Typhonium in Flora of China @ efloras.org

18. Typhonium Schott, Wiener Z. Kunst. 1829: 732. 1829.

犁头尖属 li tou jian shu

Authors: Heng Li & Wilbert L. A. Hetterscheid

Herbs, seasonally dormant. Underground part a long or short tuberous rhizome. Leaves entire, sagittate-hastate, 3-lobed or -partite. Inflorescence simultaneous with or preceding leaves; peduncle short or long. Spathe divided into a strongly convolute basal part with a ± strong apical constriction and a spreading lanceolate to ovate-triangular limb. Spadix as long as or longer than spathe, with 4 zones: a proximal female zone, an intermediate sterile zone with staminodes all over (in Typhonium flagelliforme only) or only at base, a male zone, and a sessile or stipitate appendix. Female flowers 1-loculed with 1 or 2(or 3) orthotropous basal ovules. Staminodes variable, spatulate to filamentous or variously reduced. Male flowers with 1-3 stamens opening by slits or pores; connective sometimes prolonged. Fruiting zone with spathe remaining (sometimes splitting open at maturity); berries ovoid, 1(or 2)-seeded. Seeds with endosperm.

About 50 species: from India to Polynesia; distributions in Africa and the West Indies are the result of human introductions; nine species (four endemic) in China.

The number of species given here for China is expected to be a considerable underestimation in view of the high species numbers in N Thailand and N Vietnam.

Recent molecular investigation of the tribe Areae (Cusimano et al, Taxon 59: 439-447. 2010) suggested that Typhonium sensu Hetterscheid and Boyce (Aroideana 23: 48-55. 2000) is polyphyletic and transferred several species to Sauromatum. The latter genus in its new monophyletic circumscription was shown not to be the direct sister genus to Typhonium sensu stricto.

1 Sterile zone between female and male zone fully covered by staminodes. 4 T. flagelliforme

+ Sterile zone between female and male zone with basal staminodes only, rest naked (2)

2 (1) Staminodes vermiform, thin, long, irregularly curving and twisting in all directions (3)

+ Staminodes different, when filiform then not curving in all directions (4)

3 (2) Staminodes numerous, proximal ones covering most of female zone; spathe limb broadly triangular; underground part a short, tuberous rhizome. 9 T. trilobatum

+ Staminodes few, female zone readily visible; spathe limb lanceolate; underground part a long, cylindric rhizome. 5 T. hunanense

4 (2) Spathe limb broadly triangular, or basal part triangular and apical part lanceolate, purple (5)

+ Spathe limb lanceolate, pale purple or ± cream-colored (7)

5 (4) Basal part of spathe limb triangular, apical part narrowed, lanceolate; leaf entire and linear, or deeply 3-lobed, lobes linear. 8 T. trifoliatum

+ Spathe limb broadly triangular, not narrowed to apex; leaf entire and triangular to triangular-hastate or triangular-sagittate, or ± deeply 3-lobed, lobes ovate or ovate-lanceolate (6)

6 (5) Staminodes downcurved. 7 T. roxburghii

+ Staminodes upcurved. 3 T. blumei

7 (4) Staminodal flowers present just below base of appendix, a naked axis part between these and male zone, staminodes above female flowers 3-4 mm. 2 T. baoshanense

+ Staminodal flowers absent above male flowers (8)

8 (7) Staminodes few, all vertical, parallel to spadix axis, 3-4 mm. 1 T. albidinervium

+ Staminodes numerous, at least partly oblique or horizontally spreading, 6-7 mm. 6 T. jinpingense

Lower Taxa

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