Luzula excelsa Buchenau

  • Authority

    Balslev, Henrik. 1996. Juncaceae. Fl. Neotrop. Monogr. 68: 1-167. (Published by NYBG Press)

  • Family

    Juncaceae

  • Scientific Name

    Luzula excelsa Buchenau

  • Type

    Type. Bolivia. La Paz: Larecaja, nr. Sorata, Lancha de Cochipata, 2700-3200 m, Jan-Feb 1860, Mandon 1449 (lectotype, GOET!, here selected; isotypes, BM!, BR!, F!, G!, GH!, K!, NY!, P!, S!, US!, photo AAU!, QCA!).

  • Synonyms

    Luzula hieronymi Buchenau & Griseb., Juncodes hieronymi (Buchenau & Griseb.) Kuntze, Juncodes excelsum (Buchenau) Kuntze, Luzula hieronymi var. pusilla Castillon, Luzula hieronymi f. bonariensis Barros

  • Description

    Species Description - Perennial herbs, 40-100 cm high. Rhizome ascending or erect. Culms erect and apically nodding, terete, 1-4 mm diam. Basal leaves 3-20 to each culm, in rosette; sheaths short; blades linear, 15-20 x 0.5-2 cm, flat, margin pilose in young leaves. Cauline leaves resembling basal ones but with sheaths =7 cm long; the distal ones with shorter blades. Inflorescence a loosely branched panicle of nodding flower clusters, constituting 1/3-½ of the total plant height, divided into 3-6 parts by 5-20 cm long rachis segments; flower clusters cylindrical, ca. 0.5-1.5 x 0.5 cm. Proximal inflorescence bracts resembling cauline leaves, to 30 cm long, the distal ones progressively smaller. Bracteoles and uppermost bracts in the inflorescence linear to lanceolate, scariose, margin entire or divided into ciliate lobes. Tepals equal or subequal, 1.2-2.5 mm long, stramineous or rarely red-brown. Stamens 3, ca. 1 mm long; anthers oblong, ca. 0.4 mm long, shorter than the filaments. Capsule broadly oblong to obovoid, trigonous to 3-keeled, ca. 1.5 x 1.2 mm, light brown to reddish brown, glossy at dehiscence. Seeds ellipsoid, broadly apiculate, ca. 1 x 0.6 mm, smooth to rugose, outer seed coat hyaline, inner seed coat red-brown.

  • Discussion

    Luzula excelsa is related to L. ecuadoriensis; both have inflorescences with flowers congested in clusters which are arranged in a loose panicle divided by long rachis segments. The flowers of L. excelsa are smaller, <2.2 mm long, stramineous, and the flower clusters are usually so loosely arranged that the central branchlet in them is visible. Confusingly, some specimens are intermediate between L. excelsa and still another species, L. racemosa. This latter species is much less well defined where it is sympatric with L. excelsa than in areas of allopatry. This could indicate that hybridisation takes place between the two species.

  • Distribution

    Luzula excelsa is distributed in the Andes from Puno in Peru to Tucumán and Catamarca in Argentina. Within the neotropical region it has been collected at elevations of 16003500 m in sun-exposed places, rocky slopes, and road banks in the upper montane forest belt.

    Peru South America| Puno Peru South America| Bolivia South America| Cochabamba Bolivia South America| La Paz Bolivia South America| Tarija Bolivia South America|