Calycadenia multiglandulosa DC.

Last Addition: July 3, 2000.

Each "thumbnail" image below is linked to a larger photograph.

As presently treated, C. multiglandulosa includes subsp. bicolor from the Sierra foothills, subsp. cephalotes primarily from San Francisco Bay north in the Coast Range, and subsp. robusta primarily from San Francisco Bay south in the Coast Range.  It also includes the species previously known as C. hispida (including subsp. reducta).  Populations occur at elevations ranging from about 75 - 1000 m.  Flower color ranges from white to cream or to bright yellow (in some of the populations previously treated as C. hispida.)  As the species epithet suggests, C. multiglandulosa exhibits a profusion of tack-shaped glands, both on the peduncular bracts and usually also on the phyllaries and chaff scales surrounding the heads.  The chromosome number is n = 6, and despite considerable morphological variation over the range of the species, several artificial hybrids among geographically widely separated populations yielded no evidence of the sort of chromosomal reorganization that is so evident in C. pauciflora and C. ciliosa.   However, two forms of nucleolar-organizing, supernumerary chromosomes and a type of "micro" supernumerary chromosome are are found mutually exclusively in certain coast range populations.  Putative natural hybridization of C. multiglandulosa with C. mollis and C. truncata have been observed at one site of sympatry for each interspecific combination.  Natural hybridization between the entities formerly treated as C. multiglandulosa subsp. bicolor and C. hispida subsp. hispida has also been observed.  Artificial interspecific hybrids between C. multiglandulosa (as presently treated) and C. fremontii, C. oppositifolia, C. pauciflora (n = 5 and n = 6 races), and C. spicata have been produced experimentally.

cal_mub_habitats.jpg (12514 bytes) cal_mub_mids.jpg (9085 bytes)
Habitat and closer view of the taxon formerly treated as subsp. bicolor from El Dorado County.
cal_mub_gls.jpg (9457 bytes) View of head of subsp. bicolor showing profusion of tack-shaped glands on peduncular bracts, phyllaries, and peripheral receptacular scales.
cal_mub_fls.jpg (9451 bytes) Florets from the head of a population of subsp. bicolor from Amador County.
cal_muc_habs.jpg (16458 bytes) cal_muc_fls.jpg (11845 bytes)
1 - A population of the species formerly treated as subsp. cephalotes from Napa County. 2 - Terminal cluster of flowering heads of subsp. cephalotes from Sonoma County.  Such terminal clustering of heads is one of the features characteristic of this subspecies. 3 - Face view of single head.
cal_mur_habitats.jpg (8666 bytes) cal_mur_habs.jpg (13408 bytes) cal_mur_fls.jpg (10844 bytes)
Habitat, habit, and close-up of head representing population of subsp. robusta from Santa Clara County.
cal_his_alb_habs.jpg (11923 bytes) cal_his_alb_heads.jpg (13973 bytes)
White-flowered form of the taxon previously recognized as C. hispida subsp. hispida forma alba from Monterey County.
cal_his_habs.jpg (5060 bytes) cal_his_heads.jpg (15880 bytes) cal_his_gls.jpg (10901 bytes) cal_his_fls.jpg (8806 bytes)
Yellow-flowered forms of the taxon formerly recognized as C. hispida subsp. hispida.   1 - habit of greenhouse grown progeny.  2 - Flowering head, note narrow central lobe of ray corolla characteristic of C. multiglandulosa in general.   3 - Flower head in bud showing long, narrow peduncular bracts typical of the populations formerly treated as C. hispida.  4 - Close view of florets.  1,4 from Calaveras County, 2,3 from El Dorado County.

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