Nature Profiles

Flora of Riparian Areas & Grasslands

 

Grassland Flora

Krameria lanceolata (Trailing Krameria)

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K.lanceolata scrambling through Agave schottii colony, Molino Basin, Santa Catalina Mountains

Characterised by its beautiful magenta flowers, which have a forward-curved lower petal, and round, spiny fruits, this sprawling shrub is common from Arizona eastwards in dry, sandy habitats. 

The two other Arizona Krameria species (K.grayi and K.parvifolia) differ in flower shape and colour.

 

 

Agave schottii var. schottii (Shindagger)

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Kartchner Caverns SP

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Molino Basin, Santa Catalina Mountains

The common name of this widespread plant comes from the common experience of many who have walked through its grassland habitat, where the plants often lurk unobserved until they are 'discovered' by the legs of an explorer. 

It is a cold-tolerant species, extending to high elevations in the Sonoran and Chihuahuan Deserts.  Unlike most other Agave species the leaves of Shindagger are untoothed along their margins, bearing coarse fibres instead, giving the plants the appearance of stemless Yuccas

A second variety of this species, treleasei, is a very rare plant with wider leaves and is found only in the Santa Catalina Mountains.

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Agave chrysantha (Golden-flowered Agave)

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Molino Basin, Santa Catalina Mountains

This uncommon upland Agave is endemic to central Arizona, growing in grassland and pine-oak forest at moderate elevations.  It does not occur in lowland desert areas. 

When in flower, the species is unmistakable due to the intense yellow flower colour, but vegetatively the species closely resembles Agave palmeri, although the range of each species does not overlap. 

Thanks to John Wiens for the identification.

 

 

Yucca baccata var. brevifolia (Banana Yucca)

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Molino Basin, Santa Catalina Mountains

The most striking feature of this widespread Yucca is the lack of a trunk.  Leaf rosettes grow at ground level, and in spring are topped with a typical flower spike, which barely reaches above the leaves.  Individual leaves are shaprly pointed, incurved and have curved, frayed fibres. 

A cold adapted species, Banana Yucca is especially common in the northern deserts (Mojave and Great Basin), and is uncommon in southern Arizona, except in higher altitude grasslands.  The common name derives from the banana-like fruits, which are edible but do not taste like bananas! 

Thanks to John Wiens for the varietal identification.

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Nolina microcarpa (Beargrass)

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Molino Basin, Mt Lemmon, Santa Catalina Mountains

The most widespread of Arizona's four Nolina species, N. microcarpa can be recognised by its stiff grass-like leaves, which tend to have frayed tips with loose fibres.  The flowering stalks (old ones are visible on this plant) are also often crooked or bent.

The other Nolina species in Arizona are N.bigelovii & N.parryi, both species of north-western Arizona, and N.texana, which is a Chihuahuan Desert species found in the far south-east of Arizona.  Each species differs in leaf, flowering spike and fruit characteristics.  N.microcarpa is an upland plant, unlike the other three species.

 

 

Riparian Plants

Fraxinus velutina (Velvet Ash)

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Santa Catalina Mountains

Common along watercourses in southern Arizona, Velvet Ash grows to a large, elegant tree.  It can be recognised by its compound leaflets, composed of ovate, shallowly toothed leaves.  The upper surface of these is covered with tiny velvety hairs, hence the Latin name of the species. 

Velvet Ash can be seen in all southwestern States, fron California to Texas.

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Sabino Canyon

 

 

Populus fremontii (Fremont Cottonwood)

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Madera Canyon, Santa Rita Mountains

This large-growing tree is especially prominent along stream banks and river margins, as well as in wetland habitats (where they still remain).  The leaf shape of Cottonwoods is often variable and species hybridise readily, but overall they have typically triangular leaves on long, thin stalks.  Leaf margins have rounded shallow teeth.

 

 

Alnus incana ssp. tenuifolia (Thinleaf Alder)

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Pinaleno Mountains

Thinleaf Alder is a fairly rare tree in Arizona, restricted to stream banks in cool, upland canyons.  It can be recognised by its wrinkled, heavily-veined ovate leaves with pointed tips. 

Nationally this species is common through the Rocky Mountain states and on into Canada.  The other subspecies of A.incana (ssp.rugosa) is a tree of the northeastern United States and does not occur in our region.  Alnus oblongifolia (Arizona Alder) is also widespread in the state.

 

 

Marah gilensis (Wild Cucumber)

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Catalina State Park

The bizarre-looking member of the gourd family (Cucurbitaceae) grows as a straggly vine in thickets along washes and other riparian habitats.  The large, lobed leaves have a distintive shape, and when the prickly pointed fruit is present this species will not be confused with any other. 

M.gilensis is the only member of the genus in Arizona (and New Mexico), but five other species are found in California, including two endemics.

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Claytonia perfoliata (Miner's Lettuce)

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Catalina State Park

This spring-flowering wetland annual is easily recognised by its circular leaves which completely surround the stem.  Each stem is topped by a cluster of small five-petalled flowers. 

Miner's Lettuce is a variable and widespread species, with all three American subspecies found in Arizona (ssp. intermontana, mexicana and perfoliata).

 

 

Prunus serotina (Black Cherry)

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Pinaleno Mountains

Very similar in overall appearance to the widespread Common Choke Cherry (P.virginiana), Black Cherry can be distinguished by close examination of the fruits - they retain the flower sepals on the underside of the cherries, unlike Choke Cherry.  Both species occur in Arizona, with the state respresenting the south-western limit of Black Cherry's range in the United States.

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Platanus wrightii (Arizona Sycamore)

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Madera Canyon, Santa Rita Mountains

This common tree of mountain canyons and riparian areas is described in the Flora of the Pine-Oak Woodlands section of the site.

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Mimulus guttatus (Yellow Monkeyflower)

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Chiricahua Mountains

Along seepages and streams this species is a common sight, and the plant can form extensive mats covering the wet ground.  As a species, Yellow Monkeyflower is unlikely to be confused with any other in Arizona, although in other states the genus is more diverse. 

M.guttatus is very widespread in the United States, found in all western states and scattered localities in the north-east.

 

 

Stemodia durantifolia (Whitewoolly Twintip)

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Mt Lemmon

Primarily a Central and South American species (it is found as far south as Chile), this little riparian herb is easily recognised when its purple tubular flowers are present.  The whole plant is covered in sticky glandular hairs, and the sessile leaves are borne in opposite pairs.

Thanks to John Wiens for the identification.