Calyptridium parryi (Montiaceae, formerly Portulacaceae) putatively comprises four varieties: arizonicum, hesseae, nevadense, and parryi. We performed a detailed phenetic analysis of seed, fruit, and sepal morphology in order to assess the distinction and rank of these varieties. We treated the San Pedro Martir Mountains, Baja California populations of C. parryi as a separate taxonomic unit in these studies, given their great disjunct distribution. In addition, we included the very similar and largely sympatric C. monandrum in these analyses. Results from ANOVA and principal components analysis indicate that the six entities examined are, to various degrees, morphologically diagnosable. Calyptridium parryi varieties hesseae, nevadense, and parryi show some overlap in features, and we propose keeping these as varieties. Populations from the San Pedro Martir Mountains are distinct from other varieties of C. parryi, possibly warranting varietal status, but further studies with more samples are needed to confirm this. However, we conclude that C. parryi variety arizonicum is different enough in several features and geographic range to warrant species status, by a taxonomic/morphologic species concept. Calyptridium monandrum should be retained as a separate species.

Previous field studies of the reproductive biology of the San Fernando Valley spineflower, Chorizanthe parryi var. fernandina (S. Watson) Jeps. suggested that pollination by ants might be an important feature of this endangered polygonous taxon. This conclusion was based on observations that native ants were abundant floral visitors and constant to this species. We conducted the current study to explore more closely the possibility that native ants were facilitating pollination and resulting in viable seed set. Based on our data, ants can indeed be effective pollinators of spineflower. Fruit set was 57% higher in flowers exposed to ant visitation, compared to 27% in control flowers where ants were excluded. Further, a 25.7% germination rate was observed for achenes produced in the absence of ants, in contrast to a 61% rate in those produced in the presence of ants. We suggest that ant pollination may be more prevalent in drier climates, ant production of inhibitory substances may not be a severe limitation to their function as pollinators, invasive Argentine ants may pose a threat to plants pollinated by ants, and self-pollination may not be a negative attribute for ant pollinated plants.

Savannas are open communities with a woodland and grassland phase. Some species are restricted to one phase or the other with some in both. The central Texas Edwards Plateau is mainly a savanna community with an east to west rainfall gradient and a tree density gradient with both factors being reduced in the west. We examined gas exchange rates of sun and shade leaves of three perennial species of Asteraceae, Simsia calva (bush sunflower), Wedelia texana (hairy wedelia,) and Brickellia cylindracea (brickell-bush). Maximum photosynthetic rates (A_max), light saturation points (L_sat), ambient light levels, leaf mass per area, leaf conductance, and transpiration rates (E) for sun leaves were significantly greater than shade leaves for all three species. Mean A_max rates were 32.8, 23.2 and 21.2 µmolCO₂/m²/s for sun leaves of S. calva, W. texana and B. cylindracea respectively. For shade leaves, rates were 21.3, 15.2 and 12.9 µmolCO₂/m²/s respectively for the same species. Mean R_d (dark respiration) rates were 3.00 µmolCO₂/m²/s for sun leaves and 1.1 µmolCO₂/m²/s for shade leaves of S. calva. R_d rates for sun and shade leaves of W. texana and B. cylindracea were mostly lower but only significantly different for B. cylindracea. There were no significant differences between sun and shade leaves for the initial slope or quantum yield for any of the species. Leaf mass per area was greater for sun leaves of all species. A_max rates for sun leaves were high as expected for sun plants, but A_max rates for shade leaves were fairly high as well, probably because of the relatively open nature of the sub-shrub canopy. Most factors measured were high and suggest that these plants are sun plants or facultative species. These measurements would help explain why these species are present in the full sun, open grassland phase of these central Texas savanna communities and not below the woodland canopy where their growth and survival would be reduced because of lower light levels.

The mitotic chromosome count for Toxicoscordion exaltatum (2n  =  22), documented for the first time here, matches the number formerly reported for other species in the genus. A base number of x  =  11 is synapomorphic for Toxicoscordion. An updated overview of this recently resurrected segregate genus is given.

The name Zeltnera muhlenbergii (Griseb.) G. Mansion is here applied to a species native from Monterey County, California, to southwestern British Columbia. From Z. davyi (Jeps.) G. Mansion, a California endemic to which the name Z. muhlenbergii has sometimes been misapplied, Z. muhlenbergii differs in that its calyx lobes are not keeled or have keels proximally only, to 0.25 mm wide, and its corolla lobes are 1–2 mm wide; in Z. davyi the keels of the calyx lobes are 0.3–0.6 mm wide and the corolla lobes are 2–3 mm wide. Zeltnera muhlenbergii has often been confused with Centaurium tenuiflorum (Hoffmanns. & Link) Fritsch ex Janch. s.l., a species naturalized from Eurasia, now established in Pacific and Gulf coastal North America. From C. tenuiflorum, Z. muhlenbergii differs most notably in its flabelliform rather than ovate stigmatic lobes and in its more open, non-corymboid cymes.

Lomatium tamanitchii (Apiaceae), is a newly discovered substrate-specific, narrow endemic species. The species grows on clay soils in grassland swales and gentle slopes in the Columbia Hills of eastern Klickitat County in south-central Washington State. A small disjunct occurrence has also been recently recognized in Union County, Oregon. The species is most typically distinguished by a multi-branched caudex surmounting a large, thick, blunt-tipped taproot. It is identified by its sparsely to densely short hairy leaves with broadly winged petioles, and its narrowly elliptical dorso-ventrally compressed fruits that have short hairs and distinct narrow raised ventral ribs. Lomatium tamanitchii is clearly distinct from all other species in the genus as based primarily upon gaps in characters of fruit morphology and vestiture. Populations occur in dense near-monocultures strictly confined to shrink-swell soils derived from devitrified silicic volcanic ash on massive landslide deposits. The known range of L. tamanitchii is restricted to a small area in eastern Klickitat Co., Washington and several hundred plants in a newly-discovered disjunt population approximately 180km distant in Union Co., Oregon. This limited distribution raises conservation concerns. Lomatium tamanitchii is compared with morphologically similar taxa growing in nearby areas of the Columbia Basin.