RUBIACEAE

Plants herbs, shrubs, trees. Leaves simple, usually entire, opposite or apparently whorled, the additional leaves modified stipules.  Flowers usually bisexual, radially to slightly bilaterally symmetric. Calyx 2-6-lobed or lacking; corolla united, 4-6-lobed; stamens 4-6, epipetalous and alternate with the petals; carpels 2, united; ovary inferior, usually with 2 locules; style 1; stigma capitate or branched; ovules 1-many per locule. Fruit a capsule, berry, or drupe.

Only two genera of Rubiaceae grow naturally in northern Utah and only one, Galium, has species that are native to the area. The other, Rubia, has become established in some disturbed sites. The family has two commercially important genera: Coffea, the source of coffee, and Cinchona, the source of quinine.  Kelloggia is included in the key below because it grows to the north, east, and south of the region covered by Shaw’s flora.  Gardenia is included because of its potential as an ornamental species. 

All members of the Rubiaceae have stipules. In some species, the stipules from the opposite leaves are shorter than the leaves but are fused together, forming a single, leaflike structure between the leaves. In other species, the stipules are similar to the leaves in size and may be fused or divided so that the species appear to have whorled leaves. 

Heterostyly is common in the family.  I would be interested in knowing which of our local species exhibit it. 

1 Plants mostly woody, shrubs or trees; in northern Utah, known only in cultivation (2)
1 Plants mostly herbaceous, sometimes woody at the base; some species wild, others cultivated (4)

2 Flowers more than 7.5 cm across Gardenia
2 Flowers up to 5 in long (3)

3 Corolla tube slender, 2-3 times longer than the lobes Ixora
3 Corolla tube shallow, shorter than the lobes Coffea

4 All leaves opposite, the stipules small................................................................... Kelloggia
4 Most leaves apparently whorled, the upper leaves sometimes opposite (5)

5 Corolla funnelform, the tube equaling or almost equaling the lobes in length Asperula
5 Corolla rotate or nearly so, the tube much shorter than the lobes (6)

6 Corolla 3-4-lobed; fruit dry; several species native or naturalized Galium
6 Corolla 5-lobed; fruit fleshy; needs a greenhouse in northern Utah Rubia

ASPERULA L. Woodruff

Plants annual or perennial, herbaceous. Leaves apparently whorled (some of the leaves actually stipules). Flowers 3-10 mm long, many; calyx inconspicuous; corolla funnelform; style branches unequal; ovules 1 per locule. Fruits usually dry.

Asperula is generally known as a cultivated species, but there is a tentative report of A. odorata growing outside of cultivation in northern Utah.  [The folks in the Intermountain Herbarium would be delighted to examine a specimen so that the report can be verified or modified].

Asperula odorata L. Sweet Woodruff. Plants rhizomatous, smelling of vanilla.  Stems 15-50 cm tall, erect to ascending, with retrorsely hispid nodes, otherwise glabrous. ‘Leaves’ mostly in whorls of 6-10, usually 8, 1.5-5 cm long, 4-12 mm wide, antrorsely scabrous-ciliate on the margins, sometimes also on the midribs on the underside of the leaves. Inflorescence terminal, branched. Corolla 3-5 mm, white, the lobes usually slightly longer than the tube. Fruit about 3 mm, covered with hooked bristles. 

Some links: Picture; reported (NOT VERIFIED) medicinal values

COFFEA L.  Coffee

Plants evergreen shrubs or small trees. Leaves mostly opposite, sometimes in 3s. Flowers in axillary clusters; calyx with 4 or 5 lobes, united below; corolla cream or white, salverform, the tube shorter than the lobes; ovules 2. Fruit a berry.

Coffea arabica L.  Arabian Coffee.  Shrub. Leaves 7.5-15 cm long, dark glossy green, opposite, elliptic. Corolla pure white, fragrant, the lobes about 2 cm long. Fruit about 1.2 cm long. An African species, introduced very early on to the Arabian peninsula.

GALIUM L.
Plants herbs or shrubs, with square, often retrorsely scabrous stems. Leaves opposite but apparently whorled, the additional leaves actually stipules. Calyx lacking; corolla (3)4-lobed small, rotate or nearly so; ovary with 2 locules; styles 2, short; stigmas capitate; ovules 1 per locule.

Galium has approximately 300 species in total. It is widely distributed but particularly common in temperate regions.