginally whitish scarious phyllaries.It is easily distinguishable from the remaining species within this section in being shrubs of 1−2 m tall and having creamy yellow florets.The taxon in question therefore represents a hitherto undescribed species, which we describe below.

Material and methods
For morphological comparisons, we examined physical or digitalized herbarium specimens (with high-resolution) of Ajania deposited at several major herbaria in China, including CDBI, HNWP, IBSC, KUN, NAS, PE, SZ, and WUK (acronyms follow Thiers (2024)).Specimens of A. flavida were collected and photographed during our field investigation to Xizang Autonomous Region in 2019.Morphological observations and measurements were based on fresh material as well as all herbarium specimens of this species.For conservation assessment, we used Geo CAT, the online geospatial conservation assessment tool (Bachman et al. 2011; http://geocat.kew.org/) to calculate the Extent of Occurrence (EOO) and Area of Occupancy (AOO) with a user-defined cell width of 2 km.
Etymology.The specific epithet 'flavida' refers to the creamy yellow florets of this new species.
Phenology.Flowering in September; fruiting in October.Vernacular name.川藏亚菊 (Chinese pinyin: chuān zàng yà jú).Conservation status.Ajania flavida is currently known only from eight collections made from western Sichuan (Baiyü, Batang, Dêgê) and eastern Xizang (Gonjo, Jomda), China.It usually grows on rocky slopes along roadsides in the gorges, and its habitat is at risk through human activities, such as overgrazing and road construction (Wang, pers.obs.).The Extent of Occurrence (EOO) and the Area of Occupancy (AOO) are calculated to be 7516.23 km 2 and 32 km 2 , respectively.According to the IUCN Red List Categories and Criteria (IUCN 2012(IUCN , 2022)), this species should be categorized as Vulnerable (VU): B1ab(iii)+2ab(iii).
It is noteworthy that the identity of Ajania ramosa needs to be further determined.According to our observations on both herbarium specimens and living plants in the wild, this species is poorly defined.It may encompass elements of multiple species in the genus.
Additional specimens examined (paratypes

Figure 2 .
Figure 2. Ajania ramosa in the wild (China, Shaanxi, Meixian) A habitat B habit C basal leaves (adaxial surface) D synflorescence (top view) E synflorescence (side view) F phyllaries (abaxial surface) G marginal female florets H central disk florets.Photographs by Long Wang.