Research Article
Research Article
A new species of Typhonium (Araceae) from Vietnam
expand article infoHong Truong Luu§, Nga Nguyen-Phi|, Quoc Dat Nguyen, Hieu Cuong Nguyen, Hong Thien Van#, Xuan Bach Nguyen-Le
‡ Vietnam Academy of Science and Technology, Ho Chi Minh City, Vietnam
§ Graduate University of Science and Technology, Ho Chi Minh City, Vietnam
| Vietnam National University, Ho Chi Minh City, Vietnam
¶ University of Science, Ho Chi Minh City, Vietnam
# Industrial University of Ho Chi Minh City, Ho Chi Minh City, Vietnam
Open Access


Typhonium obtusum is described as a new species endemic to Vietnam. It is unique in the genus in having an oblong-elliptic spathe limb with an obtuse apex and yellowish-greenish filiform staminodes with a down-curved acumen. The ecology, distribution and assessment of the conservation status of the new taxon, as well as a key to all known Typhonium species in Vietnam, are provided.

Key words

Araceae, endemic, new species, Typhonium obtusum, Vietnam


The genus Typhonium (Schott 1829) of the Araceae is estimated to have about 80 to 100 species distributed over the world (Sriboonma et al. 1994; Hetterscheid and Boyce 2000; Boyce et al. 2012; Hetterscheid 2013; Low et al. 2021; POWO 2024). A latest checklist of 70 accepted Typhonium species names is provided online (POWO 2024). Indochina was proved to be the centre of Typhonium diversity with about 40 species described (Low et al. 2021; Pham et al. 2023). The genus was revised several times for Vietnam (Gagnepain 1942a, b; Pham-Hoang 1993, 2003; Nguyen and Vu 2004; Nguyen 2005, 2017). In fact, the last three decades have witnessed many new discoveries which make the total number of Typhonium in the country to be 23 (Nguyen and Croat 1997; Hetterscheid and Boyce 2000; Hetterscheid and Nguyen 2001; Nguyen 2005, 2008; Nguyen and Croat 2010; Hetterscheid 2013; Luu et al. 2017; Van et al. 2017, 2021; Nguyen et al. 2021, 2022a, b; Nguyen-Phi et al. 2023; Pham et al. 2023; Serebryanyi et al. 2023).

As part of ongoing study of Typhonium in Vietnam, we have collected several putatively new taxa, one of which was found in Phu Yen Province, central Vietnam. At the first glance, the plant looks like T. rhizomatosum A.Galloway and P.Schmidt (Galloway 2012) and T. cordifolium S.Y.Hu (Hu 1968) as all of them share the following in common: the general appearance of leaves and spathe limbs and the structure of inflorescences (Nguyen et al. 2022b; Nguyen-Phi et al. 2023). However, after our careful examination of its morphological characteristics, it turns out that our plant is, indeed, a new species that we describe here, based on living collections.

Material and methods

The studied material was collected from Phu Yen Province, Central Vietnam. Specimens were sampled and processed using methods guided by the Royal Botanic Gardens, Kew (Bridson and Forman 1999); the herbarium acronyms follow Thiers (2024). Detailed photographs and description of taxonomically important characters of the new species were taken of fresh materials in the field using a digital camera. Taxonomic identification was based on morphological vegetative and reproductive characters following the aforementioned literature.

Taxonomic treatment

Typhonium obtusum Luu, X.B.Nguyen-Le & H.C.Nguyen, sp. nov.

Fig. 1


Vietnam. Phu Yen Province, Tay Hoa District, Hoa Thinh Ward; 12°54'30.1"N, 109°14'15.1"E, 30 m elevation; 5 August 2015; Nguyen Le Xuan Bach & Nguyen Hieu Cuong PY495-505 (holotype SGN!; isotypes SGN!, PHH!).


Typhonium obtusum is morphologically similar to T. rhizomatosum and T. cordifolium in having ovate leaf blades with cordate base, oblong and elongate spathe limb as long as the spadix and an elongated fusiform spadix appendix. However, the novel taxon can be distinguished from T. rhizomatosum by its subcylindrical (vs. globose to subglobose) tubers without (vs. with) rhizomatous offsets, stipitate and fusiform (vs. sessile and conical) spadix appendix) and oblong-elliptic (vs. narrowly triangular ovate) spathe limb and from T. cordifolium by its subcylindrical (vs. subglobose) tubers, leaves without (vs. with) adventitious buds, oblong-elliptic (vs. narrowly triangular ovate) spathe limb and stipitate and fusiform (vs. sessile and cylindrical) spadix appendix.

Figure 1. 

Typhonium obtusum A whole plants B stem C different forms of leaf blade D inflorescence E spathe and spadix F male, sterile and female zones G stamens H thecae, opened I pistils, cross-dissection J fruits.


Herbs, seasonally dormant, 10–17 cm tall; tuber underground, subcylindrical, fleshy, 2–2.5 cm long, 1–1.5 cm in diameter, with many filiform roots. Leaves 2–3 together. Petiole smooth, slender, 5–9 cm long, 1.8–2.2 mm in diameter, white to brown at base, green towards the apex. Leaf blade entire or trilobate, strongly cordate, glabrous, adaxially green, abaxially lighter green, concave, 3.2–4.7 cm long, 3–4 cm wide; entire leaf blade ovate, rounded at apex, venation pinnate with abaxially prominent midrib, lateral veins 5–8, brochiododromous, collective veins at 2–5 mm from margin; anterior lobes ovate, broadly elliptic to obovate, 2.5–3.7 cm long, 2.3–3.0 cm wide, obtuse to rounded at apex with a minute mucro, mid-rib abaxially prominent, lateral veins 4–6, brochiododromous, collective veins at 1–2 mm from margin; lateral lobes elliptic to ovate, 2.2–3.1 cm long, 0.6–1.6 cm wide, obtuse at apex, oblique at base. Inflorescences solitary; peduncle white, 2.5–6 cm long, ca. 4 mm in diameter; spathe 5–6 cm long, tube and limb separated by a constriction, outside green-brown, inside purple-brown; spathe tube ovoid, 1.1–1.3 cm long, 7–8 mm in diameter; spathe limb oblong-elliptic, 4–4.5 cm long, 1.1–1.3 cm wide, obtuse at apex, hardly open at base at anthesis; spadix equal or slightly shorter than spathe, sessile; female part conical, 1.6–2 mm long, 3.9–4.3 mm in diameter at the base, 2–3 mm in diameter at the top, with 3–4 rows of crowded pistils; ovary obovate, ca. 1 mm long, 0.6–0.8 mm in diameter, yellowish-greenish, with purple spots, unilocular, uniovulate placentation, transparently white; ovule light yellow, on a basal placenta and hold obliquely on a funicle; stigma sessile, disciform, 0.3–0.5 mm in diam., 0.1–0.2 mm high, light yellow, penicillate; interstice 1–1.3 cm long, lower part ca. 4 mm densely covered with staminodes, upper part naked, smooth, white to yellowish; staminodes filiform, subulate, 1–3 mm long, 0.4 mm in diameter, apically curved downward, yellowish-greenish; male part cylindrical, ca. 4.5 mm long, ca. 2.5 mm in diameter; stamens free, sparsely to (mostly) densely arranged; thecae globular, ca. 0.3 mm in diameter, dark purple, opening by apical slit; pollens translucent white; appendix stipitate, elongated fusiform, pale yellowish, 2.5–3.9 cm long, 2–3 mm in diameter, stipe ca. 3.5 mm long, pale yellow. Fruits ovoid to capsule-shaped, 3–4 mm long, 1.5–1.8 mm in diameter, white at base, green towards the apex with many dark purple spots.


The species is named for the obtuse apex of its spathe limb.

Vernacular name

Bán hạ mo tù (Vietnamese); Obtuse-spathed typhonium (English, here proposed).

Ecological notes

The new species was found growing in clumps on basalt soils in open places of rural farms. It appears in September to December and becomes dormant in January to August. Flowering and fruiting were seen in August.


Typhonium obtusum has been recorded only from the type locality.

Conservation status

Data Deficient (DD) (IUCN Standards and Petitions Subcommittee 2022). The new species has, so far, been found in one location and further inventory should be employed for a certain assessment.

Taxonomic notes

The key morphological similarities and differences of T. obtusum versus T. rhizomatosum and T. cordifolium are presented in the diagnosis. In addition, the two latter are different from the new species by their unique characters in the genus: T. cordifolium with adventitious buds appearing at the mature leaf blade apex or sometimes at the top of the sheath, while T. rhizomatosum often forms large colonies thanks to its rhizomatous offsettings (Murata et al. 2010; Boyce et al. 2012; Nguyen-Phi et al. 2023).

The new species may be morphologically close to T. hayatae Sribonnma & J.Murata (Sriboonma et al. 1994), T. inopinatum Prain (King and Prain 1898), T. medusae Hett. & Sookch. (Hetterscheid et al. 2001) and T. varians Hett. & Sookch. (Hetterscheid et al. 2001), as they have a short spathe limb and similar general shape and structure of the spadix and filiform staminodes. However, these species are easily distinguishable from the new taxon as they have elongate conical, sessile or shortly stipitate spadix appendix with truncate base. Furthermore, T. hayatae has globose tuber, long spadix appendix (6–14 cm) and spathe limb (12–26 cm); T. inopinatum has globose tuber, ovate-lanceolate spathe limb that is shorter than the spadix appendix and yellow staminodes; T. medusae has depressed tuber, velvety petioles, hairy leaf blades, orbicular spathe limb, pale yellow or cream staminodes and elongate conical appendix; T. varians has depressed tuber, dark grey spadix appendix 4.5–9 cm long, triangular ovate spathe limb of 7–14 cm length and 4–7.5 cm in diameter and pale pink anthers. Their different morphological characters are summarised in Table 1.

Table 1.

Morphological differences between Typhonium obtusum and close species.

T. obtusum T. hayatae T. inopinatum T. medusae T. varians T. rhizomatosum T. cordifolium
Tuber subcylindrical, without rhizomatous offsets globose, without rhizomatous offsets subcylindrical, globose, without rhizomatous offsets depressed, without rhizomatous offsets depressed, without rhizomatous offsets globose to subglobose, with rhizomatous offsets subglobose, without rhizomatous offsets
Leaf blade ovate, smooth ovate to triangular or hastate, smooth broadly triangular, 10 cm long, 14 cm wide, hairy broadly triangular, more or less distinctly trilobate to subpentalobate, smooth ovate to elliptical-ovate, smooth narrowly ovate elliptic to narrowly elliptic, acuminate, with a bulbil when mature
Spadix appendix 2.5–3.9 cm long, 0.2–0.3 cm in diameter, pale yellowish, fusiform, stipe ca. 0.35 cm long, base gradually narrowing 6–14 cm long, 0.5–1.5 cm in diameter, conical, stipe short, base truncate 4–6 cm long, 0.4–0.5 cm in diameter, yellow, yellowish-brown, elongate conical, subsessile, base truncate 1 cm long, 0.3 cm in diameter, reddish-brown, elongate conical, stipe 0.15 cm long, base truncate 4.5–9 cm long, to 1 cm in diameter, dark grey, elongate conical, stipe 0.5 cm long, base truncate 8 cm long, 0.35 cm in diameter, beige, conical, sessile, base truncate 3.6–7.7 cm long, 0.1–0.2 cm in diameter, brick orange, cylindrical, sessile, base gradually narrowing
Spathe tube ovoid, 1.1–1.3 cm long, 0.7–0.8 cm in diameter, green with brown dots oblong-ovoid 2.5–4.5 cm long, 1–2 cm wide, dark brownish-purple ovoid, 0.8‒1.5 cm long, ca. 1 cm in diameter, green ovoid, 1.8–2 cm long, 1.2–1.5 cm in diameter, white with pinkish or purplish-brown flushing ovoid, ca. 2.5 cm long, ca. 1.5 cm in diameter, glossy green subglobose, 1 cm long, 0.8 cm in diameter, outside bright pale green, inside as outside, but with pale pink flush ovoid, 1.2 cm long, 1 cm in diameter, light brown-green outside, brown or reddish-brown inside
Spathe limb oblong-elliptic, 4–4.5 cm long, 1.1–1.3 cm wide, green with brown mottling widely ovate in lower part, narrowly triangular in upper part, 12–26 cm long, 7.5–12 (–15) cm wide, dark brownish-purple narrowly ovate to lanceolate, 5.5–7 cm long, 1.2–2 cm wide, basally brownish, apically green orbicular, 2.7–3 cm long, 3 cm wide, whitish-greenish with a dense pinkish-brownish or brownish mottling triangular ovate, 7–14 cm long, 4–7.5 cm wide, dark green flushed with dirty brown narrowly triangular ovate, 7–9.5 cm long, 0.9–1.5 cm wide, bright pale green with brown longitudinal veins narrowly triangular ovate, 5–9 cm long, to 3 cm wide, light brown-green
Staminode slender filiform, decurved, yellowish-greenish unknown filiform, horizontally spread and slightly curved, yellow subulate, upper ones straight, lower ones variously curved, mostly downwards, pale yellow or cream subulate, upper ones straight, lower ones strongly curved downward, pale yellow cylindrical, mostly perpendicular to axis, creamy white cylindrical, spreading, dark yellow
Ovary obovoid, yellowish-greenish unknown ellipsoid, yellowish-greenish elongate, tapering to the base, basal half white, upper part spotted reddish-pink more or less ellipsoid, pale green elongate obovate, creamy white elongate, white
Stigma light yellow unknown yellow reddish-pink dirty whitish-greyish creamy white white
Distribution C. Vietnam S. Vietnam N. and Central India to Thailand C. Thailand N. Thailand Thailand Thailand, Myanmar, S. Vietnam

Key to the 24 presently known Vietnamese species of Typhonium

1 Sterile interstice of spadix entirely covered with staminodes T. flagelliforme
Only base of sterile interstice of spadix covered with staminodes 2
2 Leaves perfectly trifoliolate 3
Not as above 4
3 Plant with 3 leaves; appendix stipitate; female section of spadix with 5–6 rows of pistils T. thatsonense
Plant with 1 leaf; appendix sessile; female section of spadix with 2–3 rows of pistils T. hangiae
4 Inflorescence appearing before the leaves 5
Inflorescence appearing together with the leaves 6
5 Spathe 6–9 cm long; staminodes ca. 6 mm long T. penicillatum
Spathe 14–30 cm long; staminodes ≤ 3 mm long T. hayatae
6 Spathe limb elongate, narrowly lanceolate-triangular 7
Spathe limb wide, oblong-elliptic, ovate to lanceolate 15
7 Staminodes red with a light yellow acumen 8
Staminodes unicolourful 9
8 Spathe tube globose, to 1.5 cm long; staminodes 5 mm long, clavate T. bachmaense
Spathe tube oblong or cylindrical, 2 cm long; staminodes 12 mm long, acute T. kbangense
9 Spathe limb white T. praelongum
Not as above 10
10 Spathe limb corrugated T. corrugatum
Not as above 11
11 Leaf 3-lobed 12
Not as above 13
12 Stigma funnel-shaped and lobed T. stigmatilobatum
Stigma disciform and unlobed T. huense
13 Leaves with 7 leaflets, leaflets linear to or linear-lanceolate T. lineare
Not as above 14
14 Spathe limb much shorter than spadix appendix T. vermiforme
Spathe limb as long as spadix appendix T. dongnaiense
15 Spadix longer than spathe 16
Spadix as long as or shorter than spathe 18
16 Staminodes folded 180° apically T. phuocbinhense
Staminodes straight up to parallel to axis 17
17 Male zone cylindrical, staminodes cylindrical to conical T. khonkaenensis
Male zone subglobose, staminodes clavate T. acetosella
18 Leaves developing bulbils at the top and/or the base, upper surface ften grey variegated T. cordifolium
Not as above 19
19 Spathe limb very strongly circinnately recoiled over the entire length T. circinnatum
Not as above 20
20 Tuber producing rhizomatous offsets about 5 cm apart T. rhizomatosum
Not as above 21
21 Staminodes ≤ 3 mm long 22
Staminodes > 5 mm long 23
22 Spathe tube above the ground; spathe limb oblong-elliptic, with obtuse apex T. obtusum
Spathe tube underground; spathe limb triangular ovate, with acute apex T. vietnamense
23 Staminodes red with a light yellow acumen, upward straight or slightly curved T. blumei
Staminodes whitish, curly T. trilobatum

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statement

No ethical statement was reported.


This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 106.03-2020.37.

Author contributions

Conceptualization, Hong Truong Luu, Xuan Bach Nguyen-Le; Formal analysis, Hong Truong Luu, Nga Nguyen-Phi, Xuan Bach Nguyen-Le, Hong Thien Van; Funding acquisition, Hong Truong Luu; Investigation, Xuan Bach Nguyen-Le, Hieu Cuong Nguyen; Methodology, Hong Truong Luu, Nga Nguyen-Phi, Quoc Dat Nguyen, Quoc Dat Nguyen; Supervision, Hong Truong Luu; Visualization, Hong Truong Luu, Nga Nguyen-Phi, Xuan Bach Nguyen-Le; Writing – original draft, all authors; Writing – review & editing, Hong Truong Luu, Nga Nguyen-Phi, Xuan Bach Nguyen-Le. All authors have read and agreed to the published version of the manuscript.

Author ORCIDs

Hong Truong Luu

Nga Nguyen-Phi

Quoc Dat Nguyen

Hieu Cuong Nguyen

Hong Thien Van

Xuan Bach Nguyen-Le

Data availability

All of the data that support the findings of this study are available in the main text.


  • Boyce PC, Sookchaloem D, Hetterscheid WL, Gusman G, Jacobsen N, Idei T, Nguyen VD (2012) Araceae. Flora of Thailand 11: 101–321.
  • Bridson D, Forman L (1999) Herbarium Handbook (3rd Ed.). Lubrecht & Cramer Ltd, Kew, 346 pp.
  • Gagnepain F (1942a) Aracées. In: Lecomte H (Ed.) Flore Générale de l’Indo-Chine 6. Masson, Paris, 1174–1181.
  • Galloway A (2012) New Araceae species from Laos and Thailand. Aroideana 35: 51–64.
  • Hetterscheid W (2013) New Typhonium species from Asia. Aroideana 36: 93–97.
  • Hetterscheid WLA, Boyce PC (2000) A reclassification of Sauromatum Schott and new species of Typhonium Schott (Araceae). Aroideana 23: 48–55.
  • Hetterscheid WLA, Nguyen VD (2001) Three new species of Typhonium (Araceae) from Vietnam. Aroideana 24: 24–29.
  • Hetterscheid W, Sookchaloem D, Murata J (2001) Typhonium (Araceae) of Thailand: New species and a revised key. Aroideana 24: 30–55.
  • Hu SY (1968) Studies in the Flora of Thailand 41. Araceae. Dansk Botanisk Arkiv 23: 409–457.
  • King G, Prain D (1898) Descriptions of some new plants from the north-eastern frontiers of India. Journal of the Asiatic Society of Bengal 67: 284–305.
  • Low SL, Yu CC, Ooi IH, Eiadthong W, Galloway A, Zhou ZK, Xing YW (2021) Extensive Miocene speciation in and out of Indochina: The biogeographic history of Typhonium sensu stricto (Araceae) and its implication for the assembly of Indochina flora. Journal of Systematics and Evolution 59(3): 419–428.
  • Luu HT, Van HT, Ngo TTD, Nguyen LP, Le HP (2017) Typhonium thatsonense (Araceae), a new species from Vietnam. Novon 25(4): 438–441.
  • Murata J, Ohi-Toma T, Tanaka N (2010) New or noteworthy plant collections from Myanmar (4): Typhonium cordifolium and two new species, T. neogracile and T. praecox (Araceae). Shokubutsu Kenkyu Zasshi 85: 1–7.
  • Nguyen VD (2005) Araceae. In: Nguyen TB (Ed.) Checklist of Plant Species of Vietnam (Vol. 3). Agriculture Publishing House, Hanoi, 871–898.
  • Nguyen VD (2017) Flora of Vietnam 16: Araceae Juss. Publishing House for Science and Technology, Hanoi, 458 pp.
  • Nguyen VD, Croat TB (1997) A new species of Typhonium (Araceae) from Vietnam. Aroideana 20: 48–52.
  • Nguyen VD, Vu XP (2004) The genus Typhonium (Araceae) in flora of Vietnam. Academia Journal of Biology 26: 25–31.
  • Nguyen VD, Le CT, Nguyen VD, Ha MT, Nguyen TVA, Croat T (2021) Typhonium phuocbinhense sp. nov. (Araceae: Areae), a new species from central Vietnam. Phytotaxa 482: 073–079.
  • Nguyen VD, Le CT, Dinh QD, Nguyen TVA, Tran VT, Croat TB (2022a) Typhonium kbangense, a new species of Araceae (Aroidea–Areae) from Central Vietnam. Nordic Journal of Botany 2022(8): e03601.
  • Nguyen VD, Nguyen TVA, Tran VT, Le CT (2022b) Two new records of species and a new synonym of genus Typhonium (Araceae) for flora of Indochina. VNU Journal of Science: Natural Sciences and Technology 38: 54–60.
  • Pham TKT, Nguyen DD, Nguyen VC, Nguyen VD, Tran VT (2023) Typhonium hangiae (Araceae: Aroideae: Areae), a new species from Central Vietnam with a key to Vietnamese species of the genus. Kew Bulletin 78(4): 1–6.
  • Pham-Hoang H (1993) Cây cỏ Việt Nam [An illustrated flora of Vietnam]. Vol. 3. Montreal, Canada, 1176 pp.
  • Pham-Hoang H (2003) Cây cỏ Việt Nam [An illustrated flora of Vietnam]. Vol. 3. Youth Publishing House, Ho Chi Minh, 1020 pp.
  • Schott HW (1829) Wiener Zeitschrift für Kunst, Litteratur, Theater und Mode. Vienna.
  • Sriboonma D, Murata J, Iwatsuki K (1994) Revision of Typhonium (Araceae). Journal of the Faculty of Science, University of Tokyo Section III. Botany 15: 255–313.
  • Thiers B (2024) Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. [Accessed 31 January 2024]
  • Van HT, Nguyen-Phi N, Vu NL, Galloway A, Luu HT (2017) Typhonium dongnaiense (Araceae), a new species from Vietnam. Annales Botanici Fennici 54(4–6): 405–408.
  • Van HT, Van Son L, Nguyen-Phi N, Nguyen QD, Nguyen TQT, Nguyen HC, Luu HT (2021) A new species and a new record of Typhonium (Araceae) from southern Vietnam. Phytotaxa 527(3): 201–208.
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