Adoxa moschatellina L.
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Basis for Former Listing
Adoxa moschatellina has a circumpolar distribution, which means it occurs in arctic, boreal, and north temperate habitats around the world. In spite of this broad distribution, it has a reputation for being rare or uncommon throughout large portions of its range. The narrow geographical and ecological range of the occurrences of A. moschatellina in Minnesota may be a cause for concern. It appears that the mature mesic hardwood forests where this species occurs are often selectively targeted for intensive forest management in northern Minnesota. In addition to the pressures of the timber industry, mesic forests in southeastern Minnesota tend to be more vulnerable to invasion by non-native species, particularly Alliaria petiolata (garlic mustard) and Rhamnus cathartica (common buckthorn). Adoxa moschatellina was listed as a special concern species in Minnesota in 1984.
Basis for Delisting
Targeted rare plant surveys over the last 2 decades increased the known occurrences of A. moschatellina to over 100, with some populations numbering in the thousands of plants. The species is now known to be more common and widely distributed in Minnesota than was once thought, and special concern status is no longer necessary. Adoxa moschatellina was delisted in 2013.
Adoxa moschatellina is a small, delicate plant with a smooth, erect stem 5-15 cm (2.0-5.9 in.) tall. The peduncle (flowering stalk) often curves or arches (see top photo). The rhizomes and stolons are reportedly musk-scented, which gives the plant its common name. There are 1-3 basal leaves each with a long petiole and a ternately compound blade. This means that each leaf blade is divided into 3 parts and each part is again divided into 3 parts. The margins of the leaf segments have coarse serrations. The leaves that originate from the stem are divided into 3 parts, but only once rather than twice, and they tend to be smaller and on shorter petioles than the basal leaves. The inflorescence appears to arise from the base of the plant and is usually composed of 5 (2-6) flowers. The flowers are arranged as 5 sides of a cube (see top photo), and are small, yellow-green, and bowl-shaped. The calyx consists of 2-4 lobes and the corolla consists of 4-6 lobes. The fruit is a dry green drupelet (Cochrane and Salamun 1974; Holmes 2005).
The habitat of A. moschatellina in Minnesota is primarily mesic hardwood forests. These are typically mature or old-growth communities dominated by Acer saccharum (sugar maple) and Tilia americana (basswood). There may also be significant amounts of Betula papyrifera (paper birch) and Betula alleghaniensis (yellow birch). In the northern part of the state there may be conifers present, particularly Thuja occidentalis (northern white cedar) and Abies balsamea (balsam fir). Specific forest native plant communities include northern mesic hardwood (cedar) forest, northern rich mesic hardwood forest, southern mesic maple-basswood forest, southern wet-mesic hardwood forest, and southern mesic oak-basswood forest. Within these habitats, A. moschatellina seems to prefer microhabitats where leaf litter is not as deep as is typical of the communities (e.g., bases of large deciduous trees; well-decayed coarse woody debris; and tip-up mounds). In southeastern Minnesota, A. moschatellina also occurs on algific talus slopes.
Biology / Life History
Adoxa moschatellina is known to flower very early in the spring, but the foliage persists most of the summer so it is not considered a spring ephemeral. It is reportedly pollinated by a variety of day-flying and night-flying insects, none of which seem specialized for this species (Holmes 2005). Adoxa moschatellina can produce seeds through either self-pollination or cross-pollination, though cross-pollination reportedly results in greater success (Holmes 2005). The method of seed dispersal is not known, but the structure of the fruit (drupe) would seem to indicate that small animals may gather the fruit for food and disperse the seeds in the process. Vegetative reproduction does occur in this species through the growth of underground structures variously reported as rhizomes and stolons.
Conservation / Management
The conservation needs of A. moschatellina are probably no different than those of other spring-flowering plant species that occur in the same habitat. In all cases, it is important to keep the tree canopy intact. This will protect the sensitive soil from desiccation, and it will also protect the shade-adapted plant community from invasion by light-adapted species that would have a competitive advantage in a sunnier environment.
Conservation Efforts in Minnesota
Several populations of A. moschatellina are known to occur in State Parks and state Scientific and Natural Areas, though no known conservation efforts have been undertaken specifically on behalf of the species in these areas.
Cochrane, T. S., and P. J. Salamun. 1974. Preliminary reports on the flora of Wisconsin No. 64. Adoxaceae - Moschatel family. Transactions of the Wisconsin Academy of Sciences, Arts and Letters 64:247-252.
Holmes, D. S. 2005. Sexual reproduction in British populations of Adoxa moschatellina L. Watsonia 25:265-273.
Minnesota Department of Natural Resources. 2012. Statement of need and reasonableness. Minnesota Department of Natural Resources. Division of Ecological and Water Resources. St. Paul, Minnesota. 337 pp.