Five new species of Cirsium (Asteraceae) from Hokkaido and Honshu, Japan are described. They all belong to Cirsium sect. Onotrophe (Cass.) DC. and are narrow endemics. Cirsium kubikialpicola Kadota (subsect. Praticola Kadota) described from Mt. Tenguhara-yama (on the border between Niigata Pref. and Nagano Pref., Honshu) is different from C. babanum Koidz. by being gynodioecious and smaller in habit, 5–6-seriate involucral phyllaries, smaller capitula and shorter florets. Cirsium rengehydrophilum Kadota (subsect. Reflexae (Kitam.) Kadota) described from the Renge-onsen spa (Niigata Pref., Honshu) is discriminated from C. myokoense Kadota by smaller habit, less branched stem with a few branches, narrower cylindrical involucres, 11–12-seriate, strongly recurved involucral phyllaries, and smaller and smooth achenes. Cirsium muramatsui Kadota (subsect. Tuberosae Kitam.) described from the Chita Peninsula (Aichi Pref., Honshu) is distinguished from C. suzukaense Kitam. by being gynodioecious with 11–12-seriate involucral phyllaries and smaller florets 15–16 mm long. Cirsium verum Kadota (subsect. Nipponocirsium Kitam. emend. Kadota) described from the campus of Tokyo Woman’s Christian University (Tokyo Pref., Honshu) is discriminated from C. yukiuenoanum Kadota by having medially pinnatilobate to coarsely serrate cauline leaves, non auriculate petiole bases, cylindrical to campanulate involucres, ascending branches and shorter achenes. Cirsium yachiyotakashimae Kadota (subsect. Borealicola Kitam. ser. Glandulosae Kadota) described from Shibetsu-cho (Nemuro Subpref., Hokkaido) is distinguished from C. boreale Kitam. by having 6–7-seriate, ascending or patent involucral phyllaries, smaller involucres and shorter florets.

The most comprehensive phylogenetic tree showing relationships among the large tropical genus Ardisia and related genera of subfamily Myrsinoideae (Primulaceae), based on nucleotide sequences of the nuclear ribosomal internal transcribed spacer (nrITS) region from 177 samples predominantly from the Neotropics, East Asia, Indo-China and Malesia is presented. Bayesian and maximum likelihood analyses showed that A. opegrapha and Labisia consecutively branched off at the basal nodes of the tree, and the remaining taxa can be divided into two major clades. Other related genera were scattered in the two clades and formed clades with members of Ardisia. Thus, Ardisia is not monophyletic as currently circumscribed. The phylogenetic tree also indicated that the traditional subgeneric circumscription only partially reflects the phylogenetic relationship within Ardisia. The results clearly suggest the need for revising the generic and subgeneric circumscription of Ardisia and its relatives.

Leaf vernation in Arisaema was surveyed extensively based on living plants and also photographs of Arisaema with unfolding leaves presented in various literatures. Two elements of vernation, the direction of terminal leaflet and the folding patterns of leaflets, were focused on. For the direction of terminal leaflet, three types, i.e., solely erect (Type 1), erect together with adjacent leaflets (Type 2), and bent downwards (Type 3), were recognized. For the folding patterns of leaflets, two types, i.e., involute (Type A) and conduplicate (Type B), were recognized. The unique vernation Type 2 of A. leschenaultii, where the terminal leaflet and adjacent lateral leaflets folded upwards together, is found for the first time in Arisaema. Conduplicate leaflet vernation Type B was found from A. kayahense for the first time in Arisaema, too. It is possibly a unique apomorphy in the Araceae that generally have involute leaves or leaflets. Arisaema kayahense is unique in Arisaema in the combination of Type 3 and Type B.

The present study deals with the identity of Linum trigynum Roxb. ex Hardw (Linaceae), a replaced synonym of Reinwardtia indica Dumort. The species contains two entities: L. trigynum sensu Roxb. and L. trigynum sensu Hardw. They are characteristically different from each other, although they were considered the same species for a long time. Based on Roxburgh’s L. trigynum, we are proposing a new subspecies of Reinwardtia indica subsp. roxburghii Sameer Patil, Sachin Sharma & S.K.Singh.

Matsumurella chinensis (Benth.) Bendiksby (Lamiaceae) is recorded for the flora of Japan for the first time. The species was found in Goto Islands, Nagasaki Pref., western Japan. Photographs of living plants, image of voucher specimen, and its distribution map are provided.

A threatened halophyte (Vulnerable (VU) category on the Japanese Red List 2020 of the Ministry of the Environment), Suaeda malacosperma H.Hara, is recorded from Shikoku Island for the first time.

Aeschynomene americana L. (Fabaceae) is reported as a new record for the Flora of Nepal. A key to the naturalized species of Aeschynomene in Nepal is also provided.

Shigezo Sugawara published “Illustrated Flora of Saghalien, vols. I–IV” in 1937–1940. After his death, his son Nobumitsu Sugawara (pen name: Kotaro Samukawa) changed the title, corrected the errors, and reprinted the books as “Flora of Saghalien, vols. I–IV” in 1975. Although the former original publication has often been cited by the latter name, both should be cited separately as “Illustrated Flora of Saghalien” (1937–40) and “Flora of Saghalien” (1975), respectively.