Morphological, anatomical, and taxonomic studies in Anomochloa and Streptochaeta (Poaceae, Bambusoideae)

Related Titles

Series: Smithsonian contributions to botany, no. 68

By

Judziewicz, Emmet J
Soderstrom, Thomas R.

Type

Book

Material

Published material

Publication info

Washington, D.C, Smithsonian Institution Press, 1989

Notes

Although resembling the core group of the bambusoid grasses in many features of leaf anatomy, the Neotropical rainforest grass genera Anomochloa and Streptochaeta share characters that are unusual in the subfamily: lack of ligules, exceptionally long microhairs with an unusual morphology, a distinctive leaf blade midrib structure, and 5-nerved coleoptiles. Both genera also possess inflorescences that are difficult to interpret in conventional agrostological terms. Anomochloa is monotypic, and A. marantoidea, described in 1851 by Adolphe Brongniart from cultivated material of uncertain provenance, was rediscovered in 1976 in the wet forests of coastal Bahia, Brazil. The inflorescence terminates in a spikelet and bears along its rachis several scorpioid cyme-like partial inflorescences. Each axis of a partial inflorescence is subtended by a keeled bract and bears as its first appendages two tiny, unvascularized bracteoles attached at slightly different levels. The spikelets are composed of an axis that bears two bracts and terminates in a flower. The lower, chlorophyllous, deciduous spikelet bract is separated from the coriaceous, persistent, corniculate upper bract by a cylindrical, indurate internode. The flower consists of a low membrane surmounted by a dense ring of brown cilia (perigonate annulus) surrounding the andrecium of four stamens, and an ovary bearing a single hispid stigma. Other peculiarities of A. marantoidea include its hollow leaf sheaths and long, hollow, bipulvinate pseudopetioles and chromosome number of n = 18. The caryopsis and embryo are large, but their structure is typically bambusoid. Streptochaeta consists of three species and one subspecies (S. spicata subsp. ecuatoriana, newly described here) and conforms to the bambusoid core group in seedling morphology and leaf anatomy. Streptochaeta and Anomochloa are quite divergent but may be more closely related to each other than to any other grass. They share features that indicate affinities with the Olyreae.

Subjects

Anomochloa , Streptochaeta

Call Number

QK1 .S2747 no. 68

Language

English

Identifiers

DOI: https://doi.org/10.5962/bhl.title.131652
GPO: 910-E
LCCN: https://lccn.loc.gov/88600187
OCLC: 18050339
Wikidata: https://www.wikidata.org/entity/Q51406768