FRITHIA

This miniature leaf succulent is attractive even when not flowering as the windowed leaves with crenulate markings are showy and unique.
Description
This minute plant comprises a cluster of succulent, spirally arranged leaves, windowed at the tips. The windows are just visible above the soil surface and thickened rootstocks are formed underground.

The stems are much reduced and during periods of drought the plants retract into the sandy soil. This has been thought to be achieved by means of contractile roots, but no such roots have been found. The cells of the leaves are arranged in columnar rows and when moisture is lost and the contents shrink, the tangential walls contract, drawing the plants deeper into the soil. This this way they avoid desiccation during the dry winter months and times of drought. Retraction into the ground is thus achieved by means of contractile leaves, not contractile roots.
Flowers are white with a yellow centre, sometimes tipped with light pink. They are generally about 15-20 mm in diameter and are borne singly on very short stalks or are stalkless. They are subtended by five unequal sepals closely resembling the cylindrical leaves. The petals number between 20 and 30 and usually have acuminate tips. After pollination flowers turn pink or yellow.
Fruits are very delicate, spongy capsules resembling a barrel and open when wetted and close again when they dry out (hygrochastic capsules). However, the capsules become detached from the plants and break up shortly after ripening, releasing the seeds. This is an unusual feature as most other capsules in the family are woody and open and close repeatedly as they become wet (open) and dry (closed).

Distribution
Frithia humilis is one of a few mesembs growing exclusively in the summer-rainfall region of South Africa. It is restricted to two provinces of South Africa, namely Gauteng and Mpumalanga. 

This plant is Red Listed as Endangered ( IUCN Species Survival Commission 1994) as only nine subpopulations are known (Burgoyne et al. 2000). One subpopulation was lost because of pressures on the habitat. All the populations together cover less than 2 hectares. The populations are severely fragmented but many seed capsules are produced every year and plants seem healthy.
http://www.plantzafrica.com/plantefg/frithhum.htm


Frithia Pulchra





Frithia humilis




LITHOPS SPECIES



  • Lithops amicorum D.T.Cole

  • Lithops aucampiae L.Bolus


  • Lithops aurantiaca L.Bolus


  • Lithops bella N.E.Br.
  • Lithops brevis L.Bolus
  • Lithops bromfieldii L.Bolus 

  • Lithops christinae de Boer
  • Lithops chrysocephala Nel
  • Lithops coleorum S.A.Hammer & R.Uijs


  • Lithops comptonii L.Bolus 

  • Lithops dabneri L.Bolus
  • Lithops damarana N.E.Br.
  • Lithops de-boerii Schwantes
  • Lithops deboeri [2]
  • Lithops dendritica Nel
  • Lithops dinteri Schwantes 

  • Lithops diutina L.Bolus
  • Lithops divergens L.Bolus

  • Lithops dorotheae Nel

  • Lithops eberlanzii N.E.Br.
  • Lithops edithae N.E.Br.
  • Lithops eksteeniae L.Bolus
  • Lithops elevata L.Bolus
  • Lithops elisabethae Dinter
  • Lithops elisae de Boer
  • Lithops erniana Tisch. ex Jacobsen
  • Lithops farinosa Dinter ex Jacobsen
  • Lithops framesii L.Bolus
  • Lithops francisci N.E.Br.

  • Lithops friedrichiae N.E.Br.
  • Lithops fulleri N.E.Br. [2]
  • Lithops fulviceps N.E.Br.

  • Lithops gesineae de Boer

  • Lithops geyeri Nel

  • Lithops glaudinae de Boer
  • Lithops gracilidelineata Dinter 

  • Lithops gulielmi L.Bolus
  • Lithops halenbergensis Tisch.
  • Lithops hallii de Boer 

  • Lithops helmutii L. Bolus

  • Lithops hermetica D.T.Cole

  • Lithops herrei L.Bolus

  • Lithops hildegardi Hort. ex Oesterr.
  • Lithops hillii L.Bolus
  • Lithops hookeri Schwantes 

  • Lithops inae Nel
  • Lithops inornata Dinter ex Jacobsen
  • Lithops insularis L.Bolus
  • Lithops jacobseniana Schwantes
  • Lithops julii N.E.Br.

  • Lithops jutteri Hort. ex Oesterr.
  • Lithops karasmontana N.E.Br. 

  • Lithops koelemanii de Boer
  • Lithops kuibisensis Dinter ex Jacobsen
  • Lithops kunjasensis Dinter
  • Lithops lactea Schick & Tisch.
  • Lithops lateritia Dinter

  • Lithops lericheana Dinter & Schwantes
  • Lithops lesliei N.E.Br. 

  • Lithops lineata Nel
  • Lithops localis (N.E.Br.) Schwantes
  • Lithops lydiae L.Bolus ex Jacobsen
  • Lithops marginata Nel
  • Lithops marlothii N.E.Br.
  • Lithops marmorata N.E.Br. 

  • Lithops marthae Loesch. & Tisch. ex Jacobsen
  • Lithops maughani N.E.Br.
  • Lithops mennellii L.Bolus
  • Lithops meyeri L.Bolus

  • Lithops mickbergensis Dinter
  • Lithops mundtii Tisch.
  • Lithops naureeniae D.T.Cole

  • Lithops nelii Schwantes
  • Lithops olivacea L.Bolus 

  • Lithops opalina Dinter
  • Lithops optica N.E.Br.
  • Lithops otzeniana Nel

  • Lithops peersii L.Bolus
  • Lithops pillansii L.Bolus
  • Lithops pseudotruncatella N.E.Br. 

  • Lithops pulmoniuscula Dinter ex Range
  • Lithops rooi Hort. ex Oesterr.
  • Lithops rouxii Hort. ex Oesterr.
  • Lithops rubra N.E.Br.
  • Lithops rugosa Dinter
  • Lithops ruschiana N.E.Br.
  • Lithops ruschiorum N.E.Br. 

  • Lithops salicola L.Bolus

  • Lithops schickiana Dinter
  • Lithops schwantesii Dinter 

  • Lithops steineckeana Tisch.
  • Lithops streyi Schwantes
  • Lithops summitatum Dinter
  • Lithops terricolor N.E.Br.


  • Lithops translucens L.Bolus
  • Lithops triebneri L.Bolus


  • Lithops turbiniformis N.E.Br


  • Lithops umdausensis L.Bolus
  • Lithops urikosensis Dinter


  • Lithops vallis-mariae N.E.Br.


  • Lithops vanzylii L.Bolus


  • Lithops venteri Nel

  • Lithops verruculosa Nel


  • Lithops villetii L.Bolus 


  • Lithops viridis H.A.L


  • Lithops weberi Nel


  • Lithops werneri Schwantes & Jacobsen