Monday, February 8, 2021

[Botany • 2021] Curcuma lithophila & C. rufostriata (Zingiberaceae) • Two New Species from Thailand, and Additional Notes on C. papilionacea

 Curcuma lithophila Škorničk. & Soonthornk.

in Soonthornkalump, Pungpairote, Niwesrat & Skornickova, 2021.

Curcuma lithophila and C. rufostriata, two new species from Curcuma subgen. Hitcheniopsis, are described and illustrated. They are compared with their morphologically closest species, Curcuma rhabdota, C. papilionacea and C. sparganiifolia. Notes on distribution, ecology, etymology, uses and IUCN provisional assessments are provided. Further notes on the distribution of the recently described C. papilionacea and an improved IUCN conservation assessment are reported from additional collections.

Keywords: Curcuma rhabdota, Curcuma papilionacea, Curcuma subgen. Hitcheniopsis


Figure 1.  Curcuma lithophila Škorničk. & Soonthornk.,
A–B. Typical habitat in Kanchanaburi Province, Ta Sao Subdistrict; C–D. Plant habit; E. Infructescence with almost ripe fruits; F. Infructescence with one capsule dehisced; G. Old inflorescence in side view.
Photographed by: S. Niwesrat.

Figure 2.  Curcuma lithophila Škorničk. & Soonthornk.
A. Typical habitat in Kanchanaburi Province, Wang Po Subdistrict; B. Plant habit; C. Detail of inflorescence in side view; D. Entire plant (scale 15 cm), E–F. Inflorescence with flower in front view (note the colour and shape variability); G. Almost ripe fruits and seeds. H. Flower dissection, from left: bracteole, calyx, floral tube (longitu-dinally dissected), ovary, lateral staminodes with dorsal lobe in between (upper part), lateral lobes with labellum in between (lower part) and stamen in the centre (inset detail of stamen from front, side and back view).
Scale bars: D. = 10 cm; G. = 5 mm; H. = 10 mm. 
Photographed by: A–C, E, F from type locality by T. Puangpairaote; D, G, H by S. Soonthornkalump.

Curcuma lithophila Škorničk. & Soonthornk., sp. nov. 
(subgen. Hitcheniopsis)

Similar to Curcuma rhabdota Sirirugsa & M.F.Newman in overall habit, colour of the flowers,and spurless anther but differs in the lack of comabracts, bracts without prominent red-brown striation,and lateral staminodes broadly obovate and broaderthan the labellum (versus prominent coma bracts, bracts with prominent striation and lateral staminodeselliptic and much narrower than the labellum in C. rhabdota). 
Type: Thailand. Kanchanaburi Province, Sai Yok District, Lum Sum Subdistrict, alt. 214 m, 19 Aug. 2020, Puangpairote TP-1150 (holotype BKF!;isotypes E!, PSU!, QBG!, SING!). Figs. 1 & 2.

Etymology.— Greek, litho-, stone and -philus, loving; referring to the rocky habitat preferred by this species.

Figure 3. Curcuma rufostriata Škorničk. & Soonthornk.
A. Typical habitat in Prachinburi Province; B–D. Plants in the habitat; E. Plant habit; F. Detail of rhizome (inset: ligules).
 Scale bars: E. = 15 cm; F. = 2 cm. 
Photographed by: A–D from A. Rodphitak; E, F from S. Soonthornkalump.

Figure 4. Curcuma rufostriata Škorničk. & Soonthornk.
A. Examples of variability in inflorescence shape and colouration; B. Almost mature fruit; C. Flower (front view); D. Flower in bract (side view); E. Seeds; F. Stamens (front, side and back view); G. Flower in side view (bracteole attached), bracteole, calyx, ovary with floral tube (tube longitudinally opened into two halves) flower parts: stamen (central), lateral staminodes with dorsal corolla in between (upper half), lateral corolla lobes with labellum in between (lower half);
Scale bars: E. = 3 mm; F. = 5 mm; G. = 10 mm. 
Photographed by: A, B, E–G from type by S. Soonthornkalump; C, D by A. Rodphitak.

Curcuma rufostriata Škorničk. & Soonthornk., sp. nov.
(subgen. Hitcheniopsis)

Similar to Curcuma rhabdota Sirirugsa & M.F.Newman in fertile bracts with reddish brown striation and pink spots on each side of the apex, and overall shape and colour of the flowers, but differs in the lack of coma bracts, L-shaped anther with prominent anther spurs and coriaceous laminae without prominent plication (versus prominent coma bracts, spurless anthers and non-coriaceous plicate laminae in C. rhabdota).
 Type: Thailand. Prachinburi Province, Mueang District, Noen Hom Subdistrict, alt. 126 m, 11 June 2020, Soonthornkalump Sutt-216 (holotype BKF!; isotypes BK!, E!, K!, P!, PSU!, QBG!, SING!). 

Etymology.— Latin, rufus-, reddish brown and -striatus, striate; referring to the linear markings on the fertile bracts.

Sutthinut Soonthornkalump, Tidarat Pungpairote, Sira Niwesrat and Jana Skornickova. 2021. Curcuma lithophila and C. rufostriata (Zingiberaceae), Two New Species from Thailand, and Additional Notes on C. papilionacea Thai Forest Bulletin (Botany). 49(1); 32-43. DOI: 10.20531/tfb.2021.49.1.03