Contributions to the morphology, synonymy, and geographical distribution of arctic plants / by Theo. Holm.

  • Holm, Theodor (Herman Theodor), 1854-1932.
Date:
1922
Catalogue details

Licence: In copyright

Credit: Contributions to the morphology, synonymy, and geographical distribution of arctic plants / by Theo. Holm. Source: Wellcome Collection.

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    POLYGONAGEAE. Polygonum viviparum L. Some tall specimens from Camden bay measure in height 16 cm. The subterranean stem is a short, but thick, horizontal rhizome with the internodes extremely short; towards the apex the rhizome is more or less bent so as to form a knee; no stolons are developed, and thin, secondary roots proceed from the rhizome. Characteristic of the species is the development of bulblets in the inflorescence; they have been described by Areschoug.^ These bulblets consist of a tuberous axis of two internodes, and the leaves are membranaceous, sheath¬ ing ; at the apex of the bulblet is a terminal bud enclosed within membranaceous leaves, mostly three. When the bulblet falls off a green leaf appears and second¬ ly roots develop from the tuberous internode. These bulblets thus form new individuals and constitute an important means for distributing the plant over a larger area since, as mentioned above, there are no stolons. P. Bistorta L. Hjalmar Nilsson ^ has described the structure of the rhizome which accord¬ ing to this author represents a monopodium with a terminal, vegetative bud, and with the flower-bearing stem developed in the axil of one of the green leaves. The rhizome resembles that of the preceding species but it is stoloniferous and, on the other hand, no bulblets are developed in the inflorescence. The speci¬ mens collected measured a height of about 18 cm., including the inflorescence with the flowers well developed. Rumex arcticus Trautv. Several specimens were collected with flowers and mature fruit; the height of a fruiting specimen from Bathurst inlet measured 40 cm., the stem being 12 cm., while the large inflorescence was 28 cm. The subterranean stem represents a very condensed pseudo-rhizome borne upon a deep, thick tap-root; iDeside that, long and quite thick secondary roots develop from the subterranean internodes. Green leaves are quite numerous, forming a rosette. Oxyria digyna (L.) Hill. In this plant the aerial shoot represents a rosette of leaves with the flower¬ bearing stems apparently lateral. With respect to the subterranean organs there is a deep but relatively slender primary root which persists for several years; from the crown of the root several erect or ascending stems are developed; they are densely covered with remnants of leaves and the internodes are very short. From these subterranean stem-portions stolons develop (Fig. E); they are covered with tubular leaves but the internodes are often quite distinct, and secondary roots proceed from the nodi. The specimen figured represents a case of the aerial shoot being developed from a stolon, beside that a young stolon of second order has developed from the ascending, subterranean stem. Most of the specimens collected were of this type, developed from stolons, and only a very few were seedlings with the primary root present. GARYOPHYLLACEAE. Lychnis [Tourn.] L. sectio Wahlbergella Fries. As a genus Wahlbergella was established by Elias Fries® and distinguished by the ovary being unicellular, the valves of the capsule bifid, and the seeds winged; the genus was placed between'Ffscana and Melandrium. 1 Bidrag till Groddknopparnas Morfologi och Biologi. Lund, 1857, p. 23. Tab. VII, fig. 16. 2 Dikotyla jordstammar. Acta Univ. Lund, xix; Lund, 1882-83. ® Botaniska Notiser. Lund l 1843, p. 143.