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American nailwort

Rugel's nailwort, sand squares

Habit Plants annual or biennial; taproot slender. Plants annual; taproot filiform to slender.
Stems

erect or ascending to prostrate, branched, 5–60 cm, often retrorsely pubescent on 1 side.

erect, dichotomously branched, 5–50 cm, retrorsely to spreading- pubescent throughout.

Leaves

stipules ovate-lanceolate, 1.5–7 mm, apex acuminate, fimbriate;

blade spatulate to oblanceolate or linear-oblanceolate, 3–20 × 1–4 mm, herbaceous, apex acute to obtuse or rounded, glabrous to scaberulous.

stipules ovate-lanceolate, 2–6 mm, apex acuminate, entire;

blade linear to linear-oblanceolate or linear-oblong, 3–25 × 1–2.3 mm, herbaceous, apex ± acute, moderately antrorsely puberulent.

Flowers

5-merous, ± short-cylindric, with slightly enlarged hypanthium and calyx widening somewhat distally, 1–1.8 mm, sparsely to moderately pubescent proximally with hooked to straight hairs;

sepals red-brown (sometimes finely striped or mottled), white distally, midrib obscure, obovate, 0.4–0.8 mm, leathery to rigid, margins white, 0.03–0.1 mm wide, thinly herbaceous, apex broadly rounded, hood broadly rounded, awn or mucro usually absent or minute;

staminodes narrowly triangular, 0.3–0.4 mm;

style 1, cleft in distal 1/6, 0.6–0.8 mm.

5-merous, cylindric to narrowly lanceolate, with enlarged hypanthium and calyx cylindric to tapering distally, 2.3–3.5 mm, pubescent mostly proximal with hooked or usually straight hairs, sometimes with scattered straight hairs distally;

sepals flecked or solid red-brown, white distally, midrib obscure, linear-lanceolate, 1.5–2 mm, papery, margins white, 0.1–0.2 mm wide, papery, apex terminated by mucro, hood obscure, narrowly rounded, mucro short-conic, ca. 0.1 mm, glabrous;

staminodes filiform, widening proximally, 0.5–0.6 mm;

style 1, cleft in distal 1/10.

Cymes

terminal, 9–25-flowered, ± compact, forming spheroid glomerules 2–6 mm wide.

terminal and lateral, 15–50+-flowered, often forming large, congested clusters 5–30 mm wide.

Utricles

ovoid to ellipsoid, 0.6–0.8 mm, smooth, glabrous.

broadly ellipsoid to ± globose, 0.5–0.7 mm, smooth, glabrous.

Paronychia americana

Paronychia rugelii

Phenology Flowering year round. Flowering late spring–fall.
Habitat Dunes, pine/oak woodland, fields, clearings, roadsides Woodlands, fields, clearings, roadsides, waste places
Elevation 0-300 m (0-1000 ft) 0-200 m (0-700 ft)
Distribution
from FNA
AL; FL; GA; SC
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; GA
[WildflowerSearch map]
[BONAP county map]
Discussion

Plants of Paronychia americana with fewer flowers in lax cymes from Florida and Georgia were named subsp. pauciflora, a distinction that we do not feel is worth recognition.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Of conservation concern.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 5, p. 33. FNA vol. 5, p. 41.
Parent taxa Caryophyllaceae > subfam. Paronychioideae > Paronychia Caryophyllaceae > subfam. Paronychioideae > Paronychia
Sibling taxa
P. ahartii, P. argyrocoma, P. baldwinii, P. canadensis, P. chartacea, P. congesta, P. depressa, P. drummondii, P. echinulata, P. erecta, P. fastigiata, P. franciscana, P. herniarioides, P. jamesii, P. jonesii, P. lindheimeri, P. maccartii, P. monticola, P. patula, P. pulvinata, P. rugelii, P. sessiliflora, P. setacea, P. virginica, P. wilkinsonii
P. ahartii, P. americana, P. argyrocoma, P. baldwinii, P. canadensis, P. chartacea, P. congesta, P. depressa, P. drummondii, P. echinulata, P. erecta, P. fastigiata, P. franciscana, P. herniarioides, P. jamesii, P. jonesii, P. lindheimeri, P. maccartii, P. monticola, P. patula, P. pulvinata, P. sessiliflora, P. setacea, P. virginica, P. wilkinsonii
Synonyms Herniaria americana, P. americana subsp. pauciflora, Siphonychia americana, Siphonychia pauciflora Siphonychia rugelii, Gibbesia rugelii, Odontonychia interior, P. rugelii var. interior, Siphonychia interior
Name authority (Nuttall) Fenzl ex Walpers: Repert. Bot. Syst. 1: 262. (1842) (Chapman) Shuttleworth ex Chapman: Fl. South. U.S. ed. 3, 397. (1897)
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