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2. Pothos dzui P.C.
Boyce, sp. nov.
Pothos dzui pedunculo longo, spatha pro ratione parva
et stipite longo P. grandem arcte simulans, sed ab eo spadice
crasso cylindrico inaeque in stipite prominenti longe decurrenti atque
spatha valde reflexa facile separetur; P. cylindricum, speciem
Philippinensem, praeterea spadice cylindrico simulans, sed ab ea lamina
late elliptica atque petiolo brevi distinguitur. Typus. Vietnam,
Gia Lai, Mangyang, Chui Ta Moi, Nguyen Thi Nhan 532 (holo HN!),
Robust (homeophyllous?) root-climbing liane of unknown ultimate height.
Eocaul, juvenile shoot and mature sterile shoot not observed; stem
of fertile shoot to 5 mm diam., terete to somewhat angled in cross
section. Leaves drying pale brown; petiole 10 55 x 2
10 mm, broadly winged, obovate-oblong oblong-triangular, with 2
3 secondary veins and numerous veinlets per side, all veins prominent,
especially in dried material, base decurrent, apex truncate, rounded
or very slightly auriculate; lamina 30 70 x 90 170 mm,
elliptic to ovate with 2 4 intramarginal veins per side, these
arising from the base and immediately diverging and then reaching
the leaf tip, additional veins arising obliquely from the midrib,
remaining parallel with numerous veins arising from them, base rounded
to acute, apex attenuate-mucronate to acute or attenuate, minutely
tubulate. Flowering shoot much abbreviated, arising from the proximal
leaf axils of fertile shoots, bearing a minute prophyll and a few
3 10 mm sequentially longer cataphylls. Inflorescence solitary;
peduncle 40 55 x 1.5 2 mm, rather stout, erect, twisting
basally to present the inflorescences above the flowering shoot; spathe
17 20 x c. 20 mm, narrowly ovate, concave, prominently parallel-veined
in dry material, margins strongly inrolled, base shallowly, cordate,
clasping and decurrent on the peduncle, apex acute with a stout mucro;
spadix stipitate; stipe c. 22 x 2 mm, terete in cross section, erect,
straight; fertile portion 25 30 x 5 7 mm, stoutly cylindrical,
bluntly rounded, unequally long-decurrent on the stipe. Flowers c.
1 mm diam.; tepals 1 x 0.3 mm, oblong-cymbiform, apex fornicate, triangular,
truncate; stamens 1 2 x c. 0.25 mm, filaments strap-shaped,
thecae c. 0.2 mm diam.; ovary 1 1.5 x 0.25 0.75 mm,
compressed ellipsoid; stylar region truncate; stigma punctiform, margins
Habitat & Ecology Unknown.
Notes Pothos dzui is a remarkable species known
from a single collection of a solitary mature flowering branch with
two mid-anthesis inflorescences. The inflorescence morphology (long
peduncle, relatively small spathe and long stipe) is reminiscent of
P. grandis from which P.
dzui differs by the stout cylindrical spadix unequally long-decurrent
on a prominent stipe and by the strongly reflexed spathe (vs. P.
grandis in which the spadix is ovoid to clavate and the minutely
cochleate at the insertion on a relatively short stipe and the spathe
spreading to slightly reflexed). In the character of the cylindrical
spadix P. dzui resembles P. cylindricus
Presl (Philippines) from which it differs by the broad elliptic leaf
lamina and short petiole.
It gives me considerable pleasure to name this species for Nguyen
Van Dzu, my Vietnamese collaborator, expert on geophytic Indochinese
aroids and excellent field companion, who first drew my attention
to the collection in HN.
VIETNAM. Gia Lai: Mangyang, Chui Ta Moi, Nguyen Thi Nhan 532 (fl.)