Jepson eFlora: Taxon page
Vascular Plants of California
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon

Anulocaulis annulatus

Higher Taxonomy
Family: NyctaginaceaeView DescriptionDichotomous Key
Habit: Annual, perennial herb, subshrub, [shrub, tree], glabrous or hairy. Stem: often forked. Leaf: opposite, sessile or petioled, pairs generally unequal; blade generally entire. Inflorescence: generally forked; spike, head-like cluster, or umbel, flowers rarely 1, bracts forming a calyx-like involucre or not. Flower: bisexual, generally +- radial (bilateral), sometimes cleistogamous in some genera; perianth of 1 whorl, generally petal-like, bell- to trumpet-shaped, base hardened, tightly surrounding ovary in fruit, lobes 3--5, generally notched to +- lobed; stamens 1--many; ovary superior (appearing inferior due to hardened perianth base), style 1. Fruit: achene in hardened perianth base; round to +- flat; smooth, angled, ribbed, or winged; glabrous, hairy, or glandular.
Genera In Family: 30 genera, 350 species: warm regions, especially America; some ornamental (Bougainvillea; Mirabilis, four o'clock).
eFlora Treatment Author: Andy Murdock, except as noted
Scientific Editor: Thomas J. Rosatti.
Genus: AnulocaulisView Description 

Common Name: RINGSTEM
Habit: Perennial herb from thick caudex. Stem: little-branched, erect, > 7 mm diam; internodes with sticky brown ring. Leaf: few, +- in lower 1/2, petioled; blade oblong to round, thick. Inflorescence: openly branched; flowers in head, raceme, or umbel-like cluster; bracts 1--3, free, not forming involucre. Flower: perianth funnel-shaped; stamens 3, exserted; stigma +- spheric, exserted. Fruit: inconspicuously 10-ribbed, glabrous.
Species In Genus: 5 species: especially Chihuahuan Desert, northeastern Mexico. Etymology: (Latin: ring stem, from sticky ring on internode) Note: Closely related to Boerhavia.
eFlora Treatment Author: Andy Murdock & Richard Spellenberg
Reference: Spellenberg 2003 FNANM 4:28--30
Anulocaulis annulatus (Coville) Standl.
Stem: < 1.5 m. Leaf: blade 3--10 cm, oblong to round-reniform, hairs stiff, with enlarged, dark, glandular base. Inflorescence: terminal, panicle-like, 1--2 branches per node, each ending in head-like cluster of flowers; bracts leaf-like, reduced; peduncle 15--40 mm. Flower: perianth +- 8 mm, tube +- green, hairy, limb pale pink. Fruit: 4--5 mm, spindle-shaped, gray-brown. Chromosomes: 2n=48.
Ecology: Rocky slopes, canyons; Elevation: < 1200 m. Bioregional Distribution: ne DMoj (Death Valley region). Flowering Time: Apr--May
Synonyms: Boerhavia annulatus Coville
Jepson eFlora Author: Andy Murdock & Richard Spellenberg
Reference: Spellenberg 2003 FNANM 4:28--30
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

Previous taxon: Anulocaulis
Next taxon: Boerhavia

Name Search

Botanical illustration including Anulocaulis annulatus

botanical illustration including Anulocaulis annulatus


Citation for this treatment: Andy Murdock & Richard Spellenberg 2012, Anulocaulis annulatus, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on August 12, 2022.

Citation for the whole project: Jepson Flora Project (eds.) 2022, Jepson eFlora,, accessed on August 12, 2022.

Anulocaulis annulatus
click for enlargement
© 2016 Steve Matson
Anulocaulis annulatus
click for enlargement
© 2007 Aaron Schusteff
Anulocaulis annulatus
click for enlargement
© 2010 Barry Breckling
Anulocaulis annulatus
click for enlargement
© 2010 James M. Andre
Anulocaulis annulatus
click for enlargement
© 2016 Steve Matson
Anulocaulis annulatus
click for enlargement
© 2010 Barry Breckling

More photos of Anulocaulis annulatus in CalPhotos

Geographic subdivisions for Anulocaulis annulatus:
ne DMoj (Death Valley region).
1. You can change the display of the base map layer control box in the upper right-hand corner.
2. County and Jepson Region polygons can be turned off and on using the check boxes.
map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).


Data provided by the participants of the  Consortium of California Herbaria.
View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).