About Ourisia sessilifolia Hook.fil.
Ourisia sessilifolia Hook.fil. are perennial herbaceous plants. They have creeping stems, with opposite leaves that are tightly packed into rosettes or subrosettes. Leaf petioles measure 3.9–29.8 mm in length. Leaf blades are 12.2–59.1 mm long by 9.7–44.5 mm wide, with a length-to-width ratio of 1.1–1.5:1. Leaves are usually ovate to very broadly ovate, widest below the middle, with a rounded apex, cuneate base, and regularly crenate edges. Both leaf surfaces are densely covered in a mix of short glandular hairs and longer non-glandular hairs; this hairiness is particularly prominent on the visible veins of the lower leaf surface. Inflorescences are erect, hairy (sometimes densely hairy) racemes that reach up to 202 mm in length, and also carry a mixture of glandular and non-glandular hairs. Each raceme holds 2–5 flowering nodes and up to a total of 10 flowers. Each flowering node produces 1–4 flowers and 2 sessile, sometimes clasping bracts that are shaped oblanceolate to narrowly obovate or narrowly elliptic. The lowest bracts are similar in appearance to the plant’s leaves, measuring 11.6–18.6 mm long and 4.4–12.2 mm wide, and bracts become smaller toward the apex of the raceme. Flowers are borne on a densely hairy pedicel up to 19.5 mm long, which usually also carries a mix of non-glandular and glandular hairs. The calyx measures 6.3–10.4 mm long, is regular in shape, and usually has all lobes equally divided all the way to the base. It is often densely hairy, with a mixture of glandular and non-glandular hairs. The corolla is 13.8–21.4 mm long, including a 4.3–9.3 mm long corolla tube. It is bilabiate and tubular-funnelform, glabrous, and white to purplish on its outer surface. The inside of the corolla is purple, with one or three lines of white hairs. Corolla lobes are 4.9–13.9 mm long, spreading, and obovate in shape. There are 4 didynamous stamens, reaching up to 9.6 mm long: two long stamens extend to the opening of the corolla tube or slightly out of it, while two short stamens remain contained inside the corolla. A short staminode 0.8–1.3 mm long is also usually present. The style measures 4.3–7.1 mm long, is exserted, and has an emarginate stigma. The ovary is 1.7–3.4 mm long and glabrous. Fruits are capsules 4.4–7.6 mm long and approximately 4.1–5.9 mm wide, that open via loculicidal dehiscence; fruit pedicels reach up to 34.0 mm long. Each capsule holds approximately 240 seeds. Seeds are 0.6–1.1 mm long by 0.4–0.6 mm wide, and have a two-layered, reticulate seed coat. Ourisia sessilifolia flowers from December to April, and fruits from December to March. Its chromosome number is 2n=48. This species, commonly known as New Zealand mountain foxglove, is endemic to the South Island and Stewart Island of New Zealand. It is found across the South Island in Western Nelson, Canterbury, Westland, Southland and Fiordland, as well as across Stewart Island. It grows in high-elevation herbfields, meadows, and grasslands located in damp, shaded habitats near rocks, cliffs, and slopes, at elevations between 800 and 2,100 m (2,600 to 6,900 ft) above sea level.
