Wayne P. Armstrong, 21 July 2005

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According to quantitative data and images compiled by Wayne P. Armstrong and Tom Chester, Brodiaea populations from San Marcos, Kearny Mesa, Mission Trails and Otay Mesa in San Diego County are Coastal BTK rather than B. jolonensis. We are referring to these populations as Coastal BTK because they may be different from Niehaus' B. terrestris ssp. kernensis from Kern and Tulare Counties. In "A Biosystematic Study of the Genus Brodiaea," Univ. of Calif. Publications in Botany Vol. 60 (1971), T.F. Niehaus cites a collection of B. jolonensis (# 662) from Otay Mesa. As of June 2005, we have been unable to locate any brodiaeas at this site, probably because of the extirpation of Niehaus' original collection site. Unfortunately, herbarium specimens do not show some of the detailed floral characteristics that distinguish B. jolonensis from Coastal BTK. According to Niehaus (1971), the vascular strand pattern of inner perianth segments may be used to distinguish between B. jolonensis and B. terrestris ssp. kernensis. In July, 2005 Tom Chester and I examined the vascular strand pattern of inner perianth segments of #662. Our results are published on-line in this report.

Table 4 on page 12 of Niehaus' monograph compares the vascular pattern of perianth segments from all species of Brodiaea in California. The outer and inner perianth segments contain three primary vascular bundles, visible under 10x magnification. Each of these bundles contains one-several strands of vessels with spirally thickened secondary walls. The pattern of these strands is different depending on the species. In B. terrestris ssp. kernensis each inner perianth segment contains three strands per vascular bundle, a pattern described as 3-3-3 by Niehaus (1971). Coastal BTK also has three strands per vascular bundle, a total of nine strands. In B. jolonensis each inner perianth segment contains one strand per vascular bundle, a pattern described as 1-1-1 by Niehaus. I have also observed B. jolonensis with four vascular strands. The strands are not always well-defined all along the vein, and appear to merge in places. This may explain why the number of strands is three or four; however, B. jolonensis has a very different vascular strand pattern compared with Coastal BTK in southern California.

In order to view the strand pattern, an inner perianth segment is soaked in 10 percent NaOH. This clears away tissue surrounding the vein so that the vascular strands are more prominent. The segment is placed on a microscope slide with a cover slip. A drop of stain, such as safranin, may be added to intensify the vascular strands. The entire strand pattern can be viewed with a compound microscope at 100x magnification. The strands of individual bundles can be viewed at 400x, although it is difficult to clearly show all of the strands due to the limited depth of field at this magnification.

The following four images show the vascular strand pattern of an inner perianth segment from #622. Each vascular bundle is composed of multiple strands, unlike the single strands of B. jolonensis. Because of limited depth of field and orientation (overlapping) of the vascular strands, it is often difficult to capture well-defined triplet strands of all three bundles in a single image. The following images collectively indicate that the vascular bundles contain multiple (triplet) strands. Therefore, we must conclude that #622 is not B. jolonensis. B. jolonensis from Monterey County has a total of only three or four vascular strands compared with up to nine for Coastal BTK. #662 appears to be the same species as other populations of Coastal BTK in coastal San Diego County with a tentative sporophyte chromosome number of 36. This may also be the same species that occurs on Catalina Island. More chromosome studies and observations are needed to determine whether Coastal BTK is different from populations of B. terrestris ssp. kernensis in Kern County and populations of Montane BTK in the mountains of southern California.

Niehaus #662 does not have the characteristic vascular pattern of the inner perianth segments described by Niehaus (1971) for B. jolonensis. As of June 2006, Tom Chester and I have not found any populations of B. jolonensis in southern California, from Santa Barbara and Los Angeles Counties to Otay Mesa in San Diego County. #662 appears to be the same species as other populations of Coastal BTK throughout coastal southern California. Coastal BTK has the vascular pattern described by Niehaus for B. terrestris ssp. kernensis. According to Niehaus, its sporophyte chromosome number is 36 (6n), compared with 48 (8n) for species in Kern and Tulare Counties.

Niehaus reported a hexaploid sporophyte number of 36 for #662 on Otay Mesa. It seems likely that the chromosome number of 36 is typical of other populations of Coastal BTK in southern California that have been confused with B. jolonensis for decades. Niehaus also determined a chromosome number of 36 for a sample of "B. jolonensis" from Santa Barbara County, different from the number 12 determined from plants in Monterey County. In addition, the vascular pattern of "B. jolonensis" in Santa Barbara (Gaviota Pass) and from Santa Catalina and San Miguel Islands appears to be the same as Coastal BTK in southern California. Brodiaea jolonensis appears to be endemic to the Coast Ranges of central California, primarily in Monterey County, and does not occur in southern California.

Chromosome numbers need further study. Niehaus' numbers of 36 for "B. jolonensis" in San Diego and Santa Barbara Counties obviously refer to Coastal BTK. My count for Coastal BTK in San Marcos is at least 36. Preliminary studies by Dale McNeal at University of the Pacific indicate that the number for Coastal BTK on Otay Mesa may be greater than 40. An exact count is difficult because small chromosomes are often obscured by the larger ones.

Southern California populations of Coastal BTK and Montane BTK do not key out adequately in the Jepson Manual (1996), which is based on Niehaus' 1971 monograph. Couplets 18 and 18' (page 1182) separate B. jolonensis from B. terrestris:

The terms "purple ovary" and "green ovary" are only reliable in fresh flowers because all ovaries in pressed herbarium specimens typically turn purple or purplish-brown. They are useful in separating these species in the field. The characteristic shape of soft anther connective tissue is difficult to preserve is dried herbarium specimens.

The apex of the anther axis (anther connective) of B. terrestris ssp. terrestris of central California clearly terminates in a toothed appendage. Populations of ssp. kernensis in Kern County also have this dentate anther axis. The dentate appendage is formed from a proliferation of the connective tissue. Coastal BTK and Montane BTK in southern California generally do not have this prominent dentate anther axis. Instead they have an entire, V-shaped or U-shaped notch that is also characteristic of B. jolonensis. In some populations of Coastal BTK there may be a minute lobe at the base of this notch. The term "dentate anther axis" is not useful or reliable in keying out Coastal BTK or Montane BTK in southern California.

At this time we are confident that Niehaus #662 is Coastal BTK and not B. jolonensis. Populations of Coastal and Montane BTK in southern California have similar characteristics, but also contain considerble variability with respect to the shape of staminodes. Montane BTK from the Laguna Mountains typically have inrolled staminodes; however, when grown in Escondido from a corm (June 2006), the staminodes were conspicuously hooded like Coastal BTK. In general, Montane BTK is similar to populations of BTK observed in Kern County. Additional research is necessary to determine whether they represent one large and variable subspecies.

Wayne P. Armstrong and Tom Chester, 3 June 2006

Comparison of BTK and B. jolonensis Vascular Patterns More Vascular Strand Patterns Of BTK & B. jolonensis