Devil's Claws (family Martyniaceae)

Devil's Claws (Unicorn Plants) belong to American plant family Martyniaceae. In this taxon there are very original and useful species and numerous of them can be easily grown in the gardens or balconies in temperate areas. There are only 5 genus and 16-20 species in the family. The most characteristic for them all there is the appearance of fruit – it is fleshy, viscid, pubescent drupe (often described as „pod”) with long (in genus Proboscidea and Ibicella) or short (in genus Martnia, Craniolaria and Holoregmia) appendix, which breaks when ripe and unveil hard woody drupelet. Then the rostrum (part of drupelet which was inside of appendix) break for 2-5 parts which curve and become similar to claws. These claws help to transfer the seeds on legs of animals.

 

Proboscidea sabulosa (Sand Dune Unicorn Plant) is the smallest species in genus (more photos are bellow)

Martyniaceae species are protocarnivorous i. e. they catch the small insects (to viscid surface of leaves or stems) but do not digest them. Probably formerly, in early times, some present carnivorous plants were protocarnivorous and as a result of evolution they started to „eating” the animals.

Martyniaceae have very ornamental large colorful Gloxinia-like flowers and can be very ornamental. The drupelets are use in basketry and to making very interesting artistic sculptures (often very fairy as gargoyles, dragons, fantastic birds, unicorns etc.).

The young fruits of numerous species and theirs seeds (sometimes also leaves or roots) are edible. The fruits can be pickled – they are bitter but very tender and delicious. The seeds should be boiled before eating. They taste like sunflower seeds and have similar size but softer seedcoat. Immature seeds can be eaten raw.

The names of taxons which I tried to grow are bolded and below of each description there are visible their images. All photos were made by me in my garden and balcony in last a few years.

To the largest genus in the family – Proboscidea – belongs 7 species mainly annual herbs. I tried to grow 6 of them (5 with success so far). All species occur in North and Central America (except one which grows also in Peru).

Growing details:

All Martyniaceae love warm temperatures, fertile soil and much of sunlight. Some forms of the annual species as P. fragrans, P. parviflora, P. louisianica, P. sabulosa, P. triloba or Ibicella lutea are easy to growing in very warm spots in gardens or in medium size pots outside. They need short growing season (often only 3-4 months). But other forms/varieties of the same species are more difficult and later. P. sabulosa and P. althaeifolia need perfectly well drained sandy soil. Martnia sould be sown early (in March) inside and replanted outside after last frost and is very late (ripens in mid autumn). Others can be sown outside in May and fruits are usually ripe in September. The flowers can be hand-pollinated, but better make it the insects (bees etc.).The flowers of Proboscidea species have an interesting feature - the open stigma of the pistil closes quickly when it is touched during pollinating.

Propagation:

All species which I grown (maybe except Martynia annua) need the fluctuations of temparatures to seeds germinating so they should be sown outside or (if sown inside) on a heater. Some species are very easy to germinate as for example Proboscidea fragrans, P. parviflora subsp. parviflora var. hohokamiana or Ibicella lutea but some other need a pre-treatment before sowing. I discovered how to do it! The seeds of such difficult taxons should be soaked by 3-4 hours in solution of GA3 (300ppm) or (probably – I a not sure – I always used the hormone) clear water. Next it is needed to remove a seed-coat and seed-membrane (which covers young cotyledons and inhibits germination). Then seeds should be sown covering them in thick layer of powdered charcoal (to prevent of rotting the naked embrios). There is also one other method which I tested only in case of P. sabulosa so far – the seeds can be sown in cool cellar in pots in early March to germination after long time in May outside when the weather becomes warmer. In the case of Martynia seeds (which are very hard to removing from drupelets – you need use the nail pliers etc.) good is first method, but the soil substrate to sowing should be very special (composed only of sterile sand, powdered charcoal and vermiculite) because the germinating seeds are very susceptible to rotting.

Note:

The plants which belongs to family Martyniaceae are sometimes confused with one South African species - Harpagophytum procumbens (Grapple Plant, Wood Spider, Devil's claw) . The reason of it is the similarity of common names of both taxons. H. procumbens belongs to sesame family (Pedaliaceae) and is well known as a famous medicinal herb.

Descriptions of species:

The most widely used and highly prized species is Proboscidea parviflora ssp. parviflora (Doubleclaw, Red Devil's Claw, Desert Devil's Claw) native to south USA and Mexico. It is cultivated as large-fruit (to 16 inches = 40cm long) and white-seeds variety - var. hohokamiana (as edible and basketry plant). Wild - var. parviflora has black seeds and something smaller fruits. There are met 2-clawed and 3-5-clawed forms of both varieties. P. parviflora as species has the largest fruits in the family. The flowers are white or pale pink and have characteristic two purple spots in upper part of corolla. I tried to grow three named cultivars of white-seed variety: „Giant Multiclawed” (3-5 clawed), „Tohono O'Odham” and „Paiute”. The first one was very easy and early. The other ones were late and I had not a success with them. The multiclaw form (3-4 clawed) of black-seed variety, which I also grown, fruited less abundant but was also easy and rather early.

Proboscidea parviflora subsp. parviflora var. hohokaiana "Giant Multiclawed":

The flower have 2 purple spots on upper lobes of the corolla

Fruits are quite large

 

The flesh cover of ripe fruit breaks and fall down and there become visible the woody drupelet. 

 

The ripe dry drupelets

The seeds of this subspecies are white or gray.

 Proboscidea parviflora subsp. parviflora var. hohokaiana "Tohono O'odham":

Proboscidea parviflora subsp. parviflora var. parviflora "Multiclawed":

The drupelets of this variety of P. parviflora subsp. parviflora var. parviflora are similar to "Giant multiclaw" variety but they are smaller 

There are two other subspecies of P. parviflora: subsp. gracillima and subsp. sinaloensis. They have more flowers in inflorescences and occur in Mexico.

The most popular in trading is P. louisianica (Common Unicorn Plant, Devil,s Claw, Ram's horn). It is the most northern species in wild state (grows even in Canada). The seeds are brown or black, fruits medium size with two hard claws. It creates large pale pink or white flowers with yellow spot and small purple dots. I grown the two wild strains from Texas

 Proboscidea louisianica:

Seeds of Proboscidea louisianica are brown or almost black colored

The young seedling

Flowers are pale pink or white, without purple spots

The fleshy drupes

The ripe dry drupelets

 

The closest cousin to the last one there is P. fragrans (Sweet Unicorn Plant, Ram's Horn, Devil's Claws, Aphid Trap) sometimes described as P. louisianica subsp. fragrans. It differs from previous one by purple flowers and something smaller and softer drupelets. Not only fruits and seeds but also the leaves of this taxon were eaten boiled. This plant blooms so profusely that can be grown as petunias on balconies or hanging pots.

Proboscidea fragrans:

The young plants

The flowers are purple and fragrant

It can be a very ornamental balcony plant (not worse than petunias)

The young fruits are edible cooked

The plants can be quite large

The young boiled drupes

The ripening drupes

  The ripe dry drupelets 
 

The smallest fruits in the genus Proboscidea creates P. triloba (Mexican Devil's Claw, Cat's Claw, Uñas de Gato, Torito). They are not big but very bulgy and have relatively short appendix. Flowers, on long pedicels, are similar to P. louisianica. The leaves are sometimes trilobate (but not always). There are two varieties: var. triloba and var. diversifolia. The last one is more rare in wild state (in Mexico) than first. This species grows sometimes as a perennial in warmer areas but more commonly is an annual.

Proboscidea cf. triloba:

(my plant it is probably not a clear species - it has dentate leaf margin, dark spots on upper petals, cordate for deltate-shaped leaves (often 5-lobed) as P. triloba subsp. triloba but the colour of flowers is paler and fruits are larger then in descriptions of this species)

The young seedling

The leaves have dentate edge and flowers have purple spots

The plants can be quite large

Drupe has an inflated body and a short appendix

The ripe dry drupelets

There is also other, very little known species – P. sabulosa (Sand Dune Unicorn Plant). It is smaller plant which very differ of other species – it has relatively large, long, narrow seeds and small long purple flowers with original appearance. The fruits are something similar to next (look at below) species and drupelets have 4-angular lateral edge of claws (other species have rounded edge). It needs sandy fertile moist soil. It is very rarely met in wild state (only in south-west Texas, New Mexico and northern Mexico).

Proboscidea sabulosa:

The seeds are narrow and long (other than in rest of species)

The young seedling

Older seedling

The flowers are much other than in rest of species of this genus

This species plants are very small

The fleshy young drupes

The one fruit has been very twisted (more than other fruits) 

Mature drupe just after harvesting 

 

The ripe dry drupelets

There is visible the 4-angular lateral edge of claws

The only true perennial in the genus is P. althaeifolia (Golden Devil's Claw, Perennial Unicorn Plant). It creates thick tuberous taproot (which of an outer part is edible, as well as young fruits and seeds) and golden-yellow flowers. Drupes are very narrow, with not very thick seed-capsule part. Seeds are smaller than in case of other species. It grows in half-desert areas. In California it is often evergreen but it south Arizona the stems and leaves are dying in dry or cold periods. It has been the most difficult to growing species in my experience. My plants unfortunately died in young age. I am going to try again. It likes a heat, perfectly well drained soil (it is susceptible to rotting when young) and extremely full sun (the lacking of sunlight it is the often reason of dying of young plants in spring in northern temperate areas). This is the only species in genus Proboscidea which can be meet in wild state in South America (in Peru) but more often occurs in southern USA and Mexico.

Proboscidea althaeifolia:

The young seedlings

The young plant

  The ripe dry drupelets

There are numerous seeds inside of a drupelet

I found one rare 3-clawed drupelet 
 

The last species (which I have not grown yet) there is P. spicata (New Mexico Devil's Claw). Despite the common name it grows only in south-west Texas and in Mexico. It is the rarest species in wild state – the scientists do not even know how looks its fruit. It is only known that the flowers are purple (as P. fragrans) and pedicels very short so inflorescence looks as a spike (not as a raceme as in the case other species).

I grown also two other species of family Martyniaceae which belongs to another genus. Ibicella lutea (Yellow Unicorn Plant) - it is very similar to species in genus Proboscidea (differs mainly in details of flowers appearance) annual plant with yellow flowers and fruits similar to P. louisianica in size and shape but seed-capsule part is covered by short spines. It germinates always in small per cent and often slowly but it does not need any pretreatment before sowing.

Ibicella lutea:

The flowers are golden-yellow, very ornamental

The ripening drupelets

The ripe dry drupelet

The last species of this family which I grown is Martynia annua (Devil's Claw, Ice Plant, Tiger's Claw). There is the only one species in the genus. It is plant which gave a name to whole family. This is annual and straight herb - in contrast to other species in the family (which are rather procumbent). The flowers are very large, white with pink and yellow spots and fruits are very small, with very very short claws. Inside of the hard drupelets there are only four long seeds (in genus Proboscidea and Ibicella in fruits there are numerous ones) which are very difficult to germinating (very susceptible for rotting and need removing a seed-coat and seed-membrane – as described below). Martynia grows in a wild state in Central America.

Martynia annua:

 

The dry drupelets and the seeds

Young seedling

This plant is always straight, not spreading like Proboscidea spp.

The first developing flower

The unripe and ripe drupes

The ripe dry drupelets

The fleashy coverings of a fruit 

 

There are two South American genus yet which have very similar fruits to Martynia but differs of it in other features. It is Craniolaria - with two species: annual - C. annua (Yuca Escorzonera) which occurs in northern coast of South America and also Caribbean and tuberous perennial - C. integrifolia (Pico de Piraba) from South Brazil, Bolivia, Paraguay and Argentina. In last genus Holoregmia there is only one shrubby species – H. viscida (unknown common name) which grows in only in North-East Brazil (state Bahia).

I am looking for rare species of this family. If you have available the seeds of them please write to me.