Directory       News       Site Map       Home
         
    Jepson eFlora: Taxon page
Key to families | Table of families and genera

Previous taxon Indexes to all 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 |
Previous taxon

APOCYNACEAE DOGBANE FAMILY

Thomas J. Rosatti, except as noted

Annual, perennial herb, shrub, tree, often vine; sap generally milky. Leaf: simple, alternate, opposite, subwhorled to whorled, entire; stipules 0 or small, finger-like. Inflorescence: axillary or terminal, cyme, generally umbel- or raceme-like, or flowers 1–2. Flower: bisexual, radial; perianth parts, especially petals, overlapped, twisted to right or left, at least in bud; sepals generally 5, fused at base, often reflexed, persistent; petals generally 5, fused in basal ± 1/2; stamens generally 5, attached to corolla tube or throat, alternate lobes, free or fused to form filament column and anther head, filament column then generally with 5 free or fused, ± elaborate appendages abaxially, pollen ± free or removed in pairs of pollinia; nectaries 0 or near ovaries, then 2 or 5[10], or in stigmatic chambers; ovaries 2, superior or ± so, free [fused]; style tips, stigmas generally fused into massive pistil head. Fruit: 1–2 follicles, (capsule), [berry, drupe]. Seed: many, often with tuft of hairs at 1 or both ends.
200–450 genera, 3000–5000 species: all continents, especially tropics, subtropical South America, southern Africa; many ornamental (including Asclepias, Hoya, Nerium, Plumeria, Stapelia); cardiac glycosides, produced by some members formerly treated in Asclepiadaceae, used as arrow poisons, in medicine to control heart function, and by various insects for defense. [Fishbein 2001 Ann Missouri Bot Gard 88:603–623] Asclepiadaceae ("asclepiads"), although monophyletic, included in Apocynaceae because otherwise the latter is paraphyletic. Complexity of floral structure, variation in asclepiads arguably greatest among all angiosperms. Pattern of carpel fusion (carpels free in ovule-bearing region, fused above), present ± throughout Apocynaceae (in broad sense), nearly unknown in other angiosperms. Base chromosome number generally 11; abundance of latex, generally small size of chromosomes evidently have impeded cytological investigations. —Scientific Editor: Bruce G. Baldwin.
Unabridged references: [Civeyrel et al. 1998 Molec Phylogen Evol 9:517–527; Rosatti 1989 J Arnold Arbor 70:307–401]

Key to Apocynaceae

ASCLEPIAS MILKWEED

Thomas J. Rosatti & Carol A. Hoffman

Annual, perennial herb, shrub. Stem: prostrate to erect. Leaf: generally opposite (alternate, whorled), each pair at right angles to those below, above, generally persistent; blade narrow-linear to ovate or cordate. Inflorescence: terminal or at generally upper nodes, umbel-like cyme. Flower: ring of tissue at base of corolla 0; filament column appendages (hoods) free, elevated above corolla base or not, each often with an elongate projection (horn) attached to inside, margins converging and meeting or nearly meeting adaxially but not fused; anthers fused into anther head around and fused to pistil head, pollen in pollinia; pistil head flat or conic on top; nectaries in stigmatic chambers. Fruit: erect (but generally on pendent pedicel) or pendent, lance-ovoid to ovoid, smooth or with tubercles.
In narrow sense of genus, 100 species: North America, Central America, perhaps South America. (Greek physician Aesculapius) Fresh flowers generally better for determining relative positions of parts; hoods may have near anther head 2 ± sickle shaped lobes each that may ± resemble horns. A. linaria not outside cultivation in California, so deleted here; previous inclusion in TJM2 (2012) based on faulty locality data.
Unabridged references: [Liede-Schumann & Meve 2006 http://www.uni-bayreuth.de/departments/planta2/research/databases/delta_as/www/asclep.htm; Woodson 1954 Ann Missouri Bot Gard 41:1–211]

Key to Asclepias

A. latifolia (Torr.) Raf. BROADLEAF MILKWEED
NATIVE
Perennial herb, very hairy, less so in age. Stem: erect. Leaf: opposite; petiole short to 0; blade generally wide-elliptic (lanceolate, ovate), base tapered, obtuse, or cordate, tip obtuse to truncate or notched, generally mucronate. Inflorescence: peduncle [0–]1.5–2.7 cm. Flower: corolla reflexed to spreading, cream-green, purple-tinged abaxially or not; hoods ± elevated above corolla base, exceeded by to at ± same level as anther head, cream, purple-tinged or not; horns exserted, at ± same level as hoods, converging over anther head or not. Fruit: erect on ± reflexed pedicels. Seed: 7–8 mm.
2n=22. Dry washes; ± 150 m. Inner North Coast Ranges (Rumsey, Yolo Co., 1912, extirpated); to South Dakota, Texas, Mexico. May–Jun [Online Interchange]
Unabridged note: Based on key in Woodson: UC449991 (Tracy I. Storer; Jun 29, 1912; Rumsey, Yolo Co.), identified on label doubtfully as Asclepias latifolia (Torr.) Raf., may belong instead to Asclepias eriocarpa Benth. (peduncles in Asclepias latifolia 0–1.5 cm, in Asclepias eriocarpa 1–10 cm; on specimen ± 2.5 cm, and flowers few and past their prime); the material in a photocopy of MO1170403 (R.W. Schery & E. Curtis; July 19, 1939, 30 miles west of Grant Park, county not indicated, but the only Grant Park in the Jepson Place Name Index is in southwestern Ventura Co., well within the range of Asclepias eriocarpa and Asclepias erosa, but quite far away from the one dot indicated in California for Asclepias latifolia by Woodson, which evidently is in Inyo Co., possibly representing a locality within 30 miles – but to the east – of the Grant Grove area of Kings Canyon National Park, known in 1939 as General Grant National Park or simply Grant Park), identified on label (handwritten on otherwise typed label) and on annotation by S.P. Lynch in 1984 as Asclepias latifolia, also may belong instead to Asclepias eriocarpa. Tim Lowrey (pers. comm.), who is familiar with the sp. in New Mexico, remembers as a child plants possibly belonging to Asclepias latifolia occurring on dry washes near his family home near Rumsey (collection locality for UC449991). Final resolution will not occur at least until after a visit to the Rumsey area, planned for Spring of 2009, but until then it seems most judicious to treat this taxon as extirpated in California.

Previous taxon: Asclepias fruticosa
Next taxon: Asclepias nyctaginifolia

Contact/Feedback

Name search

Citation for the whole project: Jepson Flora Project (eds.) 2013. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on Aug 23 2014
Citation for this treatment: [Author of taxon treatment] 2013. Asclepias, Revision 1, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=14392, accessed on Aug 23 2014

Copyright © 2014 Regents of the University of California
We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.


Geographic subdivisions indicated for the distribution of Asclepias latifolia Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
READ ABOUT YELLOW FLAGS
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).

View elevation by latitude chart
Data provided by the participants of the Consortium of California Herbaria.
View all CCH records

 

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.