Wayne Handlos

1. 2. 3. 4. 5.

6. 7. 8. 9. 10.

1.  Hypseocharis pimpinellifolius  2.California macrophylla  3.California macrophylla

4.  Erodium cicutarium (black structures/dots above sepals are staminodes.)

5.  H. pimpinellifolius (1857)   6. Pelargonium hispidum 7. Geranium repens

8.  Monsonia praemorsa 9. Hypseocharis tuberous roots (cm scale

10.  Hypseocharis pimpinellifolius from Das Pflanzenreich, vol. 130, 1930.


We usually say that the geranium family (Geraniaceae) consists of four or five genera: namely Geranium,

Erodium, Monsonia/Sarcocaulon and Pelargonium. But in a broader, botanical/taxonomic sense this

is not strictly correct.

Scientists continue to study and re-examine plants as new information and new techniques of analysis

become available. In recent times various aspects of plants have been (and continue to be) examined

for their DNA composition. Genetic relationships are now popularly analyzed by genealogists (via and 23andMe) to find hidden relationships among people. This same approach has also

been done to help us understand relationships between various species of plants. These techniques have

also been used within the geranium family and some of its close relatives. Hence we now get to know

about a new genus (named California) within the geranium family and a formerly recognized genus

(Hypseocharis) which seems to be more closely related to members of the geranium family than to any

other plant family.

The genus California was created for a plant which had first been collected in 1834. At that time it was

included with a number of other plants in the genus Erodium. In 1838 it was named Erodium macrophyllum.

In recent years, DNA studies have shown this species to be only distantly related to other species of Erodium,

so the decision was made to place this plant in its own category/genus � California. Several other species of

Erodium are found in North America and all but one (E. texanum) were introduced from the Old World. In

California they are common naturalized weeds.

Plants of Hypseocharis are perennial, tuberous herbs growing in the southwest Andes Mountains of South

America. They fit in the overall pattern of the geranium family with 5-15 anthers but are distinct in having multiple

ovules in each compartment of the ovary. In other words, unlike other members of the geranium family, they

produce more than five seeds per flower. The cotyledons (seed leaves) are spirally twisted unlike other members

 of the Geraniaceae. In the past, Hypseocharis had been placed in the Oxalidaceae but DNA studies show it

more closely related to the genera of Geraniaceae than any other plant family.


The following key will help you distinguish the various genera in the family Geraniaceae.

    1. Flowers zygomorphic (bilaterally symmetrical), with a nectar tube (hypanthium); stamens 2- 7 Pelargonium

    1. Flower actinomorphic (radially symmetrical), without a nectar tube 2

2. Seeds numerous, produced in a capsule; stigma capitate; stipules absent Hypseocharis

2. Seeds 5, beaked (tailed); stigma branched; stipules usually present 3

    3. Stamens 15 4

    3. Stamens 5-10 

4. Plants succulent; stems waxy and spiny Sarcocaulon*

4. Plants not succulent; stems not waxy; stems not spiny Monsonia*

    5. Stamens 10 Geranium

    5. Stamens 5 6

6. Staminodes 5 (sterile stamens) Erodium

6. Staminodes lacking California

*DNA studies indicate a close relationship between these two groups so even though they can be easily

separated morphologically, current taxonomic thought includes Sarcocaulon within the genus Monsonia.



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