www.mobot.org Research Home | Search | Contact | Site Map  
 
Research
W³TROPICOS
QUICK SEARCH

MO PROJECTS:
Africa
Asia/Pacific
Mesoamerica
North America
South America
General Taxonomy
Photo Essays
Training in Latin
  America

MO RESEARCH:
Wm. L. Brown Center
Bryology
GIS
Graduate Studies
Research Experiences
  for Undergraduates

Imaging Lab
Library
MBG Press
Publications
Climate Change
Catalog Fossil Plants
MO DATABASES:
W³MOST
Image Index
Rare Books
Angiosperm
  Phylogeny

Res Botanica
All Databases
INFORMATION:
What's New?
People at MO
Visitor's Guide
Herbarium
Jobs & Fellowships
Symposium
Research Links
Site Map
Search

Projects

Flora of the Venezuelan Guayana

<< Back

CLUSIACEAE

9. MAHUREA Aubl., Hist. Pl. Guiane 558, t. 222. 1775.

by Bruce K. Holst and Klaus Kubitzki

Shrubs or medium-sized trees; wood reddish; terminal buds with scales; indument simple. Leaves alternate, petiolate; blades with pinnate secondary veins connected by numerous subparallel tertiary veins; stipule-like colleters sometimes present. Inflorescences panicles or racemes. Flowers bisexual, pink, without scent. Sepals 5, quincuncial; petals 5, contorted. Stamens numerous, persisting after anthesis; filaments slender, connate at the base; anthers versatile, attached near base, elongate, 4-sporangiate, opening longitudinally, the connective broad and protruded into a cupulate subapical gland. Ovary glabrous, ovoid, 3-locular, each locule with 2 elongate placentas with numerous imbricate ovules; style simple; stigma 3-lobed. Capsule shortly stipitate, from the top septicidally dehiscent and leaving a subulate columella with thickened placentas, the valves woody, thickened, the septas thin. Seeds numerous, linear, sawdust-like; testa prolonged into a wing at the top and at the base; albumen sparing; embryo lateral, linear, terete.

Colombia, Venezuela, Guyana, French Guiana, Peru, northern Brazil; 2 species, 1 in Venezuela.

The second species, Mahurea palustris Aubl., occurs in coastal French Guiana and adjacent Brazil.

Mahurea exstipulata Benth., London J. Bot. 2: 365. 1843.

?Mahurea casiquiarensis Benth., J. Proc. Linn. Soc., Bot. 5: 64. 1861.

Shrub or medium-sized tree to 12(-20) m tall; flowers pink, showy. Colombia, Venezuela, Guyana, Suriname, French Guiana, Peru, Brazil (Amazonas); 2 subspecies, both in the flora area.

The type of Mahurea casiquiarensis Benth., Spruce 3161, is intermediate in some respects to the two subspecies recognized. Though M. exstipulata subsp. exstipulata is largely limited to Bolívar in the flora area, some transitional forms with subsp. duckei have been noted in scattered localities in Amazonas.

Key to the Subspecies of M. exstipulata

1. Leaves broadly lanceolate, obovate-spatulate, or oblong, ca. 2.4 times longer than broad; style thickened below stigma; Amazonas state ..... subsp. duckei

1. Leaves narrowly lanceolate, 3-5 times longer than wide; style not thickened below stigma; Bolívar state ..... subsp. exstipulata

M. exstipulata subsp. duckei (Huber) Kubitzki, Mem. New York Bot. Gard. 29: 138. 1978. -Mahurea duckei Huber, Bol. Mus. Goeldi Paraense Hist. Nat. Ethnogr. 7: 300. 1913.

Mahurea tomentosa Ducke, Arq. Inst. Biol. Veg. 1: 208. 1935.

Periodically flooded forests or nonflooded forests along rivers, 100-300 m; Amazonas (Río Cataniapo, Río Negro, upper Río Orinoco). Colombia, Guyana, Suriname, French Guiana, Peru, Brazil (Amazonas).

M. exstipulata subsp. exstipulata

Mahurea linguiformis Tul., Ann. Sci. Nat. Bot. sér 3, 8: 340. 1847.

Mahurea sororopantepuiana Steyerm., Fieldiana, Bot. 28: 395, fig. 81. 1952.

Evergreen lowland to montane and riparian forests, borders of periodically burned savannas, tepui slopes, low tepui summits, 100-1600(-2200) m; Bolívar (Gran Sabana, upper Río Cuyuní basin, Sororopán-tepui). Guyana, Brazil (Roraima). Fig. 217.

TOP

Scientific Comments:
Paul Berry (peberry@facstaff.wisc.edu) or Kay Yatskievych (kay.yatskievych@mobot.org).

 
 
© 1995-2024 Missouri Botanical Garden, All Rights Reserved
4344 Shaw Blvd.
St. Louis, MO 63110
(314) 577-5100

E-mail
Technical Support