Wednesday, June 10, 2020

[Botany • 2020] Winitia thailandana • Generic Status of Winitia (Annonaceae, Miliuseae) Reaffirmed by Molecular Phylogenetic Analysis, Including A New Species and A New Combination from Thailand

แสดทักษิณา Winitia thailandana Chaowasku & Aongyong

in Chaowasku, Aongyong, Damthongdee, et al., 2020.
DOI: 10.5852/ejt.2020.659

The generic status of Winitia Chaowasku (Annonaceae Juss., Miliuseae Hook.f. & Thomson) is reaffirmed by an extensive phylogenetic reconstruction using seven plastome regions (matK, ndhF, rbcL, ycf1 exons; trnL intron; psbA-trnH, trnL-trnF intergenic spacers) and including, among others, seven accessions of Winitia plus two accessions of its sister group, Stelechocarpus Hook.f. & Thomson. The results disclosed a maximally supported clade of Winitia, as well as of Stelechocarpus. The sister relationship of the two genera is still rather poorly supported and the branch uniting them is very short, whereas the branches leading to Winitia and to Stelechocarpus are relatively long, corresponding to their considerable morphological differences. Additionally, in Miliuseae there is a particular indel of eight continuous base pairs in the trnL-trnF intergenic spacer potentially diagnostic for generic discrimination, i.e., members in the same genus possess the same indel structure (absence or presence of a gap), and this indel differentiates Winitia from StelechocarpusWinitia cauliflora (Scheff.) Chaowasku appears polyphyletic and Winitia longipes (Craib) Chaowasku & Aongyong comb. nov. based on Stelechocarpus longipes Craib is consequently proposed. Furthermore, our phylogenetic data support a new species, Winitia thailandana Chaowasku & Aongyong sp. nov. from southern Thailand, which is described and illustrated. A key to genera in the sageraeoid clade (Sageraea-Winitia-Stelechocarpus) and a key to the four species of Winitia are provided.

Keywords: identification key; Malmeoideae; phylogenetics; systematics; taxonomy

Order Magnoliales Juss. ex Bercht. & J.Presl
Family Annonaceae Juss., nom. cons.
Tribe Miliuseae Hook.f. & Thomson

Genus Winitia Chaowasku

Winitia longipes (Craib) Chaowasku & Aongyong comb. nov.

Stelechocarpus longipes Craib, The Journal of the Natural History Society of Siam 6: 43 (Craib 1923). 
Type: THAILAND · Khao Rum [Nakhon Si Thammarat Prov.]; fl; Native Collector s.n. (Herb. Eryl Smith 643); holotype: K[K000382080]; isotype: BK.

(A-B) Flowers of Winitia thailandana Chaowasku & Aongyong sp. nov.  Flower.

(lower) Flowers of Winitia cauliflora (Scheff.) Chaowasku and 
Winitia longipes (Craib) Chaowasku & Aongyong comb. nov.  

Fig. 4. Flowers and floral organs of Winitia thailandana Chaowasku & Aongyong sp. nov.
A–B. Flower. C. Flower with petals removed. D. Stamen, abaxial (above) and adaxial (below) sides. E. Back side of flower, showing sepals (abaxial side). 
A, B from Gardner & Sidisunthorn ST0817 (L), photographs by S. Gardner; C–E from Aongyong 9 (CMUB).

Winitia thailandana Chaowasku & Aongyong sp. nov. 

Diagnosis: Morphologically similar to Winitia expansa, differs by having a non-glaucous appearance on the petal adaxial surface (glaucous in W. expansa) and shallow pits on the adaxial surface of the inner petals (no pitted structures in W. expansa). Moreover, its inflorescences are mostly clustered on large roots and at the unswollen base of trunks, whereas the inflorescences of W. expansa are mostly clustered at the swollen base of trunks. 

Etymology: Named after Thailand, a country where this species is endemic. 


Tanawat Chaowasku, Kithisak Aongyong, Anissara Damthongdee, Hathaichanok Jongsook and David M. Johnson. 2020. Generic Status of Winitia (Annonaceae, Miliuseae) Reaffirmed by Molecular Phylogenetic Analysis, Including A New Species and A New Combination from Thailand. European Journal of Taxonomy. 659; 1–23. DOI: 10.5852/ejt.2020.659


แสดทักษิณา Winitia thailandana Chaowasku & Aongyong พืชชนิดใหม่ของโลก พบที่เขาหินปูนจังหวัดสุราษฎร์ธานีเท่านั้น ดอกมีความคล้ายชมพูภิรมย์ Winitia expansa Chaowasku ซึ่งพบที่จังหวัดพัทลุง นอกจากนี้ยังพบว่างำเงาะจากประเทศไทย แตกต่างจากตัวอย่างต้นแบบของชื่อ Winitia cauliflora จึงได้ชื่อใหม่ว่า Winitia longipes (Craib) Chaowasku & Aongyong ซึ่งย้ายมาจากสกุล Stelechocarpus