Plants of Southern California: Comments On Milt McAuley's Wildflowers of the Santa Monica Mountains

Please read the introduction to this page first!

This is a superb reference for the Santa Monica Mountains, and is so comprehensive and reasonably-priced that it has been used for many other areas of Southern California outside of the Santa Monica Mountains. The 1996 second edition contains 496 color photographs, and nearly as many line-drawings, of almost 500 taxa, with a basic description of almost 1,000 taxa including flowering times.

I have not read the book thoroughly, so my personal comments are not very extensive, giving five misidentifications I have come across in the course of other work and a quick scan of the photographs. The comments here include ones given to me by others, and are attributed to the person submitting the comment.

• "Squaw spurge", plate 97, pp. 59, 333, "Chamaesyce melanadenia". The plant shown in the photograph looks prostrate, glabrous and green, very unlike the mounded, woolly and reddish-purplish taxon C. melanadenia. Compare the plants shown in the photograph and in the illustration with this picture of C. melanadenia showing its typical hairy leaves and tomentose ovary.

  I can't be sure of the taxon in the photograph in McAuley without seeing more details, especially the leaf stipules. However, it is far more likely that the id is C. polycarpa, which is the most common Chamaesyce in cismontane Southern California, and the most frequent species in the Santa Monica Mountains according to the Flora of the Santa Monica Mountains (1986). (By the way, C. polycarpa is also frequently misidentified as C. albomarginata.)

• "Wand chicory", plate 115, pp. 63, 252, "Stephanomeria virgata". The plant shown is S. diegensis. This is probably the single most common mistake in all floras, wildflower brochures, and wildflower books in Southern California. However, calling this a mistake is too strong a word; instead, this misidentification simply reflects how slowly new botanical information travels throughout the community and takes root.

  This error stems from confusion prior to 1971, when S. diegensis was separated from S. virgata by Gottlieb. Munz in his 1974 Flora of Southern California did not incorporate S. diegensis, so it was not until 1993, when the Jepson Manual came out, that most botanists were even cognizant of the distinction.

  The species are clearly separate, distinguished most obviously by the number of ligules. S. diegensis has 5-15 ligules per head, whereas S. virgata has 5-9. A more robust technical distinction is that the achenes of S. diegensis are grooved, and those of S. virgata are not. Also, the pappus bristles of S. diegensis are plumose only 75-90% to their base, whereas the pappus bristles of S. virgata are plumose all the way to their base.

  As far as I know, all coastal plants in Southern California are S. diegensis; S. virgata is an inland taxon. Plants I keyed out from the Saddle Peak Trail in the Santa Monica Mountains are S. diegensis. Barry Prigge, an author of the current Flora of the Santa Monica Mountains, reports that everything I have seen from Santa Monica Mountains with fruit is S. diegensis.

  The plants in the photo and drawings in McAuley have ~15 ligules per head or even more, making them very clear S. diegensis.

  See S. diegensis for more information.

• "Moth mullein", plate 144, pp. 71, 523, "Verbascum blattaria". Jay Sullivan discovered that the pictured taxon is actually V. virgatum. The picture clearly shows 1-3 sessile flowers per node, fitting V. virgatum, inconsistent with the 1 flower per node with 10-15 (25) mm pedicels of V. blattaria. The drawing in McAuley on p. 523 is indeed V. blattaria, and looks very different from the plant in the picture in plate 144.

  Now, what is really interesting is that no Verbascum appears in the 1986 Raven et al Flora of the Santa Monica Mountains! Only V. thapsus is reported (not vouchered) to be in the Santa Monica Mountains in Gibson and Prigge! (V. virgatum is listed in Gibson and Prigge, but with zero vouchers and zero reports.)

  So if any reader finds any specimens of V. blattaria or V. virgatum in the Santa Monica Mountains or Simi Hills, they should voucher it, after securing permission to do so. McAuley gives the location as being Santa Maria Creek, which is probably a good place to start looking for it.

• "Mediterranean mustard", plate 160, pp. 75, 274, "Hirschfeldia incana". I can't be 100% sure without seeing more of the plant, but the plant in the photograph, with its broad cauline ~glabrous leaves, looks much more like Brassica nigra, black mustard, than H. incana. B. nigra is also far more common in the Santa Monica Mountains.

  See Mustard (Brassica nigra and Hirschfeldia incana): How To Tell The Difference for more information on how to tell the two apart.

• "Silverweed", plate 183, pp. 81, 495, "Potentilla anserina ssp. pacifica". An anonymous reader with a very sharp eye points out that the photograph is of puncture-vine, Tribulus terrestris. These species look extremely similar at a glance, but the plant in the photograph has the entire leaflets, with a white midvein, of Tribulus terrestris (see this photograph), and not the clearly-toothed leaflets, without a white midvein, of Potentilla anserina (see this photograph).

• "Annual Malocothrix", plate 211, pp. 88, 239, "Malacothrix clevelandii". The plant shown is smooth cat's ear, Hypochaeris glabra, which is mentioned in the text but with no photograph linked to it.

  This particular picture confused me for years. Every plant that looked like the one in the picture always keyed out to Hypochaeris glabra. It was only when I finally found a true Malacothrix clevelandii that I found it was a much different-looking species. M. clevelandii is a much less robust, more spindly plant. See Keir Morse's pix and the Jepson Manual illustrations on pp. 297 and 317.

  The Jepson Manual key to separate these two species is whether the receptacle (the structure to which the flower parts are attached) has chaff scales (H. glabra) or is naked or with only fragile bristles (M. clevelandii). A possibly-easier way to separate them is to look at the phyllaries: H. glabra has phyllaries of various lengths, in ~4 series, whereas M. clevelandii has phyllaries in mainly just two lengths, with the outermost phyllaries less than half the length of the innermost ones (just barely visible in Morse's pix and here).

  Once you've seen both species, you'll never confuse them.

• "Wild Brodiaea", plate 369, pp. 128, 410, "Brodiaea jolonensis". This is also not really a mistake, since nearly every botanist has followed the determinations of the expert on Brodiaeas, T. Niehaus, and the erroneous key in Munz 1974.

  Niehaus put his stamp of approval on specimens from coastal Southern California as being "B. jolonensis" in 1971, even though it turns out his own vouchers from Southern California are not that taxon using Niehaus' own characteristics. The whole history of Brodiaea classification shows that this is a genus where it is extremely important to have fresh samples and field observations of the various species.

  It was only in 2005 that Wayne Armstrong and I determined definitively that B. jolonensis does not exist in Southern California; all specimens so determined are misidentified B. terrestris ssp. kernensis.

• "Beach Saltbush", plate 408, pp. 138, 303, "Atriplex leucophylla". Michael Charters and an anonymous reader both said the pictured species is actually California croton, Croton californicus. The species look quite similar in many respects, with two main differences. First, the leaf of A. leucophylla is densely white-scaly, whereas the pictured leaf is just hairy, fitting C. californicus. Second, the inflorescence of A. leucophylla is axillary, whereas the pictured inflorescence is terminal, fitting C. californicus. Compare the following pictures of the leaves, A. leucophylla vs. C. californicus, and the inflorescences, A. leucophylla vs. C. californicus.

• "Garden Pea", p. 358, "Pisum sativum". The plant shown is perennial sweet pea, Lathyrus latifolius. This error was discovered thanks to a photograph taken by Michael Charters, whose identification came from Michael's match to the illustration in McAuley.

  The difference is mostly easily seen in the leaf stipules. The plant in McAuley's illustration has small stipules, which is typical of Lathyrus, whereas Pisum has very large stipules that resemble leaflets. Compare the small stipules in the Jepson Manual illustration for L. latifolius on p. 615 to the huge stipules that wrap around the stem for P. sativum on p. 645, or in these online pix: P. sativum vs. L. latifolius.

• Scrub Oak, plates 455, 469, pp. 149, 153, 367, "Quercus dumosa". Jay Sullivan points out that the current name for this taxon is Q. berberidifolia. Q. berberidifolia used to be included with the rare taxon now known as Q. dumosa until about 1982, when it was recognized that these two species were actually quite distinct if one only looked at the hairs on the underneath of the leaf. See History Of The Scrub Oak Species. Q. dumosa is only found on the coast near Santa Barbara, the Dana Point Highlands in Orange County, and in southern San Diego County and northern Baja California.

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Copyright © 2006 by Tom Chester
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Last update: 2 March 2006