Thismia, Griffith, 1845

Nuraliev, Maxim S., Yudina, Sophia V., Truong, Ba Vuong, Do, Thi Xuyen, Luu, Hong Truong, Kuznetsov, Andrey N. & Kuznetsova, Svetlana P., 2020, A revision of the family Thismiaceae (Dioscoreales) in Cambodia, Laos and Vietnam, Phytotaxa 441 (3), pp. 229-250 : 237-239

Thismia . javanica J.J. Smith (1910: 32 , Taf. 9, 10) ( Fig. 3 )

Literature:— Schlechter (1921: 36), Jonker (1938: 245, 1948: 23, Fig. 11), Larsen (1987: 125, Fig. 39-1), Pham-Hoang (2000: 759, Fig. 10808), Nguyen (2003: 27), Kumar et al. (2017: 232), Siti-Munirah & Dome (2019: 134, Fig. 7). Thismia arachnites auct., non Ridley (1905: 197): Chantanaorrapint (2018: 1, Fig. 2 ).

TYPE: —”Not preserved, from Java, Res. Batavia, Tjibeureum”, according to Jonker (1938: 246).

Description

Plant generally glabrous, branching by the formation of root suckers. Roots vermiform. Leaves several (up to 8 or probably more), scattered, up to 8.5 mm long. Flowers rarely terminal and solitary, usually in terminal monochasial inflorescence of up to 5 flowers. Terminal flowers surrounded by an involucre of (2)3 bracts; lateral flowers surrounded by an involucre of 2 transverse-adaxial bracts (floral prophylls). Plane of inflorescence branching transversal; monochasium type a bostryx. Involucral bracts (4)5.5–8(9.8) mm long. Pedicel (internode between involucral bracts and ovary) 1.2–1.4(2.6) mm long. Flower actinomorphic, 10.5–16 mm long from ovary base. Hypanthium obconic (urceolate), ca. 6–14 mm long (excluding inferior ovary), 6.5–9.5 mm wide in the upper part; involucral bracts reaching about one third or one half of hypanthium; outer hypanthium surface with 12 finely impressed longitudinal veins, verrucose-rugose, white to pale orange or light orange-red with 12 veins red or orange at least in the upper part; inner surface with longitudinal bars connected by numerous short transverse bars, fenestrated, colouration similar to that of the outer surface with bars sometimes contrasting with surrounding tissue. Annulus prominent, flat, almost circular to roundish-hexagonal, bright yellow or orange, 3.6–6.2 mm in diam., with circular orifice 1.9–3.3 mm in diam. Outer tepals spreading or reflexed down, ovate-triangular, 1–2.5(3.5) mm long, 2.2–3.9 mm wide at base, orange to red or yellow, translucent, margin entire, apex broadly obtuse or rounded. Inner tepals free, spreading, narrowly triangular, 1.5–3.3 mm long, 2.1–3.5 mm wide at base, orange to red or yellow and usually dark reddish towards apex, with entire translucent margin, with midvein strongly raised abaxially and continuing into a filiform appendage, with a minute triangular tip of tepal blade free from the appendage lying above the appendage base; appendages straight or arcuate upwards, (3.5) 4–30 mm long or probably longer, red to orange, often lighter towards apices. Stamens 2.5–4(5.5) mm long, with long supraconnectives, fused laterally along their entire length except for the filaments and the very tips to form a stamen tube. Supraconnective apex rectangular, with 3 teeth tapering into hairs 0.4–1 mm long. Supraconnectives bearing skirt-like appendages at the outer (adaxial) side slightly below thecae. Each appendage ca. as wide as supraconnective or wider, 1–2 mm wide, inclined towards the supraconnective apex and ± reaching it; main lamina of appendage widely attached to supraconnective tissue by lateral margins, triangular-trapezoid or quadrangular, erose along apical margin, at each lateral margin with a triangular projection inclined outside (towards hypanthium). Thecae adaxial (facing the hypanthium), separate, ca. 0.5–1 mm long. Androecial indumentum (apart from apical teeth) of stiff needle-like hairs at the margins of appendages and 2 rows of shorter glandular hairs on the sides of each theca. Interstaminal glands present. Stamens white or tinged with red or orange. Ovary outside not delimited from hypanthium, obconic or obovate, ca. 1–3.5 mm long, ca. 2.4–3.7 mm wide towards apex. Placentas column-like. Stylar column cylindrical, 1.5–2.8 mm long, 0.5–1 mm in diam., white; styles 2–3.5 mm below stamen apices, upright, simple, truncate, 0.7–1.5 mm long, bearing densely finely papillose stigmas, orange or white. Fruit ca. 6 mm long, orange or white; seeds ellipsoid.

Etymology: —The specific epithet “ javanica ” apparently refers to Java, where the type of this species was collected.

Phenology: —Flowering and fruiting from (December) April to October.

Additional specimens examined: — VIETNAM. Quang Tri Province: Huong Hoa District, Huong Phung Commune, Bac Huong Hoa Nature Reserve , Sa Mu mountain , 1012 m a.s.l., 11 October 2015, Do Thi Xuyen, Nguyen Tan Hieu BHH 800 ( HNU, MW) ; Khanh Hoa Province, Cam Lam District, Hon Ba Nature Reserve , N 12°07’33.58’’ E 108°57’19.99’’, 1300 m a.s.l., 21 June 2019, Truong Ba Vuong, Tu Bao Ngan, Mang Van Lam BV 426 ( MW) .

Distribution: — Vietnam: Quang Tri Province (Bac Huong Hoa Nature Reserve), Khanh Hoa Province (Hon Ba Nature Reserve); Thailand: Kanchanaburi Province (Sai Yok), Ranong Province (Khlong Na Kha); Malaysia (Terengganu); Indonesia (Sumatra, Java). Additionally, specimens from Chantaburi Province (Krathing waterfall and Khao Chamao National Park) and Satun Province (Thale Ban and Tarutao National Parks) of Thailand assigned to Thismia arachnites by Chantanaorrapint (2018) most likely belong to this species. A single specimen of T. javanica from Myanmar cited by Shepeleva et al. (2020) probably belongs to this species, but its identification is to be verified by careful morphological investigation.

Notes: —1. Chantanaorrapint (2018) identified several specimens of Thismia collected in Eastern and Peninsular Thailand as T. arachnites , a species that has been known for a long time only from a type collection made in Peninsular Malaysia. As Chantanaorrapint (2018) noted, the Thai specimens differ from the protologue of T. arachnites as well as from Ridley’s illustration selected as a lectotype in the structure of stamen apex. According to Ridley (1905: 197), the stamen apex of T. arachnites bears “numerous small teeth”, and 5–6 of them are depicted in the lectotype. The Thai specimens, in contrast, are uniformly characterised by “3-toothed stamens with each tooth bearing a distinct stiff hair” ( Chantanaorrapint 2018). Chantanaorrapint (2018: 3) concluded that the difference is a result of Ridley’s misobservation “due to the resolution of Ridley’s microscope”. However, the Thai specimens in fact show exactly the same stamen structure as that of T. javanica ( Jonker 1938, 1948, Larsen 1987, Siti-Munirah & Dome 2019). Since T. javanica has already been known from Thailand and shows the same stamen morphology, it made sense to evaluate the possibility of attribution of the specimens cited by Chantanaorrapint (2018) to T. javanica . However, T. javanica is not mentioned in the latter paper by an unknown reason. As we can judge from the detailed description and illustrations provided by Chantanaorrapint (2018), the specimens in question can tentatively be identified as T. javanica , which is known to be quite variable with respect to flower colouration and length of appendages of inner tepals. Additionally, at least one of the specimens studied by Chantanaorrapint (2018) shows remarkably long styles, a feature not reported before for either T. javanica or T. arachnites . Finally, the stamens with numerous small teeth at apex were described not only for T. arachnites , but also for T. brunonis (Griffith 1845) , which indicates that such a condition is indeed present in certain Thismia species, and there is no reason to treat Ridley’s description as erroneous.

2. Although Pham-Hoang (2000) was the first to list Thismia javanica for the flora of Vietnam, he has not cited any specimen confirming its occurrence. Until now, the presence of this species in Vietnam remained highly questionable for the reason of external similarity of T. javanica with T. tentaculata ( Larsen & Averyanov 2007) . Here, we report the finding of T. javanica in Vietnam based on thorough specimen identification for the first time.

3. The flowers and their parts are generally smaller in the specimen from Hon Ba Nature Reserve (Truong Ba Vuong et al. BV426) than in the other specimen investigated here (Do Thi Xuyen et al. BHH 800). Besides, the specimen BV426 is similar in its external appearance to the atypical specimens of T. tentaculata collected in the same location (see note under the latter species). However, the specimen BV426 differs from them by a distinctly tridentate stamen apex (with equal teeth), which is one of the main features distinguishing T. javanica from T. tentaculata . This is consistent with reddish hypanthium and presence of transverse bars on the inner surface of hypanthium in this specimen.

Figures

FIGURE 2. Thismia annamensis. A–D. Nuraliev 1562; E–G. Nuraliev 999. H. Nguyen Quoc Dat et al. Pl_Q.NG 0025; all photos by M. Nuraliev except for H by Nguyen Quoc Dat. A. Habit. B, E. Flower, apical view. C. Annulus and stamens, lateral view. D. Flower, longitudinal section. F. Flower with a longitudinal half of hypanthium removed, oblique-bottom view. G. Longitudinal section of distal part of flower showing stamen structure. H. Styles, apical view.

FIGURE 3. Thismia javanica. A–D. Do Thi Xuyen et al. BHH 800, photos by Do Thi Xuyen and SEM image by S. Yudina; E–I. Truong Ba Vuong et al. BV426, photos by Truong Ba Vuong. A, E. Flower, apical view. B, F. Flower, lateral view. C. Longitudinally opened and flattened hypanthium showing stamens. D. Supraconnective, abaxial view (SEM). G. Flower, oblique view. H. Flower with longitudinally opened hypanthium (three stamens removed). I, Three stamens, adaxial view.