Brachyotum ledifolium (Desr.) Triana

  • Authority

    Wurdack, John J. 1953. A revision of the genus Brachyotum (Tibouchineae-Melastomataceae). Mem. New York Bot. Gard. 8 (4): 343-407.

  • Family

    Melastomataceae

  • Scientific Name

    Brachyotum ledifolium (Desr.) Triana

  • Description

    Species Description - Trichomes notably shaggy-plumulose. Branchlets rounded-quadrangular, densely to moderately and rather persistently loose-strigulose. Petiole (2-)4-7 mm. Blade (9-)15-25(-40)x (5-)7-12(-15) mm., elliptic to ovate with the apex acute to obtuse and the base obtuse to subtruncate, the 3 primaries narrowly impressed above and elevated below, the 10-15 pairs of secondaries obscurely impressed above and elevated below; above sparsely to densely short-strigulose to short-strigose, the hairs 1-20/mm.2 and 1/5-1/3 adherent with their bases not markedly expanded; below densely to very densely hirsutulous, the hairs (10-)30-60/mm.2 and of varying lengths with the very numerous shorter ones appearing almost stellate due to much-contracted axes, giving a sparkling appearance to the surface (sub lente), the glands solitary and 20-30/mm.2 but obscured by the hairs. Flowers 5-merous (very rarely a few 4-merous), mostly solitary on short bi-bracteolate pedicels in opposite upper leaf axils, rarely the terminal ones ternate with the peduncle not differentiated, or solitary and terminal. Pedicel 4-9 mm. below the bracteoles, 1-5 mm. above; pedicellar bracteoles 3.5-5 x 2-4 mm., rarely leaflike to 11 x 6 mm., elliptic, above glabrous or apically strigulose, below as the leaves, early caducous or persistent until just after anthesis. Hypanthium 4-8 x 4-6 mm., 0.4-0.7 mm. thick medianly, very densely strigulose to short-strigose 15-30/mm.2 Sepals (4-)5-7 x 3-4.5 mm., ovate-oblong with the apices obtuse to rounded, united at bases 0.4-1.2 mm., the sinuses narrowly acute or rounded, sometimes with a few longer sinal hairs to 1-2 mm. Petals pale yellow, 9-17 x 9-15 mm., asymmetrically obovate with the apices obliquely truncate to very broadly obtuse, the cilia 0.1-0.5 mm. (terminally to 0.6-1 mm.) and non-glandular (rarely a few of the basal cilia with early-caducous glandular tips). Filaments 5-9.5 mm.; anthers 4-9 mm.; connective at anther base 0.5-0.8 mm. wide but almost always not at all prolonged nor free of the anther. Style 17-25 x 0.5-0.8 mm., exserted 2-8 mm. Ovary 5-7.5 x 3-4.5 mm., sparsely strigulose on the apical 1.5-3 mm., the apical lobes 0.5-1.5 mm. above the locules.

    Distribution and Ecology - Distribution: central Colombia to central Ecuador, alt. 2600-4200 m.

  • Discussion

    Melastoma ledifolia Desr. in Lam. Encyc. 4: 48. 1796.

    Rhexia canescens Bonpl. Rhexies 14. 1806-1808.

    Chaetogastra canescens (Bonpl.) DC. Prodr. 3: 134. 1828. Non sensu Naudin, Ann. Sci. Nat. III. 14: 135. 1850.

    Pleroma ledifolium (Desr.) DC. Prodr. 3: 151. 1828.

    Alifana canescens (Bonpl.) Raf. Syl. Tell. 101. 1838.

    " PLasiandra ledifolia" (Bonpl.) Naudin, Ann. Sci. Nat. III. 13: 159. 1849.

    Chaetogastra sulphurea Naudin, Ann. Sci. Nat. III. 14: 135. 1850.

    Chaetogastra bonplandiana Naudin, Ann. Sci. Nat. III. 14: 137. 1850.

    Brachyotum canescens (Bonpl.) Triana, Trans. Linn. Soc. 28: 48. 1871.

    Brachyotum sulphureum Triana, Trans. Linn. Soc. 28: 166. 1871. (?) Nomen nudum.

    Type Collection and Locality: / . de Jussieu s.n. (HOLOTYPE presumably in Herb, de Jussieu at P). Since de Jussieu began his Andean collecting in northern Ecuador and visited Quito, the type locality is probably somewhere in this area, perhaps the slopes of Pichincha which are readily accessible from Quito and from which subsequently have been collected many specimens which duplicate the type photograph.

    Type Photographs and Illustrations: F36131 (presumed holotype); F36136 (presumed holotype of Rhexia canescens at P); F3613O (presumed holotype of Chaetogastra sulpburea at P);F36l29 (presumed holotype of Chaetogastra bonplandiana at P); Rhexies pi. 6, not pi. 28(1806-1808) (as Rhexia canescens); Ann. Sci. Nat. III. 14: pi. 4, f. 6 (as Chaetogastra bonplandiana); Trans. Linn. Soc. 28: pi. 3, f. 33e (as Brachyotum sulphureum. The assignment of this name and drawing to B. ledifolium is questionable,since the flower shown is 4-merous and the anthers minutely tuberculate.)

    Vernacular Names: Sarzilejo (Bonpl. Rhexies); Puca Chaglla (Steyermark 52348); Illinche (Acosta 8737); Pucafichana (Acosta 8062); Rumbra (Acosta 7533); Zarzillejo (Dryander 2715); Puka-shakia (Quito, Lebmann 6377).

    One of the several Bonpland sheets seen from Paris was labeled "Loxa," but this sheet seems to be part of the same collection as the Bonpland Purace specimens. The herb. Ventenat specimen (G-DEL) is probably an isotype of Melastoma ledifolia, since the sheet, according to the label, was given to Ventenat by Lamarck in whose publication Desrousseaux's description appeared. The herb. Ruiz & Pavon specimen (F) was probably collected by Tafalla in Ecuador.

    From the type photograph of Melastoma ledifolia, which indicates that A. L. de Jussieu's herbarium was not given to Paris until 1857, and from Naudin's questioning the transfer of this species to Lasiandra, it is evident that Naudin had not seen the J. de Jussieu holotype of this species; if he had seen this collection, the Jameson collection upon which Chaetogastra sulphurea was based would likely have been placed under Desrousseaux's species. The isotype of Chaetogastra rostrata (F38256) in the Jussieu herbarium also was not annotated by Naudin, although he described that species from another sheet of the same Dombey collection at Paris.

    In Wiggins 11027, Acosta 7534, and Haught 2947, the ventral lobes of the connective are free of the anther 0.1-0.5 mm., but otherwise these collections agree perfectly with the vast majority of other collections. No demarcation can be made between specimens with the leaves smaller and more generally ovate and the upper leaf surface densely pubescent (many Colombian collections) and those with larger elliptic leaves and the upper leaf surface sparsely strigulose (many Pichincha collections); every modification between these two mild extremes exists. Rhexia canescens and Chaetogastra bonplandiana generally belong to the former category, Melastoma ledifolia and Chaetogastra sulphurea to the latter. Lagerheira (1899) noted the variability of these characters in various ecologic niches on the slopes of Pichincha.

    In addition to B. gleasonii, B. ledifolium seems to be also related to B. radula and B. maximowiczii; these Peruvian species differ in the petal color and shape, the connective prolongation, the strictly appressed pubescence on stems and lower leaf surface primaries, and the much broader-based trichomes on the upper leaf surface.