1. MYOSOTIS, Linn.
Annual or perennial herbs, usually move or less hispid. Leaves alternate, entire, radical petioled, cauline sessile. Flowers small, blue or white or yellow, in scorpioid simple or branched racemes, destitute of bracts, or in the axils of the upper leaves, rarely solitary and terminal. Calyx 5-lobed or -partite; lobes narrow, hardly altered in fruit. Corolla with a cylindrical tube partly closed with 5 small scales in the throat; limb spreading, 5-lobed; lobes contorted in the bud. Stamens 5, affixed to the corolla-tube, included or exserted; anthers ovate or oblong. Ovary deeply 4-lobed; style filiform. Nutlets 4, ovoid-oblong, smooth and shining, attached by a small basal area.
A well-known genus of nearly 50 species, plentiful in the temperate regions of the Northern Hemisphere and in New Zealand, rare elsewhere. One of the New Zealand species extends to Australia, the rest are endemic.
I have followed the "Genera Plantarum" and Engler and Prantl's Pflanzenfamilien in reducing Exarrhena to a section of Myosotis. Its distinguishing characters lie in the usually large campanulate corolla, the stamens inserted high up the corolla-tube between the scales, so that the anthers are altogether above the level of the scales and exserted beyond the tube, and in the filaments being usually (but not invariably) longer than the anthers. But M. albo-sericea and M. Goyeni have the corolla of Exarrhena with the stamens of Myosotis, and a variety of M. capitata has the anthers exserted beyond the tube; while the position of the stamens on the corolla-tube varies in both Myosotis and Exarrhena.
The student must bear in mind that several species greatly resemble one another in habit and foliage, although widely different in the flowers. This is specially the case with M. Forsteri, a true Myosotis, and M. petiolata, an undoubted Exarrhena. M. capitata, M. explanata, M. concinna, and M. macrantha are all very near to one another in size, habit, and foliage, and all have unlike flowers.
Section I. (Eumyosotis). Stamens inserted on the corolla-tube; filarnents shorter than the anthers, which are included in the tube, their tips not exceeding the corolla-scales.
| * Flowers solitary, sessile, terminal. Leaves small, imbricate. | |
| Small, densely tufted, 2–6 in. diam. Leaves ¼ in., linear-oblong | 1. M. uniflora. |
| Small, densely tufted, 2–4 in. diam. Leaves ⅙–¼ in., obovate-spathulate | 2. M. pulvinaris. |
| ** Flowers solitary and axillary. | |
| Small, densely tufted, 1–3 in. diam. Leaves crowded. Flowers few, large, ⅓ in. long, corolla-tube twice as long as the calyx | 3. M. Cheesemanii. |
| Prostrate or decumbent, leafy, 1–6 in. long. Leaves often distichous. Flowers minute, 110–18 in. long | 4. M. antarctica. |
| Prostrate or decumbent, leafy, 1–2 in. long. Flowers rather large, ¼–⅓ in. long. Anthers very long, narrow-linear | 5. M. decora. |
