Stenogonum

Nuttall

Proc. Acad. Nat. Sci. Philadelphia 4: 19. 1848

Common names: Two-whorl buckwheat
Etymology: Greek stenos, narrow, and gonos, seed, alluding to achene
Synonyms: Eriogonum sect. Stenogonum (Nuttall) Kuntze
Treatment appears in FNA Volume 5. Treatment on page 431. Mentioned on page 220, 433.
Herbs, annual; taproot slender. Stems arising directly from the root, spreading to decumbent, solid, not fistulose or disarticulating into ringlike segments, glabrous or minutely strigose or glandular. Leaves usually persistent through anthesis, basal and rosulate or basal and cauline, alternate; petiole present (basal leaves); blade narrowly lanceolate to oblanceolate or spatulate to orbiculate, margins entire. Inflorescences terminal, cymose; branches mostly dichotomous, not brittle or disarticulating into segments, round, minutely strigose or glandular, glabrous; bracts 3 per node, connate basally, scalelike, triangular, not awn-tipped, glabrous or sparsely glandular. Peduncles straight or flexed, slender to filiform, sometimes absent. Involucral bracts in 2 whorls of 3, connate proximally, lanceolate, not awn-tipped. Flowers (6–)9–15 per involucral cluster at any single time during full anthesis; perianth yellow to reddish yellow, broadly campanulate when open, narrowly urceolate when closed, pilose abaxially; tepals 6, monomorphic, entire apically; stamens 9; filaments basally adnate, glabrous; anthers yellow, oval. Achenes usually included, light brown, not winged, 3-gonous, glabrous. Seeds: embryo curved. x = 20.

Distribution

w United States.

Discussion

Species 2 (2 in the flora).

Stenogonum is clearly allied to Eriogonum subg. Ganysma, specifically E. trichopes and its close relatives. The genus is readily distinguished from Eriogonum by an involucre reduced to a series of two foliaceous whorls of three lanceolate bracts.

Key

1 Leaves basal; peduncles flexed; stems mostly erect, sparsely glandular Stenogonum flexum
1 Leaves basal and cauline; peduncles straight; stems mostly spreading, glabrous Stenogonum salsuginosum
Facts about "Stenogonum"
AuthorJames L. Reveal +
AuthorityNuttall +
Common nameTwo-whorl buckwheat +
Distributionw United States. +
EtymologyGreek stenos, narrow, and gonos, seed, alluding to achene +
Publication titleProc. Acad. Nat. Sci. Philadelphia +
Publication year1848 +
Referencereveal1977a +
Source xmlhttps://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse grained fna xml/V5/V5 899.xml +
SynonymsEriogonum sect. Stenogonum +
Taxon familyPolygonaceae +
Taxon nameStenogonum +
Taxon parentPolygonaceae subfam. Eriogonoideae +
Taxon rankgenus +
VolumeVolume 5 +