Aglaonema nebulosum N. E. Br.

Aglaonema nebulosum

Aglaonema nebulosum N. E. Brown, 1887, p. 67, pl. 24.

Stem erect, 10–60 cm tall, 0.5–1.0 cm thick. Internodes 0.5–2.0 cm long. Petioles 2–5 cm long, (0.1) 0.2–0.4 times as long as the leaf-blade. Sheaths membranous, short, 0.5–1.5 (2) cm long, 0.15–0.3 (0.6) times as long as the petiole. Leaf-blades dull above, oblanceolate to narrowly elliptic-oblong, rarely obovate to elliptic, (6.5) 9–18 (20) cm long, (2.5) 3–5.5 (7) cm wide, length/width ratio 1: 2.5–3.5; base obtuse to acute; apex often apiculate, acuminate to abruptly acuminate; variegation rare, then in the form of ashy or silvery irregular blotches on the upper leaf surface; venation usually strongly differentiated into 5–10 or more pairs of primary lateral veins diverging from the midrib at 40°–60°. Peduncles solitary, rarely 2 together, 2–4.5 cm long, equaling the petioles. Spathe apiculate, light green to whitish, globose, 1.7–2.7 cm long, to 4 cm wide, decurrent for 0.2–0.5 cm. Stipe 0.3–1.0 cm long. Spadix clavate, exserted from spathe for 0.5 cm at anthesis, 1.2–2.0 cm long; pistillate portion 0.3–0.6 cm long, ca. 0.6 cm thick, pistils 10–20; staminate portion 0.9–1.5 cm long, 0.3–0.4 cm thick at base, 0.6–0.8 cm wide at or above middle, white. Fruits dark red, 0.7–2.0 cm long, 0.4–0.9 cm thick.

DISTRIBUTION.—Malaya, Borneo, and islands off the east coast of Sumatra (Figure 7).

HABITAT.—Peat and freshwater forests.

FLOWERING TIME.—Nonseasonal.

Aglaonema nebulosum N. E. Brown has been taxonomically confused since its inception. It originally was described from vegetative material cultivated by Linden and was reported to have originated in Java. All available evidence is against this source, for three other cultivated specimens sent earlier to Brown by Linden and Bull were noted as having originated from Borneo, and the species is not known to reach Java. It is not clear to me why Brown chose to describe only vegetative material and chose to overlook the flowering material of A. nebulosum, which he had already prepared. It is this flowering material that makes it possible to identify A. nebulosum with later collections from the wild and with epithets subsequently applied to the species.

Hooker (1893) did not include A. nebulosum, but had three nonvariegated collections of material assignable to this species, each of which he recognized as the type of a species: A. minus, A. nanum, and A. scortechinii. Ridley (1907) reduced A. nanum and A. scortechinii to varieties of A. minus. Engler (1915), who did not cite Ridley’s work, recognized all the four species A. nebulosum, A. minus, A. nanum, and A. scortechinii, noting that A. nebulosum and A. scortechinii were “Species imperfecte cognita.” Ridley (1925) added a new element of confusion when he reduced A. minus to synonymy with A. pictum and recognized A. nanum and A. scortechinii as varieties of A. pictum. Aglaonema pictum is, to be sure, closely related to A. nebulosum but seems to be distinct. In A. pictum the petiolar sheath is consistently well over half the petiole length while in A. nebulosum the sheath is rarely over one-third as long as the petiole. Apparently Ridley confused the species because variegation patterns in the two species are almost identical.

Aglaonema vittatum may be confused with A. nebulosum since both have short sheaths and overlapping distributions, but the spadix is not exserted in A. vittatum as it is in A . nebulosum .

Aglaonema nebulosum f. nanum (Hooker f.) Nicolson

Aglaonema nanum Hooker f., 1893, p. 530.

A. minus Hooker f., 1893, p. 530.

A. scortechinii Hooker f., 1893, p. 530.

A. minus var. scortechinii (Hooker f.) Ridley 1907, p. 22.

A. minus var. nanum (Hooker f.) Ridley, 1907, p. 22.

A. obovatum van Alderwerelt van Rosenburgh, 1922, p. 322.

A. pictum var. scortechinii (Hooker f.) Ridley, 1925, p. 102.

A. pictum var. nanum (Hooker f.) Ridley, 1925, p. 102.

Leaf variegation none.

TYPE COLLECTION.—Malaya [Selangor], Ulu Bubong, July 1886, King’s Collector 10421 (holotype: K; isotypes: BM, CAL, SING). In this case, Dr. King’s collector was Kunstler.

DISTRIBUTION.—Malaysia, Borneo, and islands off the eastern coast of Sumatra. Highest elevation reported is 2000 ft (Derry 613) on Mt. Ophir, Malacca.

FLOWERING TIME.—Appears to be nonseasonal.

The type of Aglaonema minus is: Singapore, October 1822, Wallich, E. India Co. 8960A (holotype: K). The type is in abortive fruit and the smallish leaves have three to four pairs of weakly differentiated veins. I regard this specimen as a poorly developed individual of A. nebulosum, which generally has six or more rather strongly differentiated pairs of veins.

The type of Aglaonema scortechinii is: Perak [no date], Scortechini 255 (holotype: K, isotype: CAL). The Kew specimen is regarded as the holotype since it was annotated by N. E. Brown, who assisted Hooker with Araceae for the Flora of British India. The leaves of this specimen are ovate (2.0–2.4 times longer than broad) rather than oblanceolate; however, some of these lower leaves are broader than the upper, more vigorous leaves, making it difficult to justify maintenance of A. scortechinii solely on the basis of leaf shape.

The type of Aglaonema obovatum is: Indonesia, Lingga Archipel, Pulo Lingga, Kampong Panggak, 30 m, Sago bosch, 27 July 1916, Biinnemeijer 7039 (holotype: BO). Alderwerelt van Rosenburgh did not comment about the relationships of his species nor indicate what was distinctive about it. I cannot maintain it since the type is adequate and falls completely within my concept of A. nebulosum f. nanum.

Aglaonema nebulosum is a species of flowering plant in the family Araceae. It is native to Assam, India.