FLORA 07 THE DISTRICT OP COLUMBIA. 45
S. SOBGHASTBTJM
I. MOLLUGO L
1. Mollugo verticillata L. . Carpetweed.
Sandy fields or waste ground; common. July-Sept, U. S. and Mex.
51, PORTULACACEAE. Purslane Family.
Leaves all clustered at the base of the stem, the blades terete. Plants perennial;
petals rose-colored; capsule opening by 3 valves..., 1, TALINtTM, Leaves not all clustered at the base of the stem, each stem bearing 2 or numerous
leaves, the blades flat or terete.
Leaves numerous on each stem; annuals with terete or wedge-shaped leaves; petals usually yellow or red;flowers axillary; capsule opening by a lid,
2. PORTULACA, Leaves 2 on each stem; perennials with tuberous roots,the leaves nearly linear, flat; petals pink; flowers in loose terminal racemes: capsule opening by 3 valves 3. CLAYTONIA.
1. TALINtTM Adans.
1. Talinnm terettfoliuxn Pursh. Fame kloweb.
Reported by Holm from a "dry moorland beyond Silver Hill.'' Eastern U. S.
2. POBTULACA L,
1. Portulaca oleracea L, Purslane.
Common weed in cultivated ground. Flowering throughou t the summer. U.S. and tropical Amer.
The plants are often cooked as "greens."
Portulaca grandijlora Hook., with flowers 2-3 cm. wide and terete leaves, is common in cultivation, and is sometimes found as a waif in waste ground.
3. CLAYTONIA L.
1. Claytonia vlrginioa L. Spring beauty.
Moist woods; common. March-May. Eastern N. Amer, The flowers are shown in plate 17A.
52. COEEIGIOLACEAE, Whitlow-wort Family.
Leaves elliptic or oblong. Plants annual; stipules present; sepals not awned.
1. ANYCHIA.
Leaves narrowly linear.
Sepals tipped with short spinelike awns; stipules present, white and srurirn?;
plants perennial ...2.PARONYCHIA.
Sepals not awned; stipules wanting; plants annual 3. SCLER.ANTHUS.
FLORA OF THE DISTRICT OF COLUMBIA* 151
1. ANYCHIA Michx. Forked chick weed.
Plants finely hairy, rather stout, the stems with short joints, usually low and spreading;
flowers nearly sessile 1. A. polygonoides.
Plants glabrous, very slender, the stems with long joints, erect; flowers on conspicu- ous pedicels . 2. A. canadensis,
1. Anychia polygonoides Raf.
Dry hillsides; frequent. July-Sept. Eastern U. S. (A. dichotoma of some authors, not of Michaux.)
2. Anychia canadensis (L.) B. S. P.
Dry woods; frequent. July-Sept. Eastern U. S. (A. dichotoma capillacea Torr.)
2. PARONYCHIA Adans.
1. Paronychia dichotoma (L.) Nutt. Whitlow-wort.
On rocks at Little Falls and Great Falls. July-Oct. Md. to Tex.
3. SCLEBANTHTTS L.
1. Scleranthus annuus L. Knawel.
Eaabys Point, north of Old Observatory; Ammendale. May. Native of Eur.;
frequently adventive in N. Amer.
53. ALSIHACEAE. Chickweed Family.
Plants with'Bcarious stipules; leaves sometimes whorled, linear; petals sometimes pint.
Leaves opposite; petals pink; styles 3 1. TISSA.
Leaves whorled; petals white; styles 5 2. SPERGTTLA.
Plants without stipules; leaves never whorled; petals white or wanting.
Capsule usually twice as long as the calyx or longer, cylindric, slightly curved, opening at the apex by 10 minute teeth; plants usually with viscid pubescence.
Petals deeply cleft, or rarely wanting 3. CEBASTITTM.
Capsule less than twice as long as the calyx, ovoid or oblong, not curved, opening by 6 or fewer valves; plants without viscid pubescence.
Petals deeply 2-cleft 4. ALSINE.
Petals entire, or sometimes wanting.
Leaves ovate; sepals acute; styles fewer than the sepals 5. ABENABIA.
Leaves narrowly linear; sepals obtuse; styles as many as the sepals.
6. SAGINA.
1. TISSA Adans.
1. Tissa rubra (L.) Britton. Sand spurry.
Occasional in waste ground and along roadsides. Apr -July. Widely distributed in the U. S.; perhaps native in some parts of X. Amer., but largely adventive from
Eur. and Asia. (Spergularia rubra Presl; Lepigonum rubrum Fries.)
2. SPERGTTLA L.
1. Sperguia arvensis L. Spurry.
Waste ground; Washington and Ammendale. June-July. Native of Eur.; widely naturalized in N. Amer.
One of our specimens is a very viscid plant with conspicuously margined seeds, suggesting saiiva Boenn. The seeds, however, are papillose, as in 8. arvensis.
The differences between the two species do not seem very constant.
3. CERASTItTM L.
Petals more than twice as long as the sepals. Plants perennial; pedicels usually lower than the calyx: ransule about twice as long as the sepals. 1. C. velutinum.
*
152 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM.
Petals shorter than or but slightly exceeding the sepals.
Inflorescence dense, the pedicels all or nearly all much shorter than the calyx.
Plants annual; leaves elliptic to broadly oval, obtuse or rounded at the apex;
petals shorter than the calyx; capsule about twice as long as the sepals.
2. C. viscosum.
Inflorescence loose and open, at least in age, the pedicels longer than the calyx.
Pedicels several times as long as the calyx; capsule about 3 times as long as the sepals; plants annual; leaves linear-oblong, acute or acuminate; petals slightly longer than the calyx 3. C. longipedunculatum.
Pedicels twice as long as the calyx or shorter; capsule not more than twice as long as the sepals; plants perennial; leaves oblong to oval, usually obtuse;
petals about equaling the calyx 4, C. vulgatum.
1. Cerastium velutinum Raf. Chickweed.
Common in open rocky places along the Potomac. Apr -May. Northern states, south to Va. (C. oblongifoUum Torr.)
2. Cerastium viscosum L. Mouse-ear chickweed.
Common in wet meadows along the upper Potomac and occasional elsewhere.
Apr-May. Native of Eur.; widely naturalized in N. Amer.
3. Cerastium longipedunculatum Muhl. Nodding chickweed.
Moist ground, chiefly along the upper Potomac. May. Widely distributed in N.
Amer. (C. nutam Raf.)
4. Cerastium vulgatum L. Mouse-ear chickweed.
Wet meadows and waste ground about Washington; Marlboro. Apr.-May. Native of Eur.; widely naturalized in the U. S.
Cerastium semidecandrum L., an annual species with smaller leaves, was collected once by C. F. Wheeler in the Department of Agriculture grounds. A European spe- cies, sparingly naturalized from Mass. to Va.
4. ALSINE L.
Stems and leaves glabrous; leaves 1.5-8 mm. wide.
Leaves linear or nearly so, not noticeably broadest at the base; seeds smooth.
1. A. longiiolia.
Leaves lanceolate or elliptic, usually broadest below the middle; seeds rough.
2. A. graminea.
Stems and leaves more or less hairy; leaves 4—40 mm. wide.
Leaves all sessile or nearly so, obtuse or acutish; sepals sparsely hairy or glabrous;
petals longer than the calyx; stamens 10 3. A. pubera.
Leaves petioled, the lower petioles as long as the blades, the blades acute to long- acuminate; sepals densely hairy; petals shorter than the calyx; stamens 3-7.
4. A. media.
1. Alslne longifolia (Mubl.) Britton. Stitchwort.
Frequent in damp meadows. Apr.-June. Widely distributed in N. Amer ; also in Eur. and Asia. (Slellaria longi/olia Muhl.)
2. Alslne graminea (L.) Britton. Starwort.
Department of Agriculture grounds and Ammendalc. Native of Eur. and Asia;
sparingly adventive in eastern N. Amer, {Slcllnria graminea L.)
3. Alsine pubera (Michx.) Britton. Star chickweed.
Shaded rocks and woods; common. Apr.-May. X. J. to Ind. and Ga. (Stellaria pubera, Michx.)
The plant sometimes flowers in late autumn, specimens having been found in flower as late as November 10. In late summer the plants send up lon% vigorous shoote with
very large broad leaves. Tho flowers are shown in plate 3111.
FLORA OF THE DISTRICT OP COLUMBIA. 153
4, Alsine media L. Common chtckweed.
Common nearly everywhere in damp ground. Feb.-May. Native of Eur, and Asia;
naturalized nearly throughout N. Amer. (Stellaria media Cyrillo.)
The plants may be found in flower at almost any time during the winter if there are a few warm days. Stellaria neglecta Weihe (S. media procera Klett & Richter) is a form with 10 stamens and somewhat crested seeds. It has been reported from our region by Holm.
Alsine aquntica (L.) Britton, with 5 styles and large leaves, was collected along the Pennsylvania Railroad, southeast of H Street Bridge, July, 1915 (J. B. S. Norton).
Native of Eur.; sparingly adventive in N. Amer. (Stellaria aquatica Scop.)
5. ARENARIA L.
1. Arenarla serpylllfolia L. Sandwort.
Common nearly everywhere. Apr,-June. Naturalized from Eur. nearly through- out eastern N. Amer.
6. SAGINA L. Pearlwort.
Parts of the flower in 5'b; seeds orange-brown, resinous-dotted 1. S. decumbens.
Parts of the flower in 4's; seeds dark brown, not resinous-dotted.. .2. S. procnmbens.
1. Sagina decumbens (Ell.) Torr. & Gray.
About Washington; rare. May-June. Eastern U. S. (S. apetala of American authors.)
2. Sagina procnmbens X.
Ammendale (Brother Arsene); brick walk in front of Army Medical Museum (Maxon & Standley). Apr.-May. Eastern U. S.
54. SILENACEAE. Fink Family.
Calyx with twice as many ribs or nerves as teeth.
Lobes of the calyx as long as the tube or often much longer; petals much shorter than the calyx lobes, purple 1. AGROSTEMMA.
Lobes of the calyx much shorter than the tube; petals usually much longer than the calyx lobes, or rarely wanting.
Styles 3 or rarely 4 2. SILENE.
Styles 5 3. LYCHNIS.
Calyx with 5 nerves or ribs, or nerveless, or with very numerous nerves (more than twice as many as the teeth).
Plants more or less hairy, especially about the flowers; leaves linear; calyx finely many-nerved, brae ted at the base 4. DIANTHUS.
Plants perfectly glabrous; leaves much broader than linear; calyx not bracted at the base.
Calyx sharply 5-angled; pedicels usually much longer than the calyx; leaves sessile and clasping... 6. VAC C ARIA.
Calyx not angled; pedicels much shorter than the calyx; at least the lower leaves short-petioled 6. SAPONARIA.