californicum (Torrey) Coville
Fremontodendron decumbens R. Lloyd
Fremontodendron mexicanum A Davidson
× Chiranthofremontia lenzii Henrickson
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Fremontodendron 'California Glory'
The tribe Fremontodendreae consists of 3 or more species in 2 genera, from Guatemala, Mexico, Arizona and California. Chiranthodendron has a single species found in Guatemala and southern Mexico. It is a small tree, with showy reddish flowers. Fremontodendron has two (or more) shrubby, usually yellow-flowered, species in Baja California, California and Arizona. I follow the USDA  in recognising 3 species. The tribe also includes the intergeneric hybrid between these two genera, and the extinct genus Florissantia, with 4 species, from the western North America and the Russian Far East.
Fremontodendron was named after Major General J.C. Frémont, who was, inter alia, an explorer and amateur botanist in California. Chiranthodendron, "hand flower tree", is a descriptive name, and a calque of the native Mexican name. Florissantia is named after the classic fossil locality of Florissant, Colorado.
There has been some confusion as to the correct name of both genera. Fremontodendron has often been known as Fremontia. Humbert and Bonpland introduced the name Cheirostemon to replace Chiranthodendron; the variant spelling Cheiranthodendron also has considerably currency. Furthermore the tribe has been been known as Fremontieae rather than Fremontodendreae; J. Agardh  proposed a family Fremontieae (Fremontiaceae); and Asa Gray  a family Cheiranthodendreae (Cheiranthodendraceae, Chiranthodendraceae), both proposals being coterminous with the tribe.
[Note: Professor Reveal has brought to my attention the facts that Chiranthodendreae Baill. (1872) has priority over Fremontodendreae Airy Shaw (1965), and that the rules of plant nomenclature do not at the present allow the conservation of tribal names. Therefore, under the correct application of the International Code of Botanical Nomenclature, the tribe should be known as Chiranthodendreae. However the names Fremontieae and Fremontodendreae have long been used in the botanical literature instead of Chiranthodendreae. For the time being I am continuing to use Fremontodendreae.]
The tribe is composed of two genera. Chiranthodendron is a monotypic genus from Guatemala and southern Mexico. Fremontodendron has two or more species - there are several populations of uncertain rank - in northern Mexico and California. The unity of the tribe is evidenced by shared derived characters, such as the presence of only a single whorl of sterile floral parts, identified as the calyx (this apetalous trait is shared with Sterculieae, and with several other malvaceaous taxa including Cullenia, some species of Grewia and Triumfetta, and some members of Lasiopetaleae), a quinquncial arrangement in aestivation of the sepals, and the arrangement of the stamens, by the existence of inter-generic hybrids, and by DNA sequence evidence.
Kubitzk & Bayer  report chromosome counts of 40, and ca. 98, for Fremontodendron.
Fremontodendron is pollinated by bees , particularly the larger species; Chiranthodendron by bats  or perching birds.
I have an anecdotal report of respiratory tract irritation from the hairs covering the foliage and fruits of Fremontodendron. They are also known to cause contact dermatitis (including allergic sensitisation) and eye irritation, and wearing protection for skin is advised. My experience is that the hairs of the seed pod are particularly penetrating.
Fremontodendron californicum (Torr.)
Californian Flannelbush, Californian Fremontia, mountain leatherwood, Silver Oak, Slippery Elm
fremontodendron de Californie
Fremontodendron californicum is an evergreen shrub growing to between 2 and 9m, from California, northern Baja California and central Arizona. The leaves are, alternate, 5-10cm long, usually 3-lobed but sometimes entire, thin textured, with a pale brown impedimentum of small stellate hairs on the lower surface. The flowers, borne in late spring, are flat to widely cup-shaped, 2" or more across, with golden yellow sepals. The seed capsules are ovoid in shape, with a rounded or shortly pointed tip. The seed is dull brown or black in colour, and pubescent.
Geographical variation is recorded in Fremontodendron californicum. [map of California counties]
In the north of the range of Fremontodendron californicum, in Tehama county, can be found specimens with bright (as opposed to dull or dark) green upper surfaces to the leaves, and a whitish (as opposed to brownish, tawny or ferruginous) indumentum on the underside of the leaves. These have been named var. viridis Harvey. In the south of the range can be found specimens with entire (as opposed to lobed) leaves. Those in San Diego county have petioles longer than half the length of the blade, and have been named var. diegensis Harvey; those in Tulare and Kern counties have petioles one third to one half the length of the blade, and have been named var. integra Harvey. The remaining plants (excluding napense, obispoense, and crassifolia - see below), have been named as var. typica Harvey, but under current nomenclatural rules should be named as var. californicum. (However these varieties are not widely recognised as taxa.)
Plants in Nevada and Yuba counties approach Fremontodendron decumbens.
Fremontodendron californicum subsp. napense (Eastw.) Munz is a small-leaved, small-flowered, variety found on serpentine soils in Sonoma, Napa, Lake and Yolo counties in California. The indumentum on the lower surface of the leaves is initially whitish, but becomes ferruginous with age. The flowers sometimes have a pinkish cast. It is not widely recognised as being a taxonomically distinct variety of any rank.
Fremontodendron californicum subsp. crassifolium (Eastw.) Abrams is found in Santa Cruz county. It has longer hairs on the twigs and petioles, and larger flowers (to 2½" across). Again this is not widely recognised as being a taxonomically distinct variety of any rank.
Fremontodendron californicum subsp. obispoense (Eastw.) Munz is a population from San Luis Obispo county and northern Santa Barbara county. This has subentire leaves, thinner twigs and narrower (and acuminate) fruits. It has large flowers (to 2½" across). This is also not widely recognised as a taxonomically distinct variety.
Variation in other traits also occurs; for example there is a photograph showing a flower with prominent red-orange anthers, and another showing a flower with a reddish eye.
I have found no information on the morphology of the Arizonan population.
Synonyms of Fremontodendron californicum include Cheirostemon californicum (Torr.) Martinez, Chiranthodendron californicum (Torr.) Baill., Fremontia californica ssp. crassifolia (Eastw.) Abrams, Fremontia californica ssp. obispoensis (Eastw.) Munz, Fremontia californica var. diegensis M.Harvey, Fremontia californica var. integra M.Harvey, Fremontia californica var. napensis (Eastw.) McMinn, Fremontia californica var. typica M.Harvey, Fremontia californica var. viridis M.Harvey, Fremontia californica Torr., Fremontia crassifolia Eastw., Fremontia napensis Eastw., Fremontia obispoensis Eastw., Fremontodendron californicum ssp. crassifolium (Eastw.) J.H.Thomas, Fremontodendron californicum ssp. napense (Eastw.) Munz, Fremontodendron californicum ssp. obispoense (Eastw.) Munz, Fremontodendron californicum var. obispoense (Eastw.) Hoover and Fremontodendron napense (Eastw.) R.M. Lloyd.
Fremontodendron decumbens R. Lloyd
Eldorado Flannelbush, Pine Hill Flannelbush, Pine Hill Fremontia
Fremontodendron decumbens is a prostrate form, sometimes consided a subspecies of Fremontodendron californicum, found in a restricted area of the Sierra Nevada, in Eldorado County in California. It grows to a height of up to 2 ft and a spread of up to 10 ft. It has orange or coppery coloured flowers, about 3.5 cm across, borne from late spring to mid summer, and dark green leaves with 5 to 7 rounded lobes. Populations of Fremontodendron californicum in neighbouring Nevada and Yuba counties have similar traits.
Fremontodendron californicum ssp. decumben (R.M.Lloyd) Munz is a synonym of Fremontodendron decumbens.
Fremontodendron mexicanum A Davidson
Mexican Flannelbush, Southern Flannelbush
Fremontodendron mexicanum is similar to Fremontodendron californicum, but the leaves are generally 5-lobed, somewhat wider, and thicker textured. The flowers are larger, approaching 3" in diameter, more orange-yellow in colour, more starry in appearance and are borne from spring to autumn. The capsules are slender pointed, and the seed glabrous and glossy black in colour.
It was formerly found wild in the Peninsular Ranges of Los Angeles, Orange, San Diego and south west Imperial counties (southernmost California) and northern Baja California, where it grew in chapparal and cypress woodland habitats. Its range in the United States is now restricted to a few locations in San Diego county. It was known from a single location in Baja California, from which it may have been extirpated by a flood. Hence Fremontodendron mexicanum is endangered in the wild.
Synonyms of Fremontodendron mexicanum include Fremontia californica var. mexicana (Davidson) Jeps., Fremontia mexicana (Davidson) J.F. Macbr. and Fremontodendron californicum ssp. mexicanum (Davidson) E. Murray.
Fremontodendron californicum (Torr.) Cov. × Fremontodendron mexicanum A Davidson
Three cultivars of this parentage were raised (1970) and distributed (1973) by Rancho Santa Anna Botanic Garden .
Detailed description with photo-illustrations.
Fremontias are hardy only in warm areas, and are generally short-lived. They are, however fast-growing and flower young. They should be grown in well-drained, preferably poorish soil. They are intolerant of shade. Summer watering should be avoided when the plants are established.
They may be grown as a wall shrub, in which case the branches should be trained flat against the wall. In this case the previous year's flowering branches should be pruned back to 2 to 4 buds from the flowering branches in early spring. (RHS.)
Fremontias are propagated by seed or cuttings. Seed should be sown, or cuttings planted, under glass in late spring, at a temperature of about 15°C. The dormancy of Fremontodendron seed can be difficult to break . It requires chilling at 5°C for some months, followed by mechanical scarification or heat treatment. A suitable heat treatment is to place in water at 85 to 90°C and allow to cool for 12 to 24 hours.
Young plants should be overwintered in frost-free conditions, and planted out after the last frosts.
Devil's Hand Tree, Mexican Hand Tree, Monkey's Hand Tree
árbol de la manita, flor de la manita, macpalxochiquauhitl, majagua, mano de león, mano de mico, palo de yaco
Chiranthodendron pentadactylon is a small to medium sized evergreen tree from Guatemala and southern Mexico, which can reach 50 or more feet in height, and about half this in breadth. It has large shallowly lobed leaves, with a woolly brown indumentum on the underside. It flowers in late spring and early summer, bearing unusual flowers. These have the appearance of a red 'claw' with long stamens appearing as digits rising from a maroon coloured calyx - hence the vernacular name. The fruits are 5 inch long, 5 lobed, dehiscent, tomentose, woody capsules.
The species was long known to science from a single specimen in an ancient cultivated setting in central Mexico, outside the natural distribution. There was a superstition that it was divinely limited to a single specimen.
It was also used in traditional Mexican medicine.
Chiranthodendron pentadactylon is said to be able to tolerate 5°C of frost. It should be grown in full sun, in a well-drained location. (It may well not be hardy in the British Isles; many plants with similar requirements can't handle either prolonged frosts, winter wet, or low light levels.)
Dahlia wilt, Verticilliatum dahliae (which infects a wide variety of plants - not just Dahlias), is reported from Chiranthodendron in New Zealand.
Synonyms of Chiranthodendron pentadactylon include Cheirostemon apetalum Cerv., Cheirostemon platanoides Humb. & Bonpl. and Chiranthodendron platanoides Baill..
×Chiranthomontodendron lenzii Dorr
×Chiranthofremontia lenzii is an inter-generic hybrid between Chiranthodendron and Fremontodendron 'Pacific Sunset'. Its flowers are intermediate; they have the golden colour of Fremontodendron, but the disposition of the stamens is similar to Chiranthodendron.
×Leelenzia ranchorum is a name which has been applied to the cross Chiranthodendron pentadactylon × Fremontodendron 'California Glory'. According to the International Code on Botanical Nomenclature (ICBN) this is invalid.
×Chiranthofremontia lenzii is a name which has been applied to the cross Chiranthodendron pentadactylon × Fremontodendron 'Pacific Sunset'. This is also invalid according the ICBN.
Specimens of Fremontodendreae are reported from the Florrisant Formation of the Eocene of Colorado. Specimens of Fremontodendron are reported from the Miocene of Baja California and California. Pollen of Fremontodendron is reported from the Late Palaeocene and Miocene of California
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Fremontodendron 'California Glory'
If you have found any errors on this page, or have any further information about the genera Chiranthodendron and Fremontodendon then please contact me at firstname.lastname@example.org.
© 2002, 2003, 2005, 2007, 2008, 2009, 2012 Stewart R. Hinsley