FLORA 07 THE DISTRICT OP COLUMBIA. 45
S. SOBGHASTBTJM
I. NYMPHAEA
4. ACONITTJM L
1. Aconitum uncinatum L. Monkshood.
Low woods and thickets; infrequent. Sept. Pa. to Ga. and westward.
A form with nearly white flowers has been found by Titus Ulke.
6. ANEMONE L. Anemone.
Stem leaves not stalked; basal leaves simple, deeply lobed. Fruit pubescent with straight hairs 1. A. canadensis.
Stem leaves stalked; bacal leaves compound.
Plants 30-60 cm. high or larger, very hairy, with thick erect rootsloeks; sepals (petal-like) silky-hairy outside 2. A. virginiana.
Plants 10-20 cm. high, nearly glabrous, with very slender creeping rootstocks; sepals glabrous 3. A. quinquefolla.
1. Anemone canadensis L.
Woods below Congress Heights, May, 1893 (Steele). Widely distributed in N, Amer.
2. Anemone virginiana L,
Woods and meadows, chiefly along the upper Potomac; frequent. June-Aug.
Eastern N. Amer.
3. Anemone quinquelolia L. Wood anemone.
Woods: occasional. Apr.-May. Eastern N. Amer. {A. nemorosa of Ward's Flora.)
6. HEPATICA Mill.
1. Hepatica americana Ker. Hepatica.
Woods; common. Feb-Apr. Eastern N. Amer. (Anemone hepatica of Ward's Flora; II. hepatica and II. iriloba of American authors.)
One of the very earliest of spring flowers. Flowers bluish, pinkish, or nearly white.
The Bowers are shown in plate 25A.
7. SYNDESMON Hoffmannsegg.
1. Syndesmon thalictroides (L.) Hoffmannsegg. Hue anemone.
Woods; common. March-Apr. Eastern U. S. (Thalictrum aneinonoides Michx.;
Anemonella thalictroides Spach.)
Double-flowered plants occur occasionally.
8. TB AUT VETTERIA Fiach. & Mey.
1. Trautvetteria carolinensis (Walt.) Vail. False bugbane.
Low wet ground; Mount Vertion; Difficult Run. June-July. Southern states, north to Pa.
9. RANUNCULUS L. Buttercup.
Basal leaves, at least, moat of thorn, entire or shallowly toothed.
Upper stem loaves entire or very shallowly toothed. Plants glabrous.
Plants annual; flowers 4-6 mm. broad; fruits not beaked 1. B. pusillus.
Plants perennial, the stems root ing at the joints; flowers 12-15 mm. broad; fruits beaked 2. It. obtusiusculus.
Upper stem leaves compound or deeply lobed.
Stems glabrous; basal leaves cordate at the base; receptacle hairy.
3. B. abortivus*
8terns loosely hairy, at least, below; leaves not cordate at the base; receptacle glabrous 4. B micranthus.
Basal leaves compound or deeply lobed.
Leaves glabrous; fruits not margined. Petals about as long as the sepals.
5. B. sceleratus.
Leaves hairy, at least along the veins beneath; fruit k with an evident margin.
Beak of the fruit long, slender, and recurved; basal leaves lobed, not divided.
Petals shorter than the sepals 6. B. recurvatus.
Beak of the fruit long and straight, or very short and recurved; basal leaves usually divided to the base or composed of distinct leaflets.
Beak of the fruit long and straight. Petals much longer than the sepals.
Boots slender; plants, at least in age, producing long runners; petals broadly obovate 7. B. septentrionalis*
Roots fleshy-thickened; plants erect or nelirly so, without runners; petals oblong 8. B. hispidus.
Beak of the fruit short and recurved.
Plants wi h long runners. Petals much longer than the sepals. .9. B. repens.
Plants erect or ascending, wi hout runners.
Petals about 3 mm. long; head of fruits cyHndric, much longer than thick.
10. B. pennsylvanicus.
Petals 7-12 mm. long; head of fruits globose, about as thick as long.
Stem bulblike at the base; middle'division of the basal leaves stalked;
sepals reflexed, almost as long as the petals .11. B. bulbosus.
Stem not bulblike at the base; divisions of the basal leaves all sessile;
sepals not reflexed, much shorter than the petals 12. B. acris.
1. Ranunculus pusillus Poir.
Marshes along the Potomac and Eastern Branch. Apr .-May. Eastern U.S.
2, Ranunculus obtusiusculus Raf.
Marshes along the Eastern Branch and Hunting Creek. June-July. Kastern U. S.
(R. ambigeris S. Wat#.)
8. Banunculus abortivus L.
Woods or moist soil; common. Apr.-May. Eastern N. Amcr. (/?. rudcralia Greene.)
H. rudercdis was based upon specimens from Linden and Takoma Park. It ie a form with dull green leaves, those of the more common form being lustrous.
4. Banunculus micranthus Nutt.
Rich woods along the upper Potomac; frequent. Apr,-May. Eastern N. Amor., west to Colo. (R. abortivus micranthvs A, Gray; R. holmii Greene.)
R. kolmii waa based upon material from our region.
FLORA OF THE DISTRICT OF COLUMBIA. 159
5. Ranunculus sceleratus L.
Marshes along the Potomac and Eastern Branch; frequent. May-July. Widely distributed in temperate N. Amer.; also Eur. and Asia.
6. Ranunculus recurvatus Poir.
Damp woods and thickets; common. Apr.-May. Eastern N. Amer.
7. Ranunculus septentrionalis Poir.
Low ground along the Potomac; common. Apr .-May. Eastern N. Amer. (R.
repens nitidus and R. repens, in part, of Ward's Flora.)
8. Ranunculus hispidus Michx.
Usually in dry woods and thickets; common. Apr .-May. Eastern U. S. (R.
repens hispidus and R. repens, in part, of Ward's Flora.)
9. Ranunculus repens L.
Marshes or waste ground; occasional. Apr.-June. Widely distributed in N.
Amer., largely naturalized from Eur.
10. Ranunculus pennsylvanicus L. f.
Swamp near Aqueduct Bridge, August, 1888 {Holm). Widely distributed in tem- perate N. Amer.
11. Ranunculus bulbosus L.
Fields and waste ground; abundant. Apr.-Tune. Native of Eur.; widely natural- ized in eastern N. Amer.
12. Ranunculus acris L.
Fields and waste ground; common. May-July. Native of Eur.; widely natural- ized in N. Amer.
10. FICARIA Iluds.
1. Ficaria verna Iluds. Lesser celandine.
Shaded banks. Rock Creek Park. Apr. Native of Eur. and Asia; occasionally adventivo in the northeastern U. S. (Ranunculus Ji<xiria T,.; F. ficaria Karst.)
11. THAIICTRTTM. Meadow-rue.
Leaflets waxy-glandular beneath. Fruits not stalked; filaments slender, drooping.
1. T. revolutum.
Leaflets glabrous beneath or very finely hairy, never glandular.
Filaments club-shaped, not drooping, the apex nearly as wide as the anthers.
Fruits not stalked; leaflets mostly longer than broad, usually finely hairy beneath 2. T. polygamum.
Filaments threadlike, soon drooping.
S tem leaves on long slender stalks; plants flowering in April or early May. Leaflets glabrous, mostly as broad as long; fruits not stalked, not glaucous.
3. T. dioicum.
Stem leaves mostly sessile, sometimes on short stout stalks; plants flowering mostly from late May to July.
Fruits sessile; leaflets mostly longer than broad 4. T. dasycaipum.
Fruits short-stalked; leaflets mostly as bipad as long or broader.
6. T. caulophylloides.
1. Thalictrum revolutum DC.
Woods and low ground; common. June. Eastern U. S. (T. purpurascens ceriferum Austin.)
2. Thalictrum polygamum Muhl.
Swamps or low woods; frequent. May-July. Eastern N. Amer. (T. cornuti of Wsrd's Flora.)
3. Thalictrum dioicum L.
Moist woods or thickets along TCock Creek and the upper Potomac. Apr-May.
E?stern U. S.
4. Thalictrum dasycarptun Fiech. & Lall.
Woods and thickets; frequent. May-July. Eastern U, S. (T. purpurascens of Ward's Flora, in part.)
0. Thalictrum caulopfcylloides Small.
Low ground along the upper Potomac; common. May-June. Md. to Tenn. (T.
purpurascens of Ward's Flora.)