Arenaria procera subsp. glabra, (F. N. Williams) J. Holub Arenaria longifolia, Bieb.

(b) Subsp. glabra (F. N. Williams) J. Holub View in CoL , Preslia 28: 94 (1956)

( A. graminifolia Schrader , non Ard., A. biebersteinii auct., non Schlecht., A. micradenia Smirnov ; incl. A. koriniana Fischer , A. ucrainica Sprengel ex Steudel , A. stenophylla Ledeb. , A. syreistschikowii Smirnov and A. polaris Schischkin ):

Leaf-sheaths at base of stem c. 2-5-4 mm, often purplish. Inflorescence-branches and pedicels glabrous, eglandular. Throughout the range o f the species.

This subspecies is very variable. Plants from Siberia, which possibly just reach Europe in N.E. Russia, with stems 10-15 cm, basal leaves 30-70 mm, and violet-tinged sepals have been called A. polaris Schischkin in Komarov, Fl. URSS 6: 887 (1936), and may merit subspecific rank.

5. A. longifolia Bieb. View in CoL , Fl. Taur.-Cauc. 1: 345 (1808).

Glabrous perennial with branched, slightly woody stock; stems 20-40 cm, erect, fairly stout, simple. Basal leaves 100-200xc. 0-75 mm, linear, acuminate; cauline shorter but scarcely wider. Inflorescence many-flowered, subcorymbose; pedicels usually 1-3 times as long as sepals. Sepals 2-3 mm, ovate, obtuse, with a prominent, blunt keel; petals about twice as long as sepals. C., S. & E. Russia; E. Ukraine. Rs (C, W, E).

Subgen. Porphyrantha (Fenzl) McNeill . Perennial with lanceolate leaves. Styles 3. Capsule cylindrical, long-exserted, shiny.

6. A. purpurascens Ramond ex DC. View in CoL in Lam. & DC., Fl. Fr. ed. 3,4: 785 (1805).

Perennial; stems 4-10 cm, diffuse, ascending, glabrous with distinct scale-leaves towards base; puberulent with deflexed hairs, branched and leafy in upper part. Leaves 5-10 mm, elliptic-lanceolate or lanceolate, acute, strongly 1-veined, glabrous, ciliate at base. Flowers 2-4 in rather dense clusters, rarely solitary; pedicels usually equalling sepals, pubescent, erect in fruit. Sepals 4-5-6-5 mm, lanceolate, acute, 3- to 5-veined, glabrous; petals l |- 2 times as long as sepals, oblong, palepurplish or white. Capsule 1j -2 times as long as sepals, cylindrical. Damp rocky places on mountains. • Pyrenees; Cordillera Cantàbrica. G a Hs.

Subgen. Arenaria . Annuals to perennials, of various habit; leaves less than 30 mm. Styles 3(-5). Capsule more or less ovoid.

7. A. lithops Heywood ex McNeill View in CoL , Notes Roy. Bot. Gard. Edinb. 24: 113 (1962)

( A. pulvinata Huter , non Edgew.).

Perennial, sparsely covered with very short crisped hairs, forming very compact, hard cushions 5-80 cm in diameter which show growth- rings inside; stems usually completely covered by the densely imbricate leaves. Leaves 1-1-5 mm, ovate-deltate, obtuse, recurved. Flowers 4-merous, solitary, terminal, sessile, not more than half-exserted from the cushion. Sepals c. 2-5 mm, ovatelanceolate, obtuse; petals c. 1 | times as long as sepals. Rocky mountain slopes. • S.E. Spain. Hs.

8. A. tetraquetra L. View in CoL , Sp. Pl. 423 (1753) View Cited Treatment .

Perennial, usually forming dense cushions 5-25 cm in diameter, not showing growth rings, subglabrous; stems more or less densely covered with imbricate leaves. Leaves 1-4 mm, ovate, obtuse, recurved, glabrous, ciliate at base. Flowers 4-merous or 5-merous, solitary and terminal, completely exserted from the foliage, on slightly (up to c. 1 cm) protruding stems; bracts ovate-lanceolate. Sepals 4-6 mm, lanceolate, gradually narrowed to obtuse apex, with prominent raised veins; petals slightly exceeding or up to 1 | times as long as sepals. Dry places on mountains. • C. & E. Pyrenees and mountains o f E. & S.E. Spain. G a Hs. Plants from the Pyrenees usually have 4-merous flowers. Plants from E. and S. Spain usually have 5-merous flowers and are often more densely caespitose ( var. granatensis Boiss. ).