Tolmiea
pig-a-back-plant, piggyback plant, thousand mothers, youth-on-age
erect, leafy, 2.5–70 cm, sparsely to moderately, short to long stipitate-glandular.
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.
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.
2-beaked, (ovoid, turbinate).
brown to nearly black, subglobose, distinctly muricate.
= 7.
Tolmiea
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.)
1. Cauline leaves not or only slightly longer than wide, i.e., length-width quotient usually 0.6-1.1 (average 0.9, excluding length of basal lobes); plantlets frequently formed. | T. menziesii |
1. Cauline leaves distinctly longer than wide, i.e., length-width quotient 0.8-1.4 (average 1, excluding length of basal lobes); plantlets on leaves sporadically produced. | T. diplomenziesii |
CA
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
