Tolmiea |
Tolmiea menziesii |
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pig-a-back-plant, piggyback plant, thousand mothers, youth-on-age |
pig a back plant, piggy-back plant, youth-on-age |
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Habit | Herbs, rhizomatous, not stoloniferous; rhizomes sometimes branched, scaly; caudex not cormlike, with persistent leaf bases. | |||||
Flowering stems | erect, leafy, 2.5–70 cm, sparsely to moderately, short to long stipitate-glandular. |
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Leaves | in basal rosette and cauline; cauline leaves reduced distally, vegetative shoots sometimes from axillary buds of cauline leaves; stipules present; petiole stipitate-glandular, (adventitious buds usually produced at apices of petioles of rosette and cauline leaves, sometimes forming plantlets); blade ovate, shallowly 5–9-lobed, base cordate, ultimate margins strongly to obscurely, irregularly serrate to nearly dentate, each tooth ending in glandular hair, apex acute (rarely obtuse), surfaces subglabrous to stipitate-glandular; venation palmate. |
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Cauline leaves | not or only slightly longer than wide, i.e., length-width quotient usually 0.6–1.1 (average 0.9); plantlets frequently produced. |
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Inflorescences | racemes, from axillary buds in rosette, 10–150-flowered, bracteate. (Pedicels with subtending bracts.) Flowers bilaterally symmetric; hypanthium adnate to ovary only at base for less than 1 mm (ovary appearing superior), free from ovary for 4–5 mm, greenish, ± split to base, (cylindric-funnelform); sepals (persistent), 5, green with variable development of red-purple stripes, (unequal, slightly gibbous at base, stipitate-glandular, 3 dorsal sepals ovate- to elliptic-triangular, apex obtuse to rounded-mucronate, 2 ventral-lateral sepals narrowly ovate-triangular to oblong-triangular, apex acute to acuminate); petals 4, (recurved), greenish to brown-purple, (± linear); nectariferous tissue proximal to stamens; stamens 3, (inserted at apex of hypanthium opposite dorsal sepals, slightly exserted); filaments filiform; ovary superior, 1-locular, (oblong, turbinate, apex 2-cleft, stipitate-glandular), carpels connate proximally; placentation parietal; styles 2; stigmas 2. |
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Capsules | 2-beaked, (ovoid, turbinate). |
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Seeds | brown to nearly black, subglobose, distinctly muricate. |
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Basal | rosettes usually well developed. |
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x | = 7. |
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2n | = 28. |
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Tolmiea |
Tolmiea menziesii |
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Phenology | Flowering spring–summer. | |||||
Habitat | Moist woods, particularly along streams | |||||
Elevation | 0-1800 m (0-5900 ft) | |||||
Distribution |
nw North America |
AK; OR; WA; BC
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Discussion | Species 2 (2 in the flora). Although morphologically similar, as reviewed by D. E. Soltis et al. (2007), diploid and tetraploid Tolmiea each meets the criteria for all of the commonly used species concepts: they are reproductively isolated, so they are biological species; they are distinct evolutionary lineages, so the two cytotypes meet the expectations of the evolutionary species concept; each is monophyletic, so both can be considered phylogenetic (apomorphic) species; they are diagnosable on the basis of chromosome number and molecular characters, thus fitting the phylogenetic/diagnosability species concept; and morphological characters distinguish the two cytotypes (although these may be considered cryptic by some), hence they are taxonomic species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Hybrids (with 2n = 21) between Tolmiea menziesii and Tellima grandiflora have been reported from Washington (D. E. Soltis and B. A. Bohm 1985). The Cowlitz Indians applied a poultice of fresh leaves to boils and the Mahak Indians ate raw sprouts in early spring (D. E. Moerman 1998). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 8, p. 107. | FNA vol. 8, p. 108. | ||||
Parent taxa | ||||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Tiarella menziesii | |||||
Name authority | Torrey & A. Gray: Fl. N. Amer. 1: 582. 1840, name conserved , | (Pursh) Torrey & A. Gray: Fl. N. Amer. 1: 582. (1840) | ||||
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