Stellaria
Sp. Pl. 1: 421. 1753.
Gen. Pl. ed. 5, 193. 1754.
Plants annual, winter-annual, or perennial. Taproots usually slender, perennial taxa often rhizomatous, rooting at nodes. Stems prostrate to ascending or erect, simple or branched, terete or 4-angled. Leaves sometimes connate basally into sheath, often sessile; blade 1-veined, linear or lanceolate to ovate or deltate, succulent (S. crassifolia [gemmae], S. fontinalis, S. humifusa, and S. irrigua) or not, apex acute or obtuse. Inflorescences terminal, open cymes, rarely axillary (S. alsine, S. americana) or umbellate (S. umbellata), or terminal or axillary solitary flowers; bracts paired (1 in S. dicranoides), foliaceous, scarious and reduced, or absent. Pedicels erect, sometimes reflexed in fruit, glabrous or pubescent, not glandular. Flowers usually bisexual (S. dicranoides unisexual); perianth and androecium hypogynous or weakly perigynous; hypanthium cup or disc-shaped; sepals (4–) 5, distinct, green, occasionally purple-tinged (S. irrigua) or red proximally (S. pallida), lanceolate to ovate-triangular, 2–12 mm, herbaceous (rarely coriaceous), margins often white, scarious, apex acute, acuminate, or obtuse, not hooded; petals (1–) 5 or absent, white (sometimes translucent in S. borealis), not clawed, blade apex 2-fid usually for 2/3–4/5 its length (S. holostea occasionally laciniate); nectaries at base of filaments opposite sepals usually present, disc sometimes prominent; stamens (1–) 5 or 10 or absent, arising from nectariferous disc (prominent in S. dicranoides and S. irrigua) at ovary base; filaments distinct; staminodes absent; styles [2–] 3 (–5), capitate to clavate, 0.2–7 mm, glabrous proximally; stigmas [2–] 3 (–5), terminal or subterminal, papillate (30×). Capsules globose to conic, opening by 3 or 6, occasionally 4, 8, or 10 ascending to recurved valves; carpophore present or absent. Seeds (1–) 3–20+, yellowbrown to dark-brown, globose to ellipsoid, laterally compressed, rarely shiny, papillate or rugose, rarely smooth, marginal wing absent, appendage absent. x = 10, 11, 12, 13, 15.
Distribution
Worldwide, mainly north-temperate regions
Discussion
Species ca. 120 (29 in the flora).
I have not attempted to present an infrageneric classification for Stellaria. Although several species complexes can be identified within the genus (e.g., S. media, S. longipes, S. calycantha), there are significant problems with accepting the most recent scheme (F. Pax and K. Hoffmann 1934c). Stellaria jamesiana is now placed in Pseudostellaria and S. aquatica in Myosoton. As well, S. dicranoides and S. fontinalis probably should be placed in other genera (see comments under those species). Additional study is warranted to determine both the generic circumscription of Stellaria and species relationships within the genus.
Selected References
Lower Taxa
Key
| 1 | Mid-stem and proximal leaves distinctly petiolate, broadly lanceolate to ovate or deltate | > 2 |
| 1 | Mid-stem and proximal leaves sessile to shortly petiolate; blades elliptic, ovate, lanceolate, linear, or linear-lanceolate | > 8 |
| 2 | Leaf blade bases cordate to truncate (rarely abruptly rounded) | Stellaria cuspidata |
| 2 | Leaf blade bases round or cuneate | > 3 |
| 3 | Flowers large, usually 10 mm or more diam.; petals usually exceeding sepals | > 4 |
| 3 | Petals equaling or shorter than sepals, or absent; flowers less than 10 mm diam | > 5 |
| 4 | Sepals obtuse to acute, 3.5-6 mm | Stellaria pubera |
| 4 | Sepals acuminate, (5-)7-10(-12) mm | Stellaria corei |
| 5 | Flowers solitary in axils of mid and distal stem leaves | Stellaria obtusa |
| 5 | Flowers several in foliaceous terminal cymes | > 6 |
| 6 | Sepals 5-6.5 mm; stamens 8-10; seeds 1.1-1.7 mm; tubercles taller than broad, apex acute | Stellaria neglecta |
| 6 | Sepals usually 3-5(-6) mm; stamens 1-5(-8); seeds 0.4-1.3 mm; tubercles usually broader than tall, apex usually obtuse | > 7 |
| 7 | Stamens 3-5(-8); sepals 4.5-5(-6) mm; seeds 0.9-1.3 mm diam.; petals usually present; plants usually green | Stellaria media |
| 7 | Stamens 1-3 or absent; sepals 3-4 mm; seeds mostly 0.5-0.9 mm diam.; petals usually absent; plants usually yellowish green | Stellaria pallida |
| 8 | Inflorescences, or flowers when solitary, in axils of foliage leaves on mid or distal stem | > 9 |
| 8 | Inflorescences with most flowers terminal, either several in bracteate inflorescence or solitary on long-ascending pedicels | > 18 |
| 9 | Petals equaling or longer than sepals | > 10 |
| 9 | Petals shorter than sepals, or absent | > 13 |
| 10 | Sepals narrowly lanceolate-triangular, prominently 3-veined, margins straight | Stellaria crassifolia |
| 10 | Sepals lanceolate to ovate-lanceolate, 1- or obscurely 3-veined, margins convex | > 11 |
| 11 | Seeds prominently papillate, papillae taller than broad; sepals pubescent | Stellaria parva |
| 11 | Seeds smooth, rugose, or shallowly tuberculate, not papillate; sepals glabrous | > 12 |
| 12 | Leaf blades succulent, elliptic to elliptic-lanceolate, 4-15 × 1-5 mm | Stellaria humifusa |
| 12 | Leaf blades not succulent, linear to linear-lanceolate, 27-35 × 2-3 mm | Stellaria porsildii |
| 13 | Plants forming dense cushions, mid and distal stem internodes shorter than leaves | > 14 |
| 13 | Plants creeping to straggling or ascending, sometimes forming mats, but not forming cushions, internodes equaling or longer than leaves | > 15 |
| 14 | Stamens 5; petals present, deeply divided into 2 narrowly elliptic lobes | Stellaria irrigua |
| 14 | Stamens 10; petals absent | Stellaria dicranoides |
| 15 | Leaf blades narrowly elliptic to lanceolate, oblanceolate, or linear | > 16 |
| 15 | Leaf blades broadly elliptic to ovate | > 17 |
| 16 | Flowers solitary in distal leaf axils | Stellaria fontinalis |
| 16 | Flowers in axillary inflorescences in mid and distal leaf axils | Stellaria alsine |
| 17 | Sepals obtuse at apex with ± obscure veins; styles shorter than 0.5 mm, curled; capsules globose to broadly ovoid | Stellaria obtusa |
| 17 | Sepals acute to acuminate at apex with 3 prominent veins; styles ca. 1 mm, spreading to ascending; capsules ovoid to ovoid-ellipsoid | Stellaria crispa |
| 18 | Bracts scarious or with scarious margins | > 19 |
| 18 | Bracts or subtending leaf blades without scarious margins | > 26 |
| 19 | Capsules ca. equaling or shorter than sepals | > 20 |
| 19 | Capsules longer than sepals | > 22 |
| 20 | Plants annual | Stellaria nitens |
| 20 | Plants perennial | > 21 |
| 21 | Plants compact; stems ascending, 3-10(-20) cm; petals equaling or shorter than sepals | Stellaria alaskana |
| 21 | Plants coarse; stems straggling with erect branches, 20-60 cm; petals 1.5-2 times as long as sepals | Stellaria palustris |
| 22 | Inflorescences subumbellate; petals absent | Stellaria umbellata |
| 22 | Inflorescences cymose or flowers solitary; petals present | > 23 |
| 23 | Plants delicate, creeping, often forming mats; flowers solitary and axillary or in small, few-flowered, leafy cymes; leaf blades variable in shape, midribobscure | Stellaria crassifolia |
| 23 | Plants not with the above combination of characters; leaf blades with prominent midrib | > 24 |
| 24 | Leaf blades linear-elliptic, broadest at middle or distally; angles of stems and/or margins of leaf blades minutely papillate-scabrid (30×) | Stellaria longifolia |
| 24 | Leaf blades lanceolate to linear-lanceolate, broadest proximally; angles of stems and/or margins of leaf blades not papillate-scabrid (soft hairs of cilia may be present) | > 25 |
| 25 | Sepals narrowly triangular or lanceolate, margins straight, veins 3, forming prominent ridges; seeds coarsely rugose in concentric rings; plants coarse; stems ascending, straggling; inflorescences muchbranched, many-flowered | Stellaria graminea |
| 25 | Sepals lanceolate to ovate-lanceolate, margins convex, veins 1-3, not forming ridges; seeds shallowly tuberculate to smooth; stems erect to straggling; flowers solitary or inflorescences few-flowered | Stellaria longipes |
| 26 | Flowers 20-30 mm diam.; petals 8-14 mm, longer than sepals; leaf blades narrowly lanceolate, 4-8 cm, apex acuminate | Stellaria holostea |
| 26 | Plants not having the above combination of characters | > 27 |
| 27 | Leaves widest at or above middle | > 28 |
| 27 | Leaves widest towards base | > 31 |
| 28 | Plants glandular-puberulent; pedicels arcuate, pushing capsule into substrate; seeds 3-6, ca. 2.5 mm diam | Stellaria americana |
| 28 | Plants eglandular; other characters not as above | > 29 |
| 29 | Sepals narrowly lanceolate-triangular; plants creeping, forming mats usually shorter than 5 cm | Stellaria crassifolia |
| 29 | Sepals ovate to ovate-triangular; plants with diffusely branched or ascending flowering stems taller than 5 cm | > 30 |
| 30 | Petals 4-8 mm, conspicuous, white; sepals 3.5-6 mm | Stellaria pubera |
| 30 | Petals shorter than 3 mm, inconspicuous, white or translucent; sepals2-3(-4) mm | Stellaria borealis |
| 31 | Plants straggling to scandent; stems to 60 cm; leaf blades ovate to ovate-lanceolate, 10-45 × 4-20 mm; inflorescences terminal leafy cymes | Stellaria littoralis |
| 31 | Plants not having the above combination of characters | > 32 |
| 32 | Sepals 2-3(-4) mm; open flowers less than 5 mm diam.; petals not exceeding sepals, inconspicuous or absent | > 33 |
| 32 | Sepals 3.5 mm or longer; open flowers 5 mm or more diam.; petals equaling or exceeding sepals, conspicuous | > 34 |
| 33 | Capsules broadly ovoid to globose, to 1.5 times as long as broad; styles less than 1 mm; sepals in open flowers less than 2.5 mm, veins obscure (rarely 1) | Stellaria calycantha |
| 33 | Capsules ovoid, more than 1.5 times as long as broad; styles longer than 1 mm; sepals in open flowers more than 2.5 mm with 1-3 prominent veins | Stellaria borealis |
| 34 | Sepals 4.5-6 mm; leaf blades ovate to broadly lanceolate, coriaceous, apex spinous; capsules equaling sepals | Stellaria ruscifolia |
| 34 | Sepals 3.5-5 mm; leaf blades lanceolate to linear-lanceolate, not strongly coriaceous, apex acute to acuminate, not spinous; capsules 1.5-2 times as long as sepals | Stellaria longipes |