1960] 



SPATHIPHYLLUM 



9 



I am grateful to Mr Alfred B. Graf for making available for study all the 

 aroids growing at the Julius Koehrs Company, Rutherford, New Jersey, and to 

 the numerous other horticulturists who have shared their knowledge and col- 

 lections in an effort to clarify the nomenclature of cultivated plants. 



SYSTEMATIC TREATMENT 



Spathiphyllum Schott, Melet. Bot. 22. 1832. 



Hydnostachyon Liebm. Vid. Meddel. 1-2: 23. 1849. 

 Massowia K. Koch, Bot. Zeit. 10: 277-278. 1852. 



Spathiphyllopsis Teijsm. & Binn. Natuurk. Tijdsch. Ned. Indie 25: 400. 1863. 

 Amomophyllum Engl. Gard. Chron. II. 7: 139. 1877. 



Perianth of 4-6 (-7) green or white segments, separate or conglutinate or 

 connate toward the base, apically thickened and often truncate, inflexed, im- 

 bricate, accrescent in age, or the perianth a 4-6-sided fleshy cup, the apex 

 truncate ; pistil commonly white in flower, green in age, subcylindric or obpyra- 

 midal, apically truncate or attenuate-conic, equaling or exceeding the perianth, 

 the stigma coronate or elevated, (2-)3-lobed, often brash-like; ovary (2-)3- 

 locular, the ovary walls containing' trichosclereids ; septa membranous, ± free 

 from one another above, connate below along their inner margins, forming a 

 hollow, cylindrical axis (axile placenta) bearing the ovules, (the septum centrally 

 pierced in 2-locular ovaries) ; ovules ± oblong in lateral outline, anatropous, 

 (8-) 5-1 per locule, superposed or collateral, imbedded in a transparent, insoluble 

 but hydrophilous matrix that fills each locule ; placentation axile ; stamens as 

 many as the perianth segments and opposite them, the filaments broad, oblong, 

 lengthening in age, the anthers basi-dorsifixed, not versatile, yellow or whitish, 

 nearly as wide as long, 2-celled, the sides subparallel, their dehiscense longi- 

 tudinal and extrorse; fruiting spadix smooth or tuberculate; fruit obovoid to 

 ovoid, often long- or short-rostrate ; seeds few to many, oblique-ovoid to reniform 

 or oblong in profile, often very angular, yellowish, the surface smooth or 

 verruculose between ± vertical rows of foveola. 



Glabrous herbs 2-12 dm tall, the many leaves arising from an abbreviated 

 rhizome partially visible above the soil and rooted on the lower side ; cataphylls 

 very narrowly attenuate-lanceolate, abaxially bicarinate, often two-thirds as long 

 as the pt tiole or longer ; petioles mostly equaling or longer than the blade, terete 

 above, alate and vaginate below, equitant, apically geniculate ; the geniculum to 

 5 cm long, sulcate above and occasionally alate ; leaf-blades arching outwardly, 

 simple, entire, marginally undulate, lanceolate or oblong to elliptic or oblanceo- 

 late, 2-many times longer than wide, the apex acuminate-cuspidate and the base 

 attenuate or acute to obtuse or subrotund, the midrib wide, flattened and promi- 

 nent above, very conspicuous beneath, triangular to semicircular in cross section, 

 the few to many pairs of primary lateral veins subparallel and arcuate toward 

 the apex, impressed upon the usually glossy upper surface, salient on the paler 

 under surface, with usually one secondary and two tertiary lateral veins between 

 two primary veins. Inflorescence scapoid, the peduncle geniculate at the apex, 

 commonly holding the spathe and spadix erect above the arched foilage ; spathe 

 at first convolute, becoming cucullate or plane and erect or reflexed, white or 

 green, lanceolate or elliptic to ovate, rarely oblanceolate, the apex pointed, the 

 base acute to obtuse and decurrent upon the peduncle or non-decurrent ; spadix 

 terminal on the peduncle, erect, cylindrical throughout, (the flowers congested or 

 loosely arranged), shorter than the spathe, sessile or on a free stipe to 4 cm long. 



