Chassalia blumeana Govaerts, 2008

Yu, Tian Yi, Turner, Ian M. & Cheek, Martin, 2021, Revision of Chassalia (Rubiaceae-Rubioideae-Palicoureeae) in Borneo, with 14 new species, European Journal of Taxonomy 738, pp. 1-60 : 15-16

Chassalia blumeana Govaerts

Botanical Journal of the Linnean Society 157: 119 ( Ruhsam et al. 2008).

Replaced synonym:

Cephaelis stipulacea Blume, Bijdragen tot de flora van Nederlandsch Indië (16): 1005 ( Blume 1826 –1827). – Uragoga stipulacea (Blume) K.Schum. in Engler & Prantl, Die natürlichen Pflanzenfamilien 4 (4–5): 120 ( Schumann 1891). – Uragoga blumeana Kuntze, Revisio generum plantarum 2: 955 ( Kuntze 1891a), nom. illegit. (superfl.). – Chassalia stipulacea (Blume) Piessch. , Flora 196: 128 ( Piesschaert et al. 2001), nom. illegit., non Chassalia stipulacea DC. , Prodromus Systematis Naturalis Regni Vegetabilis 4: 532 (1830) ( Candolle 1830). – Type: JAVA • C.L. Blume s.n.; hololectotype: L[L 0057738], designated by Turner (2019: 397).

Description

Shrub to small tree, height unknown. Stem terete, canaliculate with 2 longitudinal grooves when dry. Internodes 1.5–3.5 cm long. Stipule flabellate, 4–5 × 6–8 mm, Leaf-blades obovate to elliptic, 27–29 × 8.5–9 cm, apex acuminate, acumen 1–1.5 cm, base truncate, slightly decurrent to petiole, midrib slightly raised at adaxial and abaxial, secondary nerves 12 from each side of the midrib. Petioles 2.5–3.5 cm long, 1.5–2 mm wide. Inflorescence / flowers not seen. Infructescence one per stem, compound cyme with 3 capitula appearing as one head, 4 cm long, peduncle 3 × 0.3 mm, branches and rachis 2–4 mm long, bracts of rachis and branches 2, ovate, 0.5 × 0.4 mm, bracts of capitulum ovate with a chaffy edge, 4–5 × 5 mm. Pedicel of fruit 3–5 mm long. Fruit ellipsoid to ovoid, 8–11 × 5–7 × 5 mm, calyx persistent, not accrescent, 3 × 1 mm, disc persistent, not accrescent, 0.8 × 0.8 mm, fruit surface convex, with two adjacent parallel longitudinal crests 0.4 mm wide, 0.6 mm apart along their length, forming a longitudinal groove from apex to base between the two crests. Pyrene not seen.

Distribution, habitat

Java ( Indonesia) and Borneo ( Brunei). Lowland evergreen forest.

Remarks

The lectotype specimen of Chassalia blumeana [L 0057738] was collected in Java. The infructescence of the lectotype specimen is a 3-branched compound cyme with branches and rachis 2–4 mm long. The branches and rachis remain short during fruit maturation. The exact distribution of this species in Borneo

is unknown. The specimen most similar to the lectotype found in Borneo from the Kew herbarium is: BRUNEI • Bang Dangung, Bila pinggan group; 12 Jul. 1993; Jay H. Bernstein JHB 405; K!.

Chassalia blumeana differs from other species by the base of the inflorescence peduncle not having bracts, and by having the branches and rachis of the infructescence less than 5 mm long. It differs from Chassalia ramosa T.Y.Yu sp. nov. by having just 1 flowering branch, rather than two or more per stem.

Chassalia blumeana may be the taxonomically most difficult species among all Asian species of Chassalia . Most of the specimens of Chassalia from Borneo were previously identified as Cephaelis psychotrioides (= Chassalia psychotriformis ) and Cephaelis stipulacea (synonym of Chassalia blumeana ). These specimens contain a wide range of morphological variation. The lectotype specimen of Chassalia blumeana from Java shows that this species seems to have 1 peduncle and 3 capitula on highly reduced partial peduncles less than 0.5 cm long. This makes the inflorescence look as though it is one big capitulum. The description in the protologue indicates that this species is distributed from West to Central Java ( Blume 1826 –1827). Additional information is provided by the description and illustration of Valeton (1913a). These highlight the short partial peduncles (5–10 mm long) which are slightly longer then the partial peduncle of the lectotype specimen. Valeton (1913a) recorded it as distributed from Java and in Borneo from northwest Indonesian Borneo to southwest Malaysian Borneo (Kuching). In this survey, specimens which appear to be a reasonable match for the type specimen of C. blumeana have been found in both Indonesian Borneo and Malaysian Borneo (Kuching), as well as Brunei. However, several specimens from west Sarawak to Sabah seem to share similarity with the typical C. blumeana but also vary somewhat from this species. Therefore, the delimitation of C. blumeana with similar specimens from Borneo still needs further study.