1422 



POTENTILLA 



POTHOS 



7. grandiflora.Linn. Stem leafy, 10-20 in. high, erect, 

 branched, villous: caudex nearly simple: Ivs. with 

 appressed-hairy petioles exceeding the broadly obovate- 

 cuneiform, dentate, 1-1% -hi. long Ifts., which are green 

 and pilose-silky on both sides: fls. numerous, %-% in. 

 in diam. ; petals broad, emarginate, much exceeding the 

 acute sepals; akenes glabrous, rugulose: receptacle 

 hairy. June, July. Eu., North Asia. A good border 

 plant. Differs from the next in the smaller, broader 

 leaflets, green beneath, and the rugulose carpels. 



8. argyrophylla, Wall. (P. insignis, Royle). Tall and 

 leafy, 2-3 ft. high, stout, silky-hairy or pubescent: Ivs. 

 large, long-petioled; Ifts. 2-3 in. long, elliptic-ovate or 

 obovate, acutely toothed, white beneath, silky-hairy, 

 rarely glabrous above: fls. yellow, %-!% in. broad, 

 long, slender -pedicelled; sepals acuminate; petals 

 large, obcordate, exceeding the calyx- akenes smooth; 

 style sub-terminal, receptacle villous. June, July. 

 Himalayas. Var. atrosanguinea, Hooker (P. atrosan- 

 guinea, Lodd.). Fls. red or purple, same range. One 

 of the most common species in cultivation and exten- 

 sively hybridized with P. Nepalensis, giving rise to 

 most of the hybrid Potentillas of the trade. 



9. Nepalensis, Hook. (P. formbsa, Don. P. coccinea, 

 Hoffm.). Erect, 1K-2 ft. high, from a woody rootstock, 

 few-fid., clothed with long, soft, spreading hairs, leafy- 

 branched: lower Ivs. 5-7-foliate, often 12 in. long; Ifts. 

 (2-3 in. long) obovate or elliptic-obovate, acute or obtuse, 

 coarsely serrate, green, base entire: fls. 8-12 lines broad, 

 purple; petals obcordate, twice the length of the acute 

 sepals; bracteoles obtuse: akenes minute, glabrous, 

 wrinkled; receptacle hairy. May, June. Himalayas. 

 A fine species. 



10. Thiirberi, Gray. Similar to the last, but stem 

 ascending, more slender and finely pubescent: Ivs. 

 little paler beneath, 1-2 in. long, coarsely toothed or 

 almost crenate, thinner, smaller and less veiny: brac- 

 teoles lanceolate, acute. June, August. Southwestern 

 U. S. Good for border planting. 



11. v6rna, Linn. Stems 4-10 in. long, spreading or 

 procumbent, sometimes creeping, forming a thick 

 turf, much branched from the base, more or less hispid: 

 radical Ivs. small; Ifts. 5-7, broadly obovate-cuneiform, 

 dentate, 4-6 lines long: upper Ivs. sessile, ternate: fls. 

 many, of medium size, obscurely cymose; petals obcor- 

 date, little exceeding the. calyx; bracteoles similar to 

 the sepals; akenes smooth; receptacle hairy. April, 

 May. Dry or stony places, Europe. For banks and 

 rockeries. 



12. Pyrenaica, Ram. Stem branched below, 6-15 in. 

 long, decumbent at base, then ascending: radical Ivs. 

 long-petioled, hirsute or nearly glabrous; Ifts. oblong, 

 toothed above with subacute teeth, terminal tooth of 

 equal size; stem-lvs. few, similar: Ivs. numerous; sepals 

 and bracteoles similar, acutish ; petals longer than the 

 calyx, obcordate: carpels smooth; receptacle hairy. 

 Aug. Europe. Larger than the last and less prostrate: 

 Ifts. larger, more oblong: fls. larger. 



13. lacinidsa, Wald. & Kit. (P. laciniata, Amer. 

 Hort. ?). Erect and forming clumps 1-2 ft. high, spar- 

 ingly hirsute, reddish: Ivs. with 5-8 broadly oblanceo- 

 late-oblong, 2-3-in. long, deeply laciniate-pinnatifid and 

 pilose Ifts. : fls. in much -branched cymes ; sepals lanceo- 

 late; petals bright yellow, emarginate, much longer than 

 the calyx: akenes rugose; style terminal. Hungary; 

 grows well in dry ground. Closely related to P. recta. 

 Differs from the two preceding in the larger size, stiff, 

 erect habit, larger Ivs. and rugose akenes. 



14. gracilis, Dougl. Erect and rather tall (about 2 ft. 

 high), more or less whitened with silky hairs and to- 

 mentum: basal Ivs. long-petioled; Ifts. obovate or 

 oblanceolate, 1-2 in. long, deeply and regularly incised- 

 dentate, silky above, rarely glabrous, white -tomentose 

 beneath; stem-lvs. similar but smaller: fls. many in a 

 terminal cyme; corolla 6-9 lines broad, showy; petals 

 obcordate, exceeding the acuminate sepals: carpels 

 glabrous. Western N. Amer. Some specimens in cult, 

 may be P. Blaschkeana, Turc. 



15. arg6ntea, Linn. Ascending or procumbent, tufted, 

 branched from the base, 4-12 in. long, more or less 

 white-tomentose, leafy: Ifts. 6-12 lines long, obovate- 



oblanceolate, cuneate, deeply incised with narrow teeth 

 and revolute margins, dark green above, white beneath: 

 fls. few, cymose, 2-4 lines broad; sepals ovate-acute, 

 slightly shorter than the rounded petals ; styles filiform, 

 terminal: akenes glabrous. May-Sept. Dry, sterile soil 

 throughout the whole north temperate zone. 



16. Hybrid Potentillas, originally from P. argyro- 

 phylla, var. atrosanguinea, and P. Nepalensis (see 

 Gn. 16:207): Single-flowered. Hapwoodiana, Ifts. 5-6, 

 petals at base deep rose, at center pale rose, margins 

 whitish; Russelliana, scarlet-fire-red, large: Ifts. 3. 

 Double- f low ered. Ricolor Plena, orange and vermilion ; 

 Cardinale, brilliant cardinal; Dr. Andre", golden yel- 

 low, suffused with vermilion; Eldorado, purple suf- 

 fused with yellow; Emile, bright bronzy red; Gloire 

 de Nancy, golden yellow; Hamlet, dark carmine; 

 Hybrida, name applied to various hybrids, R. H. 1890, p. 

 305; Jeane Salter, orange shaded scarlet; Le Vesuve, 

 floriferous, light red margined with yellow or scarlet; 

 Mars, dark velvety red; M. Daudin, beautiful amber; 

 O'Briana, pink and salmon; Perfecta, maroon shaded 

 lemon; Purpurea, deep purple; Purpurea lutea plena, 

 dark purple, double; Versicolor, carmine and yellow- 

 flaked; Victor Lemoine, light red striped with yellow; 

 Wm. Rollinson, mahogany brown suffused with orange. 



P. anserlna, Linn. SILVER-WEED. Spreading by runners, 

 low, white-tomentose: Ivs. radical, pinnate: fls. yellow. 

 Gravelly lake shores. Very decorative. Eu., N. Amer. P. 

 Canadensis, Linn. Prostrate or creeping: Ivs. green, palmately 

 3-5-foliolate: ns. few, yellow. N. Amer. Good for dry, sterile 

 soil. Mn. 3:38. P. Milleri, Hort. A trade name not deter- 

 mined. Woolsonsays, "Colorado; 12-18 in. high. Plant densely 

 white-tomentose, branching. Fls. bright yellow, a half inch or 

 more across." P. recta, Linn. Close to P. laciniosa, tall, with 

 handsome palmate foliage: fls. deep yellow, worthy of cult. 

 Eu. P. Salesovidna. See B.M. 7258. P. sulphured, Lam. 

 Similar to P. recta, but fls. pale yellow and larger. Fine deco- 

 rative plant. Eu., introduced in Amer. K. M. WlEGAND 



POTfiRIUM (Greek for drinking cup; because the 

 foliage of one species was used in the preparation of a 

 medicinal drink). Bosdcew. Linnaeus placed certain 

 rosaceous plants in the genera Poterium and San- 

 guisorba, the latter having precedence of publication. 

 Many subsequent authors have united these genera, and 

 they are so treated in Gray's Manual. Focke, however 

 (Eiigler and Prantl, Die Natiirlichen Pflanzenfamilien), 

 re-defines the genus Poterium to include one species, 

 the P. spinosum of South Europe, allowing the other 

 species to remain in Sanguisorba. As thus understood, 

 Poterium is monoecious, the lower fls. in the spike 

 staminate, the upper pistillate, the stamens many and 

 hanging, the styles 2, the fr. somewhat fleshy, colored, 

 and inclosed in the calyx, the leaves pinnate. P. spinosum, 

 Linn., is a small spiny shrub with nearly glabrous 

 serrate leaflets, somewhat downy branches, small green- 

 ish fls. in oblong spikes and reddish berry-like fr. It is 

 offered in S. Calif. Grows 3 ft., the branchlets ending 

 in spines. Said to be a very interesting ornamental 

 under-shrub. 



For P. Canadense and P. Sanguisorba, see Sanguis- 

 orba. L . H . B. 



POTHOS (Potha is said to be a Ceylonese name). 

 Aracece. Between 30 and 40 tall-climbing branching 

 shrubs (more or less herbaceous as known in cultiva- 

 tion) of the oriental tropics; leaves thick and often 

 shining, entire or lobed, sometimes blotched or varie- 

 gated. The species are warmhouse foliage plants, re- 

 quiring the same general treatment as Philodendron 

 (which see). Five names are in the American trade, 

 but not all of them belong to Pothos. In fact, the genus 

 Pothos is very ill-defined in cultivation because species 

 are named before flowers and fruits are known and 

 determinations are often wrongly made. Some of them 

 are to be referred to Scindapsus and others perhaps to 

 Rhaphidophora. The fls. are small and perfect, crowded 

 on a spadix, with 6 perianth-segments and 6 stamens, 

 the ovary 3-loculed and with a rounded or mushroom- 

 like sessile stigma: fr. a 1-3-seeded berry: spathe 

 usually persistent and wide-spreading or deflexed at 

 maturity. Rhaphidophora has an oblong or linear stigma. 

 The species of Pothos send out cord-like roots that cling 

 to damp walls. For P. argyrwa, see Scindapsus pictus, 

 var. For monograph, see Engler. DC. Monogr. Phaner. 2. 



