Monographs Details: Spathantheum lanceaefolium (Jacq.) Schott
Authority: Bunting, George S. 1960. A revision of Spathiphyllum (Araceae). Mem. New York Bot. Gard. 10: 1-54.
Family:Araceae
Description:Species Description - Leaf-blade oblong- or elliptic Janceolate, more than 30 cm long and ca. 10 cm wide, the apex acuminate, the base (apparently) acute, the many primary lateral veins arising at an angle of 45-55°; petiole shorter than or equaling the blade, alate nearly to the base of the geniculum; geniculum ca. 1.5 cm long. Peduncle somewhat longer than the petiole; spathe oblong-lanceolate, ca. 15 cm long and 5 cm wide, the apex acuminate-cuspidate, the base (apparently) acute, decurrent on the peduncle ea. 2 cm; spadix; 3-4 cm long, on a stipe ca. 1 cm long; perianth segments separate or possibly conglutinate, green at the apex; pistil elongate-conic, exceeding the perianth, the locules of the ovarv 2-ovulate.

Discussion:

Figure 5.

Dracontium lanceaefolium .Jacq. Collectanea 4: 118. 1790.

Massowia laneeaefolia C. Koch, Bonplandia 4: 12. 1856.

Type: Jacquin, Ic. PI. Rar. 3: pl. 612 (1786-1793). This is an excellent color plate, with enlargements of a single flower. The original description states that the flowers have five perianth segments, although the plate suggests that they have only four. Since all the segments are not of the same size, it is possible that two more segments would be hidden behind the pistil in that illustration. The holotype, Brcdemeyer s.n., collected near Caracas, was probably burned at Vienna or Berlin.

The description presented above was drawn from the Jacquin plate and from the descriptions of various writers who probably examined the Bredemeyer specimen.

S. lanceaefolium has remained an unfamiliar species, known only from the type collection. N o w the type specimen has been destroyed. No specimens have been identified as S. lanceaefolium during this investigation. Sagot 769 was referred to this species by other workers, but its non-decurrent spathe and the characteristics of its pistil lead m e to identify that specimen unquestionably as S. humboldtii.

Despite the lack of representative specimens, Jacquin's description and fine illustration of S. lanceaefolium serve adequately to define the genus Spathiphyllum, and consequently to save the generic name. It is noteworthy that an illustration of this species presented by Schott (Aroid. 1: 2. pZ. 3B. 1853) is not in complete agreement with that of Jacquin lending more uncertainty to the exact character of S. lanceaefolium. The differences between the illustrations are compared below.

Jacquin

Specimen flowering

Stipe ca. 1 cm long

Spathe oblong-lanceolate

Style blunt-rounded

Schott

Specimen fruiting

Stipe longer

Spathe elliptic-lanceolate

Style attenuate

This species appears to be closely related to three other species. The acute base of the leaf-blade distinguishes S. lanceaefolium from both S. kochii and S. phryniifolium, in which the leaf-blade is obtuse at the base. Differences between S. lanceaefolium and S. blandum are uncertain. In the absence of definitive material of S. lanceaefolium, and considering their different geography, I have continued to recognize each as a species.