Genus Tellima in Family Saxifragaceae
In botanical taxonomy, a genus (plural genera) is a rank used to group closely related species within a family. In the hierarchy, genus sits below family and above species.
Genera are defined by shared morphological, anatomical, and genetic characteristics (for example, features of flowers, fruits, seeds, or leaves) that indicate a close evolutionary relationship among the species they contain.
Each genus can include one or more species. Examples include Rosa (roses) and Solanum (nightshades, including tomato and eggplant).
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Genus Description
Suggest a correction!Tellima (Saxifragaceae) is a small North American genus of rhizomatous herbs comprising two species that are generally accepted across North American treatments and recognized in global checklists, with a third taxon sometimes recognized (POWO, 2024; WFO, 2024; FNA, 2009). The type is Tellima grandiflora (FNA, 2009). It is distributed along the Pacific Coast and western cordillera from southeastern Alaska to northern Baja California, occurring in shaded, mesic forests, streambanks, and moist slopes at low to mid elevations (FNA, 2009; Poe-Lloyd et al., 2013). Plants form basal rosettes of long-petiolate, palmately or sometimes shallowly 3–5-lobed, cordate to truncate leaves with shallow to deep crenations and a short basal，花冠部 stipular membrane; the scapes are erect and glandular-pubescent. Inflorescences are terminal racemes; flowers are pendent, with a 5-parted hypanthium, and petaloids that are mostly white aging pink, calyculi of 1–3 bracteoles subtend each flower. Sepals are triangular to ovate; petals are fimbriate–laciniate to nearly entire, longer than the sepals; stamens are 10, opposite petals. The ovary is semi-inferior to inferior with an elongation of the receptacle; carpels are fused basally; fruit is a capsule that opens by two valves at the summit. These characters and especially the elaboration of the receptacle distinguish Tellima from close relatives (FNA, 2009; Soltis & Soltis, 1997).
Centered in western North America, Tellima reaches highest diversity in the Pacific Northwest and northern California (FNA, 2009; Poe-Lloyd et al., 2013). Typical habitats are montane to coastal forests and riparian corridors on moist, often organic-rich soils; several populations occur above 1000 m. Biogeographically the genus shows a trans-Cascadian distribution from British Columbia through the Sierra Nevada, with a boreal extension into southeastern Alaska. A distinctive, narrowly endemic element is recognized from the Columbia River gorge region as T. “Sandemanii,” treated variably at species or varietal rank (FNA, 2009).
In the Pacific Northwest, pendent, hummingbird-pollinated flowers are frequent on T. grandiflora; less is known about pollinators of other taxa (Miller, 1984). Seeds are small and may be dispersed by gravity and water; phenology tracks spring to early summer moisture. Chromosome counts are predominantly n=14 (x=14), reported across the range (FNA, 2009).
Taxonomically, Tellima has often been treated close to Heuchera, Tiarella, and Mitella; molecular work resolves it as a member of the Heuchera clade within Saxifragaceae and supports generic status (Soltis & Soltis, 1997). Some authors treat T. odorata within Heuchera (sensu latissimo), but most North American treatments recognize Tellima as distinct (Jepson, 2018; FNA, 2009). At sectional or subgeneric ranks, informal groupings have been noted around floral odor and tepal form, but recent formal schemes are limited (FNA, 2009). Alternative circumscriptions that merge Tellima into Heuchera persist and underscore current instability (Jepson, 2018).
Tellima is a locally popular ornamental shade plant; T. grandiflora is used in woodland gardens for its cascading, fragrant flower wands (Pacific Northwest Native Plant Society, 2021). No crop or timber uses are reported, and the genus is not considered invasive. The chief knowledge gaps involve regional taxonomic treatments, demographic data for narrow endemics, and pollination ecology outside the Pacific Northwest.
Poole-Lloyd et al., 2013; Flora of North America Editorial Committee, 2009; POWO, 2024; Soltis & Soltis, 1997; Jepson Flora Project, 2018; Miller, 1984.