2776 



POTENTILLA 



POTHOS 



appendages usually lobed; petals obovate, entire, ex- 

 ceeding the sepals, golden yellow; carpels at maturity 

 glabrous, thick, ovoid, corky, dorsally furrowed; style 

 lateral, filiform. May- Aug. Gravelly, more or less cal- 

 careous shores. Most widespread of all potentillas, 

 through the cold and temperate portions of all countries 

 except possibly Afr. Very decorative. 



32. pacifica, Howell. Similar to P. Anserina; but 

 sts., peduncles, petioles, and rachis glabrous or early 

 glabrate: Ifts. dull-tomentose beneath: achenes later- 

 ally compressed, firmer, rounded on the back, not fur- 

 rowed. Along the coast of temperate and arctic E. and 

 W. Amer., and E. Asia. This species may be in the 

 trade as P. Anserina. 



33. Gordonii, Baill. (Ivesia Gordonii, Torr. & Gray. 

 Horkelia Gordonii, Hook.). Caudex stout, woody, and 

 cespitose: sts. erect, 4-12 in. high, and, like the Ivs., 

 glandular-pubescent or glabrous: Ivs. pinnate, mostly 

 basal, numerous; Ifts. 10-20, divided into 3-5 oblong 

 or linear segms.; cauline Ivs. few. very small: fls. small 

 and inconspicuous, in a crowded cyme; petals yellow, 

 spatulate, shorter than the sepals; stamens 5-20, 

 inserted on the edge of the cup-shaped receptacle at a 

 distance from the carpels; style filiform, basal. Subal- 

 pine W. U. S. Forms dense mats in dry soil. This spe- 

 cies belongs properly to Horkelia (a genus apparently 

 not known to the gardeners) and is generically distinct 

 from Potentilla because of the more deeply cup-shaped 

 receptacle. It is, however, known in the trade as a 

 potentilla. 



Following are some of the hybrid potentillas, the exact botanical 

 status of which has not been worked out and which have not been 

 standardized as to nomenclature: P. tricolor (P. argyrophylla X P. 

 atrosanguinea, according to Wolf), orange and vermilion. P. 

 cardinale (P. atrosanguinea x P. nepalensis, according to Wolf), 

 brilliant cardinal. Dr. Andre, golden yellow suffused with vermilion. 

 Eldorado, purple suffused with yellow. Emile, bright bronzy 

 red. Gloire de Nancy, golden yellow. Hamlet, dark carmine. P. 

 Hopwoodiana (P. nepalensis X P. recta, according to Wolf). Lfts. 

 5-6: petals at base deep rose, at center pale rose, margins whitish. 

 P. htfbrida, name applied to various hybrids. R.H. 1890, p. 305. 

 Gn. 16:462; 25:514. Jeane Salter, orange, shaded scarlet. Le 

 Vesuve, floriferous, light red margined with yellow or scarlet. P. 

 Mac Nabiana (P. argyrophylla X P. atrosanguinea, according to 

 Wolf). Mars, dark velvety red. M. Daudin, beautiful amber. 

 O'Briana, pink and salmon. P. perfecta, maroon, shaded lemon. 

 P. purpurea, deep purple. P. verslcolor, carmine- and yellow- 

 flaked. Victor Lemoine, light red striped with yellow. Wm. 

 Rollinson, mahogany-brown, suffused with orange. 



The status of the following trade names cannot be determined: 

 P. amaena, P. cauc&sicum, P. concolor, P. lanugindsa, P. minima, 

 P. nesstnsis, P. splendent. R M WlEQAND 



3159. Pothos aureus of the horticulturists. ( X K) 



POTERIUM (Greek for drinking cup; because the 

 foliage of one species was used in the preparation of a 

 medicinal drink). Rosacese. 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. 

 Focke, however (Engler & Prantl, Die Natiirlichen 

 Pflanzenfamilien), re-defines the genus Poterium to 

 include one species, the P. spinosum of S. Eu., 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 Ivs. 

 pinnate. These plants are known as burriet, although 

 the name applies more correctly to Sanguisorba alone. 

 P. spinosum, Linn., is a small spiny shrub with nearly 

 glabrous serrate Ifts., somewhat downy branches, small 

 greenish 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 orna- 

 mental undershrub. Recently P. obttlsum, Franch. & 

 Sav. (P. obtusdtum, Hort. Sanguisorba obtusa, Maxim.), 

 has been offered abroad : it is from Japan, said to be the 

 finest of the burnets yet introduced: 3 ft. : Ivs. long, pin- 

 nate, Ifts. about 6 pairs, oblong, rounded at end, ser- 

 rate, petioluled: fl.-sts. much branched, the crimson 

 spikes about 3 in. long and 1 in. diam. Summer. G.C. 

 III. 59:2. For P. canadense and P. Sanguisorba, see 

 Sanguisorba. L. H. B. 



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

 Aracese. Tall-climbing branching shrubs (more or less 

 herbaceous as known in cultivation) of the oriental 

 tropics. 



Leaves thick and often shining, entire or lobed, 

 sometimes blotched or variegated: fls. small and per- 

 fect, crowded on a spadix, with 6 perianth-segms. 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. About 50 species. Several names are in the 

 hort. trade, but not all of them belong to Pothos. In 

 fact, the genus Pothos is very ill-defined in cult, be- 

 cause species are named before fls. and frs. are known 

 and determinations are often wrongly made. Some of 

 them are to be referred to Scindapsus and others per- 

 haps to Rhaphidophora. The species of Pothos send 

 out cord-like roots that cling to damp walls. For P. 

 argyrosa, see Scindapsus pictuj var. For monograph, 

 see Engler, Das Pflanzenreich, IV. 23 B (1905). They 

 are warmhouse foliage plants and require the same 

 general treatment as Philodendron. 



A. Lvs. green, not banded or mottled. 



nitens, Bull. Lvs. obliquely ovate-acute, cordate 

 at base, shining purplish green; needs further botani- 

 cal definition. Malaya. 



AA. Lvs. mottled or banded. 



afcreus, Lind. Fig. 3159. Strong evergreen climber 

 with cordate-ovate-acute Ivs., which are variously 

 blotched and mottled with yellowish white, the body 

 color being bright green. Solomon Isl. I.H. 27:381. 

 S.H. 1:334. The generic position of this plant which 

 is one of the commonest ones in cult. is in doubt. It 

 probably belongs to Scindapsus so treated by Engler. 

 In a dark place the handsome markings of the Ivs. 

 tend to disappear. Branches will grow in water for a 

 time. Prop, by cuttings or layers. 



argenteus, Bull. Lvs. obliquely ovate-acuminate, sil- 

 very gray, with a deep green margin and a deep green 

 band along the midrib ; needs further definition. Borneo. 



P. celatocaiilis, N. E. Br.=Monstera latevaginata. P. Loureiri, 

 Hook. & Arn. Climbing, branched, with aerial roots: petioles 4-5 



