Tiburon mariposa lily opens in summer light
June 6, 2026
The summer air carries the scent of dry grass and salt from the bay. Here on the slopes above Tiburon, the longest days of the year have arrived, and with them, something rare unfolds in the coastal scrub. Step outside if you can, or find a window that opens to summer light. The heat builds slowly in the morning, and by noon, the hillsides shimmer.In this narrow band of serpentine soil, the Tiburon mariposa lily opens its three-petaled flowers to the June sun. Each bloom spans three inches across, white petals marked with purple chevrons at the base, surrounding a cluster of yellow anthers. The lily grows from a bulb buried six inches deep in the rocky soil, sending up a single stem that can reach two feet tall. This threatened wildflower exists nowhere else on earth except these serpentine slopes in Marin County. The plant spends eleven months of the year as an underground bulb, emerging only when the soil warms and the rains have stopped.The mariposa lily shares this harsh ground with other rarities. Long-rayed brodiaea, also threatened, clusters its purple flowers on nearby slopes. Marin dwarf-flax, another endemic, opens tiny white flowers among the rocks. These native plants have adapted to serpentine soil, which contains high levels of magnesium and heavy metals that most plants cannot tolerate. The invasive pale flax and common cat's-ear struggle here, giving the natives an advantage in their own territory. The rocky, nutrient-poor soil that challenges most plants becomes a refuge for species that evolved with it. Each lily plant may live for decades, blooming only when conditions align perfectly. The bulbs can remain dormant through drought years, waiting for the right combination of winter rain and summer heat.Bees and butterflies find the mariposa lilies during their brief flowering window. The flowers produce nectar deep in their cups, accessible to long-tongued pollinators. Each successful pollination produces a three-chambered seed capsule that splits open in late summer, releasing seeds that may take seven years to produce their first flower. Most seeds never germinate. Those that do must navigate the narrow window between too much moisture and too little, between the spring rains and the summer drought. The population here numbers in the hundreds, each plant a survivor of this precise timing.Close your eyes and feel the summer heat building on your skin. Somewhere on these slopes, white petals catch the light, opening wider as the temperature climbs. The air shimmers above the serpentine, and the scent of warming earth rises from the ground.
Anna's hummingbirds and ruby chalice clarkia
May 22, 2026
The hillsides around Tiburon hold their color differently in late spring. Where winter rains once darkened the soil, patches of ruby chalice clarkia now bloom in clusters of deep pink, their four-petaled flowers catching the morning light. The Douglas-fir trees show fresh green needle tips, and the poison oak leaves have settled into their glossy three-leaflet patterns. This is the season when the landscape and its smallest aerial residents move in careful synchrony.Anna's Hummingbirds are deep into their nesting season now, the males' territorial calls sharp and frequent from the coyotebrush and willow branches. A female hovers at the clarkia blooms, her needle-thin bill probing each flower for nectar. She moves methodically from bloom to bloom, her wings beating so rapidly they blur into transparency. The timing is precise. The clarkia flowers produce their richest nectar in the morning hours, and the hummingbirds have learned this schedule. As she feeds, pollen grains stick to the feathers around her bill and throat, pale yellow dust that she will carry to the next patch of flowers.The relationship runs deeper than simple feeding. Ruby chalice clarkia evolved alongside hummingbirds, its deep pink petals and tubular flower shape perfectly matched to the birds' feeding behavior. The flower's stamens extend just far enough that a hummingbird must push past them to reach the nectar, ensuring pollen transfer. Other pollinators visit these flowers, bees and butterflies among them, but the hummingbird's hovering flight and long bill make it the most effective pollinator for this particular plant. The female Anna's Hummingbird needs this concentrated energy source now more than ever. She is building a nest, a tiny cup of plant fibers and spider silk bound together and camouflaged with lichen, hidden in the fork of a willow branch. Each day she adds more material, and each day she must fuel both her own metabolism and the development of her eggs.The clarkia blooms will continue for several more weeks, their peak abundance timed to support not just the hummingbirds' nesting season but the broader community of pollinators that emerge in late spring. Native bees work the flowers in the afternoon heat, and Gray Buckeye butterflies visit when the light begins to soften toward evening. The pitted onion and Ithuriel's Spear add their own nectar sources to this seasonal feast, their purple and blue flowers creating a mosaic across the grasslands. Listen for the hummingbird's call, a sharp chip that cuts through the morning air, often repeated in rapid succession when she encounters another bird near her feeding territory. The sound carries farther than you might expect from such a small bird, a declaration that these particular flowers, this particular patch of hillside, are spoken for.
