Puccinia caricis-lactucae Jing X. Ji, Zhuang Li, Y. Li & Kakish., 2022

C1: Puccinia caricis-lactucae Jing X. Ji, Zhuang Li, Y. Li & Kakish. View in CoL sp. nov. ( Fig. 4 View FIGURE 4 )

MycoBank No: MB 838294.

Diagnosis:— This species is similar to P. sylvatica J. Schröt. in having spermogonia and aecia on Lactuca , but the teliospores are longer.

Typus:— CHINA, Jilin Province, Baishan City, Lushuihe , telia on Carex sp. , 3 September 2018, M. Kakishima & J. X. Ji, HMJAU 8902 , Holotype . CHINA, Heilongjiang Province, Wuchang City, Fenix Forest Park , sermogonia and aecia on Lactuca sp. , 22 June 2017, M. Kakishima & J. X. Ji, HMJAU 8899 , Epitype .

Etymology:— Named after host plant genera associated with different life-cycle stages.

Description:— Spermogonia amphigenous, surrounded by greenish-yellow lesions, densely grouped, yellow, subepidermal, flask-shaped, type 4 of Cummins & Hiratsuka (2003). Aecia is mostly hypophyllous, sometimes in large groups, spreading along veins, yellow, cupulate with peridia, Aecidium - type. Peridial cells firmly conjunct, cubic to polygonal, hyaline. Aeciospores catenulate, globose to subglobose, angular, 13.5–17.5 × 11.0–13.5 µm (av. 15.5 × 12.0 µm); walls hyaline, 0.5–0.7 µm (av. 0.6 µm) thick, densely verrucose with big granules. Immature uredinia rarely found. Telia hypophyllous, blackish brown, rounded to broadly elliptic, erumpent. Teliospores broadly clavate, ellipsoid, mostly rounded rarely conical and truncate at apices, weakly constricted at the septa, attenuate at the bases, 32.5–44.0 × 15.0–20.5 µm (av. 36.5 × 18.0 µm); walls chestnut-brown, 0.6–1.0 µm (av. 0.8 µm) thick at sides, 9.5– 13.5 µm (av. 11.0 µm) at apices; pedicels persistent, hyaline to pale brown, thin-walled, 18.5–28.0 µm (av. 23.0 µm) long.

Additional specimens examined from northeastern CHINA: — Jilin Province, Changchun , spermogonia, and aecia on Lactuca sp. , 5 July 2018, HMJAU 8905 View Materials , 9 June 2017, HMJAU 8908 View Materials . Heilongjiang Province, Wuchang , spermogonia and aecia on Lactuca sp. , 15 June 2019, HMJAU 8900 View Materials . Jilin Province, Baishan , spermogonia, and aecia on Prenanthes sp. , 6 July 2017, HMJAU 8943 View Materials , 8918 View Materials . Jilin Province, South of Changbai Mountain , spermogonia and aecia on Prenanthes sp. , 7 July 2017, HMJAU 8904 View Materials , 8920 View Materials . Jilin Province, Jilin, spermogonia and aecia on Prenanthes sp. , 29 June 2017, HMJAU 8909 View Materials . Heilongjiang Province, Wuchang , spermogonia and aecia on Prenanthes sp. , 22 June 2017, HMJAU 8898 View Materials , 2 July 2018, HMJAU 8907 View Materials . Jilin Province, Baishan , telia on Carex sp. , 2 September 2018, HMJAU 8906 View Materials , 8903 View Materials , 8921 View Materials , 3 September 2018, HMJAU 8901 View Materials , 8915 View Materials . Heilongjiang Province, Wuchang , telia on Carex sp. , 9 September 2017, HMJAU 8897 View Materials .

Hosts and distribution in northeastern CHINA ( Fig. 1 View FIGURE 1 ): —Spermogonia and aecia on Lactuca sp. (Asteraceae) (A, C); Prenanthes sp. (Asteraceae) (C, D). Telia on Carex sp. (D).

Note: —This species is morphologically similar to P. sylvatica producing spermogonial and aecial stages on several genera of Asteraceae including Lactuca, Seneccio and Taraxacum . However, the teliospore size of this species (32.5–44.0 × 15.0–20.5 µm) is shorter than that of P. sylvatica (33–60 × 16–18 µm) ( Ito 1950, Gäumann 1959, Wilson & Henderson 1966, Hiratsuka et al. 1992). In the phylogenetic analysis, this species is distant from P. sylvatica . Gäumann (1959) also considered that the spermogonial and aecial host of P. opizii Bubák was Lactuca , based on field observations, however teliospore size of P. opizii (38–60 × 15–23 µm) is larger than this species ( Zhuang et al. 1998). Uredinial and telial stages of this species are also morphologically similar to those of P. karelica Tranzschel , but the spermogonial and aecial host plant of P. karelica is Trientalis (Primulaceae) ( Ito 1950, Hiratsuka et al. 1992, Azbukina 2005, 2015). The aeciospores of this species have typical granules on their surface ( Fig. 4 View FIGURE 4 ) which are different from aeciospores of the autoecious species, P. tatarinovii Kom. & Tranzschel on Prenanthes ( Ji et al. 2016) , a species that is phylogenetically variable. This may be caused by abundant productions of aeciospores after fertilization on Lactuca and Prenanthes .