Minuartia rossii |
Caryophyllaceae subfam. alsinoideae |
|
---|---|---|
Ross' sandwort |
|
|
Habit | Plants perennial, densely pulvinate to loosely cespitose. | Herbs, winter annual, annual, biennial, or perennial; taprooted and/or rhizomatous, rarely with tuberous thickenings (Pseudostellaria). |
Taproots | stout, woody. |
|
Stems | ascending to spreading, green or often purple, 1–3 cm, glabrous, internodes of flowering stems 0.2–1 times as long as leaves. |
prostrate to ascending or erect, simple or branched. |
Leaves | overlapping, ± tightly (vegetative), ± evenly spaced proximally (cauline), connate-perfoliate proximally, with tight, herbaceous sheath 0.2–0.3 mm; blade upwardly curved, green or often purple, keeled, prominently 1-veined abaxially, subulate, 3-angled, 1–4 × 0.5–0.7 mm, flexuous, margins rounded, herbaceous, smooth, apex green to purple, rounded, navicular, shiny, glabrous; axillary leaves well developed. |
opposite, connate proximally or not, often petiolate (basal leaves), not stipulate; blade subulate or linear to spatulate, lanceolate, or broadly ovate, seldom succulent. |
Inflorescences | solitary flowers, axillary or terminal (rarely present); bracts absent. |
terminal or axillary cymes, or flowers solitary; bracts foliaceous or reduced, herbaceous to scarious (or rarely absent); involucel bracteoles absent. |
Pedicels | 0.1–2 cm, glabrous. |
present or rarely flowers sessile. |
Flowers | hypanthium disc-shaped; sepals 1-veined, oblong-ovate (herbaceous portion usually purple, oblong-ovate), 1.5–2.5 mm, not enlarging in fruit, apex often purple, obtuse to acuminate, navicular, not hooded, glabrous; petals obovate to spatulate, 1.5–2 times as long as sepals, apex obtuse, entire. |
bisexual or seldom unisexual, sometimes inconspicuous; perianth and androecium hypogynous or perigynous, often slightly; hypanthium cup-, dish-, or disc-shaped; sepals (4–)5, distinct or seldom connate basally, sometimes hooded, not awned; petals absent or (1–)4–5, usually white, sometimes translucent, yellowish white, pink, or brownish, seldom clawed, auricles absent, coronal appendages absent, blade apex entire or 2-fid, sometimes jagged or emarginate, rarely laciniate; stamens absent or (1–)5(–10), in 1 or 2 whorls, arising from base of ovary, a nectariferous disc, or sometimes the hypanthium or hypanthium rim; staminodes absent or 1–5(–8); ovary 1- or rarely 3-locular (Wilhelmsia); styles (2–)3–5(–6), distinct; stigmas (2–)3–5(–6). |
Fruits | capsules, or rarely utricles (Scleranthus), opening by (2–)3–6, occasionally 8 or 10 valves or (3 or) 6–10 teeth; carpophore present or often absent. |
|
Capsules | on stipe ca. 0.1–0.2 mm, spheric, 1.5–2.5 mm, equaling sepals. |
|
Seeds | brown, suborbiculate, compression unknown, ca. 0.6 mm, obscurely reticulate. |
1–60+, yellowish or tan to dark red or often brown or black, usually reniform or triangular to circular and laterally compressed or ovoid to globose, rarely oblong and dorsiventrally compressed (Holosteum); embryo usually peripheral and curved, rarely central and straight (Holosteum). |
x | = 6–15, 17–19, 23. |
|
2n | = 58 (Russia), 60. |
|
Minuartia rossii |
Caryophyllaceae subfam. alsinoideae |
|
Phenology | Flowering spring–summer. | |
Habitat | Wet, turfy, gravelly, or sandy calcareous barrens, high arctic, alpine tundra, heathlands | |
Elevation | 0-500 m (0-1600 ft) | |
Distribution |
AK; NT; NU; YT; Greenland; Europe (Spitzbergen); Asia (Russian Far East) |
North-temperate regions; South America (Andean region); Europe (Mediterranean region); w Asia; c Asia (Himalayas, Mediterranean region); Africa (Mediterranean region) |
Discussion | Minuartia rossii is the northernmost member of the M. rossii complex (S. J. Wolf et al. 1979; B. Maguire 1958), a pulvinate species of moist arctic areas. While specimens occasionally have many flowers, some specimens have few if any, instead reproducing via small axillary fascicles of leaves or short shoots in the upper leaf axils (see also Ö. Nilsson 2001). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera 30, species ca. 1040 (16 genera, 137 species in the flora). Alsinoideae, often considered basal in the family and the least specialized, is in some ways the most heterogeneous of the subfamilies. Members of its largest tribe (Alsineae) share the following characteristics: stipules absent, sepals free or at most basally connate, and capsular fruits. Indehiscent fruits, relatively short hypanthia, and other floral reductions occur in varying combinations in the approximately 30 species placed in four other tribes. A broad molecular survey of Alsinoideae has revealed two major lineages and lack of support for the existing tribal circumscriptions (M. Nepokroeff et al. 2002). About three-fourths of the species are members of Arenaria, Cerastium, Minuartia, and Stellaria. Attempts have been made to move Scleranthus (fruit a utricle surrounded by an enlarged hypanthium) from Alsinoideae to either Paronychioideae (J. Hutchinson 1973, as Illecebraceae) or Scleranthaceae (A. Takhtajan 1997). Recent molecular and morphological studies by R. D. Smissen et. al. (2002, 2003) supported its retention in the Alsinoideae. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 133. | FNA vol. 5, p. 50. |
Parent taxa | Caryophyllaceae > subfam. Alsinoideae > Minuartia | Caryophyllaceae |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Arenaria rossii, Alsinanthe rossii, Alsinopsis rossii, Arenaria rossii var. apetala, M. orthotrichoides, M. rolfii, M. rossii var. orthotrichoides | |
Name authority | (R. Brown ex Richardson) Graebner: in P. F. A. Ascherson et al., Syn. Mitteleur. Fl. 5(1): 772. (1918) | Fenzl: in S. L. Endlicher, Gen. Pl. 13: 963. (1840) |
Web links |